The New York Times has a nice article on hospitals that allow patient's pets to visit. This is a controversial area, with policies (when they are actually present) that range from wide-open access to complete prohibition. Like most things in life, there's a middle ground that's the most reasonable.
The positive aspects of people being allowed to have their animals come visit are pretty obvious, since people may have close bonds with their own pets and having a chance to see their pets might make a big difference to their mental state/well-being, particularly for someone who is chronically ill.
The negative aspects are less clear. We certainly know that pathogens can be transmitted from animals to people (and in the other direction too), and people in hospitals are often at higher risk of infection and complications thereof. There's a list of pathogens we worry about, but there's a serious lack of data to help determine the severity of the risk - and how to reduce it. Organized pet therapy programs are great because they are structured and there can be a lot of scrutiny and training of the pet and handler. Visits by patients' own animals are inherently less controlled, since the individual animal and handler don't undergo the same degree of assessment and training.
I get asked to review visitation guidelines frequently, and a reasonable middle-ground can usually be found. These are some snippets from the NYT article that highlight common points.
A doctor’s order allowing the family pet to visit is typically necessary...
That's a good approach, although it's not often used. This lets the doctor decide if it is reasonably safe to have the pet visit, i.e. the patient is not at a very high risk of infection. The weak link here is sometimes the doctor, because sometimes the doctor doesn't understand the risks associated with pet contact and may not identify a concern. Other times, the doctor may not understand the relatively low risk and the potential benefits, and therefore default to banning visitation without giving it much thought. I think that's less common these days but still an issue.
...as is an attestation from a veterinarian that the animal is healthy and up to date on all its shots.
The first part is great: making sure there are no health or behavioural issues with the animal that would pose an increased risk. The second part is very common but largely represents a lack of understanding of the issues. Too often, "has he had his shots?" is the main question that's asked about the animal, despite the fact that it's largely irrelevant from a zoonotic disease standpoint. Yes, we want to make sure the pet's rabies vaccination is up-to-date, but the other core vaccines are irrelevant from a human health standpoint (although they're very important for keeping the animal healthy overall).
Most institutions require that dogs — the most common visitors, by far — be groomed within a day or so of a visit and on a leash when they walk through hospital corridors.
Standard and logical policy. Grooming might help reduce the burden of bacteria, fungi and parasites on the haircoat, as well as a lot of loose fur and dander that could otherwise contaminate the hospital environment.
Cats must be taken in and out of the institution in a carrier.
Logical. Some cats do well on leashes but it's better to have a cat in a carrier when taking it through a strange area. It also helps prevent other people from coming into contact with it.
If a dog or cat wants to get up on a patient’s bed, a covering is laid down first.
Good policy, and it protects both the patient and the animal.
If an animal seems agitated or distressed when it comes into the hospital, staff members who meet the family and escort them to the patient’s room have the right to turn it away.
This has two important components. One is that the visitation is supervised, which is great. The other is that staff are given the ability to intervene in the unlikely even that there are problems.
If the patient shares a room with someone, that person must agree before a pet may visit.
This is often overlooked. Roommates might be afraid or allergic, and in those situations, visitation shouldn't happen in a shared room. There might be a way to do the visit in another room, so it doesn't necessarily preclude the visit from happening. This has to be broached in advance and in a manner that the roommate doesn't feel pressured into consenting. It's best done by having the patient's healthcare providers approach the other patient and/or the other patient's family.
There's always some risk with animal hospital visitation. That's never going to be eliminated, but a lot of common sense practices can reduce the risk to a very low level, hopefully to the point that the risk is overwhelmed by the benefits. A little structure and a lot of common sense go a long way.
It's maybe a sad statement that reading about someone whose diseased toes were gnawed off by their dog doesn't shock me anymore. It's not an everyday event but it's far from rare. An Indiana man learned about this the hard way when he woke up thinking his dog was licking his toes, when in fact, the dog had eaten them.
As is typical in cases like this, the person is a diabetic and had a foot infection, which contributed to the dog being attracted to the toes and the person not feeling the midnight snacking. Presumably, the person will be fine with some wound care and antibiotics. In fact, the dog may have just altered the manner of amputation if the toes were that severely affected. They may have been coming off one way on the other in the near future, but this is still not the desired approach.
A couple of questions come up sometimes in cases like this.
Is the man at risk of any infections from the dog?
- Certainly, there are concerns. This should be treated just like a bite since there was obviously contact between dog saliva and broken skin. Antibiotics were presumably already being used because of the toe infection, so that might have been enough, but antibiotic treatment would be needed in a situation like this given the type of exposure and the person's compromised state.
- Rabies is unlikely but it still has to be considered. This is just like a bite, so a 10 day observation period of the dog would be indicated. There's almost zero risk of rabies here, but when we're talking about rabies, "almost" isn't good enough.
Is the dog at risk of catching anything from the owner?
- This is perhaps the more likely of the two concerns. The dog was licking and eating infected tissue. Many of the bacteria that cause this type of infection can also infect dogs. The odds of the dog developing disease from this are pretty low. It's more likely the dog would become a carrier of the bacterium for a while (e.g. in its mouth, nose, or intestinal tract). If the dog is otherwise healthy, it's probably not going to suffer any consequences, but knowing what bacterium was causing the toe infection would help with that risk assessment.
While dogs amputating toes is rare, it's surprising how often I hear about people who let their dogs lick diabetic ulcers. As well, I've heard of people who have looked down and realized their dog or cat was gnawing on their toes (not amputating - at least not yet - but chewing away nonetheless). Usually, these are diabetics. Usually, nothing bad will happen. However, a dog's mouth contains many different bacteria that can cause severe illness given the right situation, and chewing on a toe of a diabetic patient in particular would fit into that "in the right situation" category.
An outbreak of equine herpesvirus type 1 (EHV-1) has resulted in implementation of a quarantine at Woodbine, a major Thoroughbred track in Toronto. This outbreak is unrelated to the recent outbreak at an Ontario Standardbred training facility.
The Ontario Racing Commission has issued the following release:
The Ontario Racing Commission (ORC) announced that there have been five confirmed reports of the neurotrophic form of EHV-1 in thoroughbreds residing in Barn 1 at Woodbine Racetrack. One horse was euthanized on June 10 after becoming recumbent with a fever. A second horse in the same barn (Barn 1) also had a fever and showed neurological signs. The second horse was transported to the Ontario Veterinary College for further evaluation and treatment.
Thoroughbred racing will continue at Woodbine. However, due to the infectious nature of this disease, the ORC has ordered the implementation of various infectious disease protocols to protect our equine athletes.
In order to determine any further spread of the disease to horses in other barns, no horses are to exit Woodbine Racetrack without ORC approval for the next 7 days (June 19). This restriction may be reviewed based on the progression of the disease.
In addition, no horse is allowed in or out of Barn 1 or Barn 3 for the next 7 days, including training. This restriction may be reviewed, based on the progression of the disease.
All horses stabled at Woodbine must have their temperatures taken and recorded visibly on the horse’s stall door for inspection. Trainers with horses that have clinical signs consistent with EHV-1 infection (including fever (101.5 F/38.5 C or above), respiratory signs (cough, nasal discharge and/or neurological signs) must report these findings to their veterinarian immediately.
Horse people who had horses at Woodbine Racetrack within the last 7 days should monitor their horses for any signs of illness. Standardbred horses are not stabled at Woodbine Racetrack. As well, the standardbred racing meet concluded at Woodbine on May 20, 2013 and moved to Mohawk Raceway on May 23. Therefore the June 15 North American Cup at Mohawk will not be impacted by these measures.
As with most outbreaks, the next few days are critical to see how far the virus has spread. Early on, you never know whether it's confined to a specific barn or group, or whether it's widely disseminated across the facility. An outbreak that just affects one barn is still a problem, but it's much easier to contain than one that's already moved beyond the initial group. Without knowing how the first horse was infected (something that's rarely identifiable), time and testing are needed to determine the extent of the spread and how hard it will be to contain it.
Several dogs at a Miami humane society were quarantined last week because of concerns (or possibly panic/over-reaction) about methicillin-resistant Staphylococcus aureus (MRSA). MRSA in dogs is a concern because it's an important cause of infection in both people and animals. However, it's an opportunist, meaning it typically doesn't cause disease when it encounters a normal, healthy person or animal. In fact, a small percentage (~1-3% probably) of the human and pet populations carry this bacterium in their nose without knowing it, and the vast majority never suffer any consequences.
It's often tough to strike the right balance when dealing with an MRSA issue. We want people to realize that it's an important cause of disease and that it needs to be taken seriously, but we also want people to keep it in perspective and not freak out.
The Miami shelter report seems to be on the "freak out" side, particularly on the part of the local media.
It's not really clear what's happening based on this fairly poor article. The shelter's Chief Medical Officer, Dr. Maureen Swan, is quoted as saying there's a routine respiratory disease cluster in the shelter, but MRSA rarely causes respiratory disease in dogs. The article then adds Dr. Swan said it was "not the highly contagious MRSA virus." I have no idea what that means, and MRSA is not a virus.
My suspicion is that they have respiratory disease caused by the typical bacterial and/or viral pathogens that are commonly found in shelter dogs, and that they isolated a methicillin-resistant staph that just happened to be hanging around in that particular dog (since such bacteria normally live in the mouth, nose and skin). It's also not really clear whether this is MRSA. The article says MRSA, but the first thing I ask when I get an advice call about MRSA is "what staph species does the report say was isolated?". Most often, it's Staphylococcus pseudintermedius or another staph. These bugs can still be relevant, but they don't carry the same human health risk as MRSA, so it's important to know exactly what's been found.
Finding MR staph, including MRSA, isn't unheard of in a shelter. It's just one of many reasons that good general infection control practices are needed in these facilities. When MRSA is found, taking some extra precautions is reasonable because of the potential for disease and transmission to people, but too often people panic. It's understandable based on concern about MRSA and the scary stories people can find with a quick Google search. Not uncommonly, there's a combination of an short-term overly aggressive response while at the same time failing to improve basic infection control practices, which are the most important.
More information about MRSA can be found on the Worms & Germs Resources - Pets page.
The latest edition of the University of Guelph Animal Health Laboratory's newsletter contains an interesting report about 4 horses that died over the past few years from what was suspected to be contaminated intravenous fluid solutions. These cases were dead horses that were submitted for post-mortem examination from three different farms, so if anything, this could be an underestimation of the problem.
The first two horses were from the same farm. They were young Thoroughbreds that were routinely treated with intravenous electrolytes, vitamins and minerals (whether by the trainer or veterinarian is unknown). The first horse was found with its head hanging low after treatment. It later developed seizures and died. The second horse showed similar signs. The bacterium Klebsiella pneumoniae was isolated from a few different tissues of the first horse, as well as one of the "jugs" used to administer the fluids. The second horse had the same general lesions as the first, but Klebsiella wasn't isolated; however, this may have been because the body wasn't in great shape by the time it was submitted to the lab, and various other bacteria had overgrown the Klebsiella, making it difficult to isolate.
Another case was a young Standardbred that died after receiving intravenous fluids with vitamins, and a glyceryl guaiacolate jug. It had signs of bloodstream infection (septicemia) and Klebsiella oxytoca was isolated from multiple organs. Various bacteria were isolated from remnants of fluid in treatment bottles.
The final case was a five-year-old Standardbred that died after receiving a home-mixed vitamin jug. It had lesions similar to the other horses and consistent with a bloodstream infection. Klebsiella oxytoca was isolated from multiple organs.
Contamination of multidose drug vials or fluid solutions can occur if bacteria are inoculated into the bottle with a needle when a dose if withdrawn. We've shown this happens with multidose vials in a hospital situation, and of the farm it's even more likely to occur because it's a dirtier environment and, in the case of farm personnel, individuals have less experience with sterile technique. Fluid solutions can be contaminated in the same manner or when something is added to the fluids (e.g. vitamins). Contamination of reused fluid administration sets (i.e. fluid jugs/bags and the IV tubing) is quite likely, and that's why use of sterlie, single-use administration sets is recommended. Adverse events from a little bit of contamination are uncommon, but as shown here, they can happen and they can be severe. There's no information about what contributed to the contamination in these cases, but it's almost certain that poor infection control practices were at the root of the problem. Trying to save money by skimping on sterilization, reusing items without proper care, and using poor hygiene practices in general can end up costing much more.
Darwin's back in the news. He’s a young macaque who is often called the "Ikea Monkey" since he was found wandering around a Toronto Ikea parking lot one day last winter in a designer winter coat. He was seized because of a Toronto bylaw prohibiting monkeys as pets, and transferred to a local primate sanctuary. His owner, Yasmin Nakhuda, has been waging a high profile battle to get him back. There are numerous Facebook pages dedicated to freeing Darwin, and she apparently sent him a birthday greeting (perhaps not realizing it's unlikely that he had internet access at the sanctuary... or can read).
Anyway, Ms. Nakhuda is suing for custody and the trial is currently underway. Needless to say there's a lot of drama in the courtroom as Ms. Nakhuda tries to regain custody of the animal she calls her "son." Much of the trial has centred around issues of property, which I guess makes sense since that’s the main legal avenue.
However, what’s not been mentioned are the greater concerns, namely does Darwin pose a risk to the public and does Ms. Nakhuda pose a risk to Darwin? I think the answer to part 1 is certainly yes, and the answer to part 2 is maybe.
The first question (does Darwin pose a risk to the public) is easy. There are a variety of issues with keeping non-human primates as pets. They can be destructive, they are surprisingly strong for their size, and macaques are notorious for being aggressive, so the risk of trauma alone is a major issue. Disease is another concern, and the big problem in this case is herpes B virus. This virus can be found in most healthy captive macaques and can cause fatal infection in people. The fact that it’s been reported that Darwin was prone to biting makes me cringe, since that’s a huge risk for herpes B transmission. Among the trial testimony was an email Ms. Nakhuda sent to a US primate trainer in November documenting her struggles. Among the problems was aggression that Darwin had towards her son and co-workers.
It’s bad enough that she’s exposing herself and her family (including her human chldren) to Darwin. Exposing people with whom she works (and perhaps people who work for her, and would have a hard time raising any concerns they had) is completely inappropriate, as is taking Darwin out in public (apparently "everywhere," including the gym, grocery store, and obviously Ikea). Ms. Nakhuda either doesn’t understand the issues or doesn’t care. Either way, it’s not good.
I don't doubt that Ms. Nakhuda cares for Darwin. However, as the primate sanctuary lawyer Kevin Toyne said "This is not about who loves Darwin the most." For me, it should be about protecting the best interests of the public and Darwin, neither of which would result in him being returned to his previous owner.
An abstract for the upcoming CSTE (Council of State and Territorial Epidemiologists) conference in California describes a rare but concerning case of Brucella canis infection in a child. All I have to go by is the abstract (since the meeting hasn’t happened yet and I won’t be there anyway), but it provides an interesting outline.
Brucella canis is a bacterium that is (not surprisingly, given the name) associated with dogs. It’s present in dogs internationally, with higher rates of infection in strays and shelter dogs. It can cause a variety of problems in dogs, most often abortion, stillbirth and birth of weak puppies, but also things like reproductive failure and genital inflammation in males, and diskospondylitis (a kind of back problem). After a dog gets infected, the bacterium can localize to genital tissues, where it tends to hang out, resulting in intermittent shedding of B. canis in urine, vaginal discharge, fetal fluids, semen and, to a lesser extent, some other tissues. Humans can then be exposed via contact with these fluids. The main risk to humans comes from handling breeding dogs, particularly female dogs that have aborted puppies. However, people seem to be relatively resistant to B. canis infection, and there are actually only a small number of reports of human infections with this bacterium.
The risk to average pet owners is very low, but as this report shows, low doesn’t mean zero. This abstract deals with an infection in a 3-year-old child from New York city. The family had acquired a Yorkshire terrier puppy from a local store in March 2012. As is expected, there was close contact between the child and the puppy.
Near the end of April, the child was taken to an emergency room because of fever and difficulty breathing. Bacterial infection wasn’t the main suspect and he was discharged without antibiotics (presumably having improved from how he was at the time of admission). However, a blood culture was collected and it came back positive for Brucella canis. While the boy had been doing well, he was treated with 45 days of antibiotics to try to make sure the bacterium was eliminated, since it can cause chronic problems.
In a step that’s too often overlooked in zoonotic disease occurrences, there was an investigation of the source. That’s not surprising since this is a rare and concerning bacterium, and it’s pretty clear that pet contact tracing is required. The puppy was healthy but the bacterium was isolated from its blood. Because of the test result, the puppy was euthanized. (There’s no mention of whether this was at the owner’s request or based on the recommendation of public health personnel.)
The source of the puppy was a major concern, since it’s important to make sure that there aren’t other infected puppies around. The puppy came from a "commercial breeding facility" in Iowa - yet another instance of the potential for widespread national and international distribution of pathogens from large commercial pet operations. The facility was quarantined but there’s no more information in the abstract about whether other positive animals were found, whether infected puppies may have been sent elsewhere in the country, and what measures were taken to correct the problem.
A littermate of the New York puppy was sold by the same store. It also tested positive for B. canis and was treated.
This is a rare incident, but it highlights some points for me:
- Large commercial breeding facilities for dogs are unnecessary and create increased risk of disease in animals and by extension people. Yes, this could occur with a small private breeder, but the more animals, the more risk of infectious disease, and the larger the facility, the larger the potential impact should a disease issue develop.
- Proper counseling of people whose pets are diagnosed with a zoonotic pathogen is needed. I don’t know the story at all about why the first puppy was euthanized, but it might have been avoidable. What to do with animals that are healthy but shedding potentially concerning pathogens is a tough area to address. That’s particularly true for a bug like B. canis, since it can be hard to eliminate.
- Good communication is needed between the medical field, public health, veterinary medicine and the public. It’s hard to say how smoothly this investigation actually went, but it shows a good response to a rare but potentially serious problem.
- People that sell animals need to keep accurate contact information from purchasers. It’s good to see that they were able to track down the owners of the original puppy's infected littermate. Contact tracing is important with infectious diseases and it can be exceedingly difficult at times.
- There’s an inherent risk in pet ownership. We know that and have to accept it. The child was high risk because of his age. That doesn’t mean we don’t let kids have pets, but we have to understand the risk and use some basic hygiene practices to reduce that risk. Would it have had any impact on this case? Who knows, but it never hurts to improve.
I’ve written about the African dwarf frog and Salmonella issue before, but it’s worth a recap since an overview of the 2008-2011 outbreak was recently published in the journal Pediatrics (Mettee Zarecki et al 2013). The fact that reptiles and amphibians can carry Salmonella is nothing new, nor is the fact that outbreaks of disease can occur in people who have contact with them. However, the scale of outbreaks associated with pets can be impressive.
Here are some highlights from the paper:
- Between January 1, 2008 and December 31, 2011, 376 people were diagnosed with salmonellosis caused by the outbreak strain, a type of Salmonella Typhimurium.
- As is common in pet-associated outbreaks, kids bore the brunt of this one. The mean age of infected individuals was 5 years, and 69% were children under the age of 10.
- Severe disease wasn’t uncommon - 29% of people were hospitalized, half of those being kids less than 5 years of age. Fortunately, no one died.
- During a preliminary study, when they compared people who got sick with a group of healthy controls, they found that people who reported exposure to any aquatic pet were almost 5 times as likely to have salmonellosis. When that was narrowed down to exposure to just frogs, the risk went up to 12.4 times higher than healthy controls.
- When they looked at people who were sick and reported exposure to frogs, only 27% reported having touched a frog, with 46% reporting having fed a frog, 59% having had contact with a frog’s habitat and 60% having had contact with water from a frog’s habitat. Twenty-three percent (23%) reported cleaning the frog’s habitat in the kitchen sink, and 35% in the bathroom sink. This tells us some very important information. It tells us that direct contact with frogs or their environment is a high risk behaviour. However, direct contact isn’t required to get sick. While the frog may stay in its habitat, Salmonella may not. Cleaning habitats in kitchen or bathroom sinks is a high risk activity, because it can result in contamination of common human-touch surfaces and items that go into peoples’ mouths (e.g. toothbrushes, cups).
- Often, disease occurred not long after a new frog was obtained. The median time from purchase of a frog to disease was 30 days (range 5-2310 days).
- Only 17% of people interviewed reported knowing that frogs can carry Salmonella. Over twice as many knew there was a risk from reptiles. This shows there needs to be more education of people who buy animals such as frogs. Pet stores should be required to provide some basic public health information. Pet owners should also take initiative and research potential new pets, including how to care for them and how to reduce the risk of zoonotic infection.
- The outbreak Salmonella strain was found in the environment of some patient homes (not surprisingly), an African dwarf frog vendor (potential source of infection), a large-scale African dwarf frog distributor (a great way to spread an outbreak across the continent) and a daycare centre (that never should have had an amphibian in the first place!).
- One breeding facility in California was the likely source. With centralized, large-scale breeding and warehouse-style distribution of pets (of various species, not just frogs), we’re seeing more large-scale outbreaks like this.
More information about African dwarf frogs can be found on the Worms & Germs Resources - Pets page.
Studies that look at risk factors can be pretty variable in terms of what they tell you, the impact they have and how accurate they are.
Some findings are pretty logical, clear and indicate something that should be done.
- Smoking is a risk factor for [insert many diseases here], so to reduce the risk of [whatever disease], stop smoking.
Others make sense but don’t necessarily lend themselves to an effective intervention.
- Being male is a risk factor for cardiovascular disease... not much I can do about that.
Sometimes, you have to remember that a risk factor for one thing doesn’t provide a clear answer when a broader context is considered.
- Moderate consumption of red wine can reduce the risk of various conditions, but alcohol consumption can also increase the risk of other conditions.
Sometimes, how the study is designed and performed can really affect the results.
- If I did a large study of the general population in Guelph, I could presumably show that going to a hospital greatly increases your risk of death. Does that mean you shouldn’t go to the hospital? No, because I could presumably also show that if you have chest pain and go to a hospital, you’re more likely to live. Knowing the study population and what question is really being asked are critical.
Sometimes, something that’s found to be a risk factor isn’t really the risk factor, but it’s associated with something else that is.
Sometimes, something can be "statistically significant," but of limited consequence.
- If doing something increases the risk significantly, but only by 0.0001%, does that mean anything?
Why do I write this? Because these are some of the things that we have to think about when assessing risk factor studies. While one Toronto radio station loves to give 10 second snippets on some new risk factor medical study, you can’t determine much about the study itself from a sound-bite (or internet post). You need to think about the details regarding how the study was done. Nevertheless, risk factor studies can provide useful information, but consider the results carefully, whether they are relevant, whether they indicate changes need to be made or whether they indicate that we need to look at the issue further.
The first study compared dogs from northern California that had or didn’t have leptospirosis. They found a few things:
- There were differences in geographic distribution of the lepto cases and controls. That makes sense since we know lepto varies regionally, but living in different areas might also be associated with different behaviours and contacts (e.g. wildlife contacts).
- There was a temporal cluster, with more cases occurring between May 2003 and May 2004, compared to the rest of the 2001-2010 study period. That makes sense too since we see variation in cases within and between years.
- These results don’t change anything, but are an indication of what work needs to be done next. Looking at why things vary geographically and temporally might be important for figuring out how to reduce the risk of disease. It also indicates regions where more efforts to educate pet owners (and veterinarians) are indicated, and where vaccination is more important.
The second study looked at dogs from Kansas and Nebraska, with and without leptospirosis. They also found a few risk factors.
- Lepto was more common in houses lacking complete plumbing facilities. Presumably, this is a proxy for something else. Poor plumbing doesn’t likely result in lepto in dogs. Rather, it presumably means that a dog living in a house with poor plumbing has some other factor that increases its risk. For example, incomplete plumbing may be more likely in lower socioeconomic (i.e. lower income) households, which might then correspond to other more direct risk factors for the dog (e.g. poorer nutrition, less veterinary care). It could also be that houses lacking complete plumbing tend to be in a different area where there’s more exposure to wildlife reservoirs. A couple of other indicators of poverty status were also significant, highlighting the potential impact of owner poverty on pet health.
- Dogs that lived within 2500 m of a university or college, or a park, were also at increased risk. The park risk factor makes sense since they could be exposed to sites infected by wildlife reservoirs (e.g. raccoons). Living close to a university or college is tougher to figure out. Maybe it’s associated with economy, as students are typically at lower income levels. Maybe it’s because colleges and universities usually have lots of green space that might harbor wildlife.
So, these studies tell us some new information, reinforce some previous knowledge (or perceptions) and raise some new questions that we need to answer. By themselves, they won’t result in major changes in how we try to prevent lepto in dogs, but little steps is typically how science progresses.
Horse show season is upon us, and with it comes the questions from concerned horse owners who want to protect their animals from the infectious diseases they may encounter at these events. In this case, the specific question is:
What protocol would go into place if a horse with a highly contagious disease such as EHV-1 were to be found at a competition in Canada?
The short answer (to the surprise of many) is that there is no pre-established nation-wide protocol for most equine disease outbreaks. Every outbreak is managed differently, based on the disease, the types of horses, where exposure might have occurred and a range of other factors. Typically, a disease like EHV isn't going to be noted during the show, since it takes some time for illness to develop after exposure. Therefore, the response is more of an investigation of what happened at the show, why and how it can be prevented in the future, and of course trying to prevent further transmission in the community (e.g. identifying exposed horses, communicating with people who have been to the show with recommendations to quarantine and test exposed horses and potentially all horses, surveillance for ongoing transmission from horses that have left the show).
With horses, there's no regulatory body with a mandate to oversee (and fund) this type of investigation unless it's a federally reportable disease like rabies (and even then, assistance may not be forthcoming). Some provinces have more authority and interest (e.g. the Animal Health Act in Ontario gives the province a mandate and powers to intervene) but often investigation is not a priority for regulatory bodies and it's left to whoever is around and interested. There are some good outbreak management guidelines from different institutions or groups (e.g. the ACVIM consensus statements on EHV and strangles) but there is no standard approach. Because testing costs are placed on the owners, responses can be quite variable since getting people to test when indicated can be a challenge. Additionally, getting people to follow quarantine recommendations is a challenge because of inability to effectively quarantine on their farm or unwillingness to do so (usually more the latter). So, each outbreak ends up being managed quite differently.
In general, the key points to outbreak investigation and management are:
- Identification of a problem
- Diagnosis of the problem
- Communication to let people know what's happening
- Identify potentially exposed and infected horses
- Quarantine, if appropriate (usually some form of quarantine is indicated, but not necessarily for all diseases)
- Develop testing recommendations
- Develop and communicate a plan to maximize compliance with quarantine and testing
- Create a way to centralize data collection and communications, so that a clear picture of what is happening is obtained
- Keep people in the loop as the investigation ensues to maximize compliance and decrease loss of compliance because of boredom or fatigue with the recommendations
As if horse owners and veterinarians in Queensland need another infectious disease challenge.....
Recently, a horse in southwest Queensland was diagnosed with Australian bat lyssavirus infection. This virus, which is similar to rabies, is present in some bats in Australia. It can be transmitted to people from bats, causing fatal disease, but human infections are very rare. Even though it's rare, it warrants attention because the disease is so severe.
Finding an infected horse is surprising in some ways, because the virus has never been detected in this species before. However, a virus that's present in bats can certainly find its way into a horse, and we already knew that a closely related virus (rabies) can infect horses. So, maybe it's not that surprising afterall.
In this case, the horse was suspected of being infected with Hendra virus initially. While Australian bat lyssavirus can kill people, this diagnosis was actually much better than Hendra virus infection, because horse-human transmission of Hendra is a major concern. Hendra virus infections have high fatality rates and, perhaps most importantly, there are no effective preventative measures that can be taken after Hendra virus exposure. Since Australian bat lyssavirus is so closely related to rabies virus, rabies post-exposure treatment can be used in this case (and is probably effective).
It's unclear whether an infected horse poses much risk to people. The very small number of human Australian bat lyssavirus cases have occured in people who were bitten or scratched by bats. Since this is the first equine case, it's not known if affected horses shed large amounts of (or any) virus. People who had contact with the horse were identified and offered post-exposure treatment. It's reasonable to consider this situation like rabies exposure in the absence of more evidence, and treat people who were bitten or otherwise may have gotten virus-contaminated saliva into their tissues via broken skin or mucous membranes.
Is this the start of yet another new problem?
Most likely, this is just an example of the rare scenario of a virus infecting an atypical host, not the start of a new, common problem. However, it's worthy of attention in case the virus has changed or there is now a specific virus type that can more easily infect horses (both very unlikely). This case also shows the importance of thorough diagnostic testing, particularly when an animal has severe disease.
If you don't look, you don't find.
If you don't find, you can't act.
I've been bitten lots of times, some on the job (including the last dog I saw when I was in general practice) and some off (including a dog down the road a couple of years ago). Fortunately, I haven't suffered any serious consequences. That's what happens most of the time. However, bad things can and do occur after bites.
A paper in BMJ Case Reports (Tumram et al 2012) describes a rather unusual and unfortunate situation. It's about a fatal infection in a 55-year-old Indian woman who was bitten by a mongoose. She was bitten (unprovoked, it seems) on the leg by the mongoose while washing dishes. She went to the hospital a couple of hours later because of pain and swelling in her leg. It's not clear what happened there, but she went back to hospital the next day, and then received antibiotics. However, that same day, she suffered cardiac arrest (a heart attack) and died a few days later. The bacterium Streptococcus pyogenes (Group A Streptococcus) was isolated from some lesions on her legs, leading to a suspicion that she developed a severe and rapidly progressive infection from the mongoose bite.
Various aspects of this case are unusual. Fatal bite infections occur, but they are rare. Involvement of streptococci is rarer still.
Why did this woman develop a fatal infection, especially when she sought prompt medical care? It's hard to say, and there is a "bad luck" component of infectious diseases. She had diabetes and high blood pressure, which probably increased her susceptibility to infection (but lots of other people who get bitten also have these conditions and suffer no consequences). It doesn't appear that she received antibiotics when she went to the hospital originally, but a bite over the leg isn't one that would always be treated prophylactically with antibiotics.
Why did the mongoose bite? That's another good question. Unless you're a snake, mongooses are typically not aggressive.
Where did the bacteria come from? We don't know much about the oral bacterial population of mongooses, but Streptococcus pyogenes is a human-associated bacterium. It's rarely found in animals and I suspect that the strep didn't come from the mongoose. Rather, it was probably already on the woman's skin and introduced into her body by the bite, or she contaminated the wound after being bitten. It's just a guess, and it doesn't change anything, but it makes sense.
This report shouldn't make people freak out over a bite. However, it should serve as a reminder that bad things can happen. More information about dealing with bites can be found on the Worms & Germs Resources - Pets page.
Image: Dwarf mongoose (Helogale parvula) in Korkeasaari zoo (photo credit: Miika Silfverberg, click image for source)
We've just posted a new info sheet about cat scratch disease (CSD), which is caused by a bacterium (Bartonella henselae) commonly carried in the bloodstream of healthy cats. Signs of CSD in people can be quite non-specific, so (as always) it's important to let your physician know if you've been bitten or scratched by a cat if you're feeling ill, so that CSD is considered. Other than proper training and handling of cats to avoid bites and scratches, the next most important component of CSD prevention is flea control.
You can read more about CSD and B. henselae on the new info sheet, which you can find along with all our other info sheets on the Worms & Germs Resources - Pets page. You can also read about CSD in the posts in our archives.
As someone who works with zoonotic diseases, I often find myself fighting battles on both sides of the issue. One side is trying to increase awareness about zoonotic diseases (i.e. those caused by microorganisms that are transmitted between animals and humans) and getting people to think about the potential role of animals in human infection. However, I often also have to deal with trying to keep things in perspective, and prevent people from over-reacting to disease risks. Part of this is helping people understand that disease transmission is typically a two-way street. While animal-to-human transmission is usually the greatest concern, human-to-animal transmission of a variety of bugs also occurs, and this can cause problems for the animals, and for people who subsequently have contact with those animals.
A recent paper in the journal Mycoses (Van Rooij et al 2013) highlights one such scenario. The paper describes ringworm in a dog that was associated with the fungus Trichophyton rubrum, which is not the typical ringworm species (Microsporum canis) that we find in dogs. Trichophyton rubrum is a common cause of infection in people, particularly tinea pedis (athlete’s foot) and onychomycosis (fungal infection of finger and toe nails). The authors did something that’s often lacking in reports of animal-human transmission: they actually tested both the person and the pet. Here, they found that the owner was a carrier of this fungus. They were able to isolate the fungus from his skin and determined that he likely had an asymptomatic infection that was subsequently transmitted to his dog. (He’d previously had untreated and self-resolving athlete’s foot, and presumably remained a carrier after that). Since this ringworm species is predominantly found in humans, it’s a reasonable assumption that it started with the person and the problem was only identified when the dog developed disease. In this case, the dog was old and had been treated with corticosteroids, both of which probably affected it’s immune system and made it more susceptible to this uncommon cause of canine disease.
It’s important to remember that while zoonoses are important, pathogens go both ways.
In the end, we’re all animals.
I have three kids that are all now (thankfully) past the diaper stage. I have no idea how many diapers I changed, but I don't have a huge desire to start doing it again, especially for chickens.
I understand the whole urban chicken concept. I don't actually have many issues with it if it's done right - but that's a big IF, unfortunately. Keep your chickens on your property, don't do it if you have young kids or other high risk individuals in the household, use good basic hygiene practices, feed them right, don't get roosters, and don't run screaming to the newspapers or local politicians if some get eaten by carnivorous urban wildlife. The nuisance and risk of backyard poultry can be limited.
Live chickens inside the house... that's another story.
Chickens aren't house pets in my world. I'm not sure if the chickens benefit at all from living in a house with people, and it's probably actually detrimental in many ways. I'm not sure what the benefit is to people either. Although I haven't seen any studies on this specific topic, it stands to reason that keeping a chicken indoors would be associated with a fairly high risk of widespread contamination of the household with bacteria like Salmonella and Campylobacter, two bugs that cause millions of infections in humans every year.
I'm all for risk mitigation, including using creative (and sometimes off-the-wall) measures - but diapers for chickens? Not so much.
Yet, Pampered Poultry makes diapers for your indoor chickens, and not just run-of-the-mill diapers: they're (allegedly) both functional and fashionable. This isn't the only company that sells chicken diapers either, much to my surprise.
One website states "Our chicken diapers are not just for the fashion obsessed hen. They offer your and your home protection against the inevitable! Our diapers fit comfortably and allow you to enjoy your birds in the house or car [car?] without worry."
Does using chicken diapers make sense?
I have a hard time believing these diapers are very useful. They probably do reduce the burden of pathogens that are deposited in the environment, but they are presumably far from 100% effective at containing all of a bird's droppings. It's also likely that chickens are contaminated with these bacteria on other parts of their bodies. Thinking you've eliminated the risk of household contamination from your pet poultry by using diapers isn't logical. The diapers also need to be changed (risk of more contamination) and disposed (don't we have enough waste already?) or washed (risk of cross-contaminating other items).
If you want fashionable chickens, go ahead and dress them up in diapers. Nothing says haute couture like a chicken walking around the living room in pink floral undies. Just don't convince yourself that you're reducing the infectious disease risk for other animals and people in the house. Better yet, let the chickens be chickens and keep them in a proper coop outside. I've seen too many indoor goats, pigs, miniature horses and other species with profound health problems from owners thinking they're just like people.
Apart from diapers, the store also sells "saddles" for the chickens. I'm not even going to start on that one.
I’ve received a lot of emails over the past 24 hours about the recent report of equine herpesvirus type 1 (EHV-1) neurological disease in an Ontario horse. The two main questions are whether there’s an outbreak and whether horse owners in Ontario should be concerned.
I don’t have any firsthand knowledge about this case (or any information beyond what’s been written elsewhere), but as far as I know, this is just a single sporadic case. That doesn’t mean an outbreak can’t occur, but most often, these just occur singly.
Whether there’s cause for concern is a tough question to answer. Yes, EHV-1 can be a serious problem, causing neurological disease in adult horses, abortion in pregnant mares, and severe disease in neonatal foals. Yet, at the same time, it’s an endemic disease that most often occurs as sporadic cases rather than large outbreaks (people just don’t hear about single cases as often, although they are now reported a lot more than they were a few years ago). The EHV-1 virus is very common and can be found in its dormant form in a large percentage of horses, so it’s not like some pathogens with which an unexposed population can suddenly be threatened when a single case is identified. In general I pay close attention to EHV-1 cases, but they are not a cause for panic. If a case occurs, we need to see if some broader issue is at play, and put steps in place to limit the problem, but we don’t need to cause massive disruption. In short, we want to ensure that good surveillance and infection control measures are in place, but not freak out in the process.
People have really taken a 180 degree turn in how they handle EHV-1 over the past 10 years or so. I don’t think we see EHV-1 neurological disease any more than when I was a resident. Back then, we saw sporadic cases and the odd small cluster, and people didn’t get too worked up about it in terms of the risk of transmission. Outbreaks, such as one I can remember associated with a large Ontario Standardbred yearling sale, certainly got lots of attention, but it was short-lived. Things changed (for good reason) based on some large, high-profile outbreaks in the last decade. It’s not known why such outbreaks now seem to be more common.
Anyway, if you live in Ontario and have a horse, don’t panic. Your horse is probably at no greater risk today than it was last month, assuming it wasn't in contact with the affected horse (which was diagnosed in early April). Virtually every horse is at some degree of EHV risk every day, but the odds of disease occurring are very low.
Some key prevention tips include:
- Use good general infection control practices to reduce exposure of horses to pathogens brought in by newly arrived horses.
- Observe your horses regularly and if there are any problems, isolate the horse and have a veterinarian examine it ASAP.
- When travelling to shows, races or other events, take measures to reduce direct and indirect contact between horses.
The first true confirmed canine influenza virus (CIV) was the H3N8 canine flu that evloved from H3N8 equine flu. That's the virus that spread to and amongst dogs in various parts of North America. The general consensus has been that only this strain should be called CIV, since it's been the only true dog-adapted influenza virus that's developed the ability to stay and circulate in the dog population.
More recently, another canine flu virus has emerged in dogs, this time a type H3N2 in Asia. H3N2 is a common human flu type, but birds are the ultimate reservoirs of all flu viruses, and based on the genetic relationship of H3N2 from dogs and birds, it's thought that this virus came to dogs from birds.
Anytime a new infectious disease is encountered, it's important to figure out who/what it can infect. When H3N8 CIV emerged, it was shown that even though it came from horses, it was no longer adapted to readily infect horses. So, knowing a virus' origin or typical infection trends can be useful but it doesn't necessarily tell you the whole story.
Cats and ferrets are susceptible to many different types of influenza viruses, and are good species to look at when figuring out if a virus can spread to other domestic animals. A study in the recent edition of Influenza and Other Respiratory Viruses (Kim et al, May 2013) looked at transmission of H3N2 CIV between dogs, cats and ferrets.
In that study, researchers infected dogs with CIV and kept them in close proximity to cats and ferrets, but without direct contact. They also infected cats and ferrets to see whether they could transmit the virus to other cats or ferrets.
Here are some highlights from the study:
- All directly infected animals developed some degree of illness, with cats and dogs typically developing sneezing, coughing, increased respiratory effort and nasal discharge, and ferrets only developing sneezing.
- Cats could become infected by being in proximity to both infected dogs or infected cats.
- Ferrets didn't get infected when exposed to infected dogs.
- Ferrets did not develop disease after exposure to an infected ferret but 2/3 developed antibodies against CIV, meaning the virus had been transmitted, but not able to cause disease.
- Cats shed higher amounts of virus than ferrets.
- Dogs stopped shedding the virus by day 8 after infection. That's not surprising since influenza shedding is short-term with H3N8 CIV. It shows that use of good infection control measures, particularly isolation, can be a key component of canine flu control.
- Dogs with H3N2 CIV are potential sources of infection for cats and ferrets.
- Cats that are exposed to the virus can get sick and be sources of infection for other animals, presumably including dogs. Cats may be another truly susceptible host for this virus.
- Ferrets seem pretty resistant to the virus. It probably takes fairly high level exposure for them to get infected and they are less likely to be of concern for subsequent transmission.
Interspecies transmission of flu viruses, and other viruses, is obviously an issue. Most of the attention is paid to the bird-pig-human cycle, for good reason. Birds are the reservoirs of all influenza virus variants, pigs are susceptible to both human and bird flu viruses and can act as a "mixing vessel," and humans are the species we're ultimately most concerned about. However, the potential for disease in pets and for pets to be reservoirs of influenza for people or other animals shouldn't be neglected. I've frequently had discussions with colleagues in the medical and public health fields about the need for parallel companion animal surveillance when plans are made for emerging infectious disease surveillance and response (e.g. SARS, H1N1 flu, novel coronavirus). They typically respond with general enthusiasm, but interest and application aren't the same, and actually getting plans in place to perform coordinated parallel surveillance hasn't happened. Studies like this are just one more piece in the puzzle that indicate the need for broader surveillance and consideration of pets.
Surprise, surprise - Meg has a hot spot.
"Hot spots" (aka focal bacterial pyoderma) are common skin infections in some dogs. Meg has underlying skin issues and lately has spent a lot of time wallowing around in ponds (because that's what she likes to do). With her skin issues, potentially weaker immune system because of her advanced age, and frequent wetness, she's a bacterial skin infection waiting to happen.
The latest hot spot is under her neck, and was evident by some colour change in the area (picture #1) and a bit of scratching, along with an odour if you get really close. These signs can easily be missed, especially early on, as the infected site is a bit hidden. Often, people only notice when it gets really wet and stinky, or when the dog scratches at it incessantly. Clipping the area revealed a more extensively affected area (picture #2) and a couple of focal spots with some pussy discharge. (It's quite amazing what can be hiding under an animal's fur!)
A hot spot is caused by a bacterial infection, and it's almost guaranteed that it's a staph infection (most likely Staphylococcus pseudintermedius). I took a swab from the affected area for culture. That's probably not critical in a case like this, especially when I'm going to treat it topically and without antibiotics, but since I can do it myself, it never hurts to have the information with regard to what bug is responsible (particularly if the infection comes back again).
The approach to treating hot spots is pretty straightforward, and owner compliance is key. Here's the plan:
Clip the area
- This helps identify the extent of the problem. It also (very importantly) helps keep the area dry and facilitates topical treatment.
Keep the animal from traumatizing the site
- That's been easy so far with Meg since she's not really scratching at it. If she was scratching, we'd need to put on an Elizabethan collar or use some other form of protection. In some cases, corticosteroid anti-inflammatories are needed to control the itch (and thereby the scratch).
Keep it dry
- Easier said than done. Despite being old and lazy, Meg is very motivated when it comes to lounging around in whatever water she can find (including the other night at 3:00 am... don't get me started on that one). Other than that, since the site is clipped now, keeping it dry is not a major problem.
- This is a bacterial infection, but the advantage of skin infections is that skin's on the outside. We can treat it topically and avoid using oral or injectable antibiotics. There are various things that can be done this way, usually involving bathing, wiping or spraying the area with topical antiseptics. We're using an antiseptic spray on Meg.
- Nothing major. It's unlikely that the cause is something zoonotic (and if it's MRSA, she presumably got it from someone in the family!). The staph that typically cause these infections are common inhabitants of canine skin. They rarely, if ever, cause infections in the absence of some inciting cause so Merlin (the other dog) and Finnegan (the cat) are unlikely to get an infection from Meg in this situation.
- A little handwashing goes a long way.
Hopefully I don't get to write about the massively increasing hot spot next week.
Cranimals Organic Pet Supplements has launched an at-home urinary test kit for dogs and cats that lets you "Monitor and track your pets health in an accurate and economical way, avoiding costly, unnecessary trips to the vet" (while not avoiding costly, unnecessary supplements, I assume).
The test claims to diagnose urinary tract infections (UTIs) by "detecting blood, leukocytes (AKA white blood cells) and nitrite in animal urine." Unfortunately, it cant.
- Blood in the urine does not necessarily mean there is an infection (i.e. this is a non-specific sign). In fact, a minority of cats with blood in their urine have an infection. They are much more likely have another problem like idiopathic cystitis that needs to be treated differently than an infection.
- Urine test strips for white blood cells are notoriously useless in animals. Maybe they have a better, more useful version, but I doubt it. The best way to detect these cells in the urine is to look for them using a microscope.
- Nitrite can be produced by bacteria in the urine but it has little to no diagnostic value in dogs and cats.
There's no mention about any specific evaluation of the test (i.e. they haven't checked to see if the test actually does what it's supposed to). By the look of the picture, it seems to simply be a urine dipstick in a fancy holder marked up a couple thousand percent to make money. Actually, it seems to be an inferior type of dipstick since it only tests for 3 things, two of which are useless.
Not surprisingly, the test is to be used in conjunction with their supplements (which probably explains why a supplement company decided to enter the diagnostic testing business).
The test isn't exactly cheap either: $39.95 for dogs and $49.95 for cats (the only difference to me being the cat kit comes with a bit of non-absorbent litter to put in the litterbox to collect urine, with a nice markup there too). While marketed as a way to save money on veterinary bills, think hard about what it will really do. Beyond potentially providing misleading information that could impact proper care, it will probably end up costing owners more:
- If the test is negative and the pet has urinary tract issues, it needs to be seen by a veterinarian to find out what's going on.
- If the test is positive, the pet needs to be seen by a veterinarian to get treated. No competent veterinarian is going to prescribe a treatment based on an at-home test like this. So, the full range of testing will be done anyway.
Ultimately, if the pet is sick, it needs to see a veterinarian. If it's not sick, there's no indication for testing like this.
If you want to know some real facts about diagnosing UTIs in dogs and cats, check out the International Society for Companion Animal Infectious Diseases Guidelines for diagnosis and management of UTIs in dogs and cats.
If you still think this test is worth the money, I've got some great oceanfront property in Saskatoon that I'll sell you (see photo). The water skiing is particularly good in January.
This is an increasingly common question, because MRSP is increasingly common. I've had two calls about it this week, and it's only Wednesday.
It's a good question to ask because MRSP (methicillin-resistant Staphylococcus pseudintermedius) is a highly drug-resistant bacterium that causes a lot of problems in dogs, and because of the high profile of its relatively distant relative, MRSA (methicillin-resistant Staphylococcus aureus), in people.
The short answer is: Yes, MRSP can infect people
BUT... (and it's a big and important but):
It's exceedingly rare and the overall risk is very low.
Here's my reasoning behind this answer:
1) Reports of MRSP infections in people are very rare.
- I think there are only two such published reports at the moment. There have probably been more infections than the number that are published, and there's the potential for MRSP to be misdiagnosed by some human diagnostic labs (meaning some MRSP infections may be mistaken for something else), but I think it's fair to sayl this a very rare infection in humans.
2) MRSP is not well adapted to infect people.
- MRSP is not inherently any more likely to cause infection than methicillin-susceptible strains of S. pseudintermedius (MSSP).
- MSSP can be found on basically every dog.
- A large percentage of the human population has contact with dogs every day.
- So, a large percentage of people encounter MSSP every day. Yet, reports of MSSP infection in people are very rare. To me, that indicates that this bacterium is poorly adapted to be a human pathogen.
3) Veterinary dermatologists are not extinct.
- MRSP is very common in dogs with skin infections. In some practices, it's the main cause of these infections.
- That means veterinary dermatologists encounter a lot of MRSP every day.
- I have yet to hear a report of a veterinary dermatologist getting an MRSP infection (carriers yes, disease no). I wouldn't be surprised if there actually have been some infections, but dermatologists can be considered the canaries in the mine when it comes to human MRSP risk, and I'm not aware of any real issues.
4) All dogs are biohazardous
- While this may not comfort the people calling me who are worried about the health of their families, it's important to put things into perspective. All dogs are carrying multiple microorganisms that could cause disease in people under the right circumstances (and the same goes for all cats, horses, people etc. for that matter).
- If you screened the average dog, you'd find things that are of greater concern that MRSP. In fact, MRSP probably barely cracks my "Top 10 List" of things I'm worried about the average dog spreading.
So, yes, there's a risk of MRSP infection when a person has contact with a dog infected with or carrying MRSP. There's also a risk of infection from methicillin-susceptible S. pseudintermedius, the version of the bug that basically all dogs carry, and a whole range of other bugs.
There will never be a zero-risk pet when it comes to zoonotic diseases. It's impossible. The risks may be very low but we can never eliminate all risk, just like we can never eliminate all risk from walking down the street. For some people, that slight degree of uncontrollable risk might be too much to handle, and they probably shouldn't own a pet. For most, the positive aspects of pet ownership outweigh the risks, and some basic hygiene practices (e.g. handwashing, avoiding licking, avoiding contact with the dog's mouth, nose and bum) can reduce that already low risk even further.
Merlin’s been a great dog so far, but despite that, there’s no need to propagate his genes. So, Monday was the big day… neuter time! As expected, since returning home he’s been feeling sorry for himself, but otherwise so far, so good.
Being someone who deals exclusively with infectious diseases and does surgical site infection (SSI) research, I have to think about his risk of developing an infection and how to prevent that.
Infection rates after neuters are very low. Actually, I can’t say that with confidence since we don’t have good data to back it up. We just finished one of the largest surgical site infection surveillance studies in dogs and cats, but being based at a tertiary care referral hospital, we didn’t get any data on neuters. I’m not aware of any private-practice-based studies that have assessed SSIs in dogs and cats, so my initial statement is just based on the fact that I don’t hear much about SSIs after neuters, and when I talk to people in primary care practices, they don’t report many of these infections. They occur, but they probably are truly rare.
However, rare doesn’t mean it will never happen, so pet owners need to be aware of what they can do to reduce the risk of post-operative infections (and then actually do it).
It’s been said in human medicine that the most critical time for preventing (or causing) SSIs begins and ends in the operating room. I think that’s true for animals as well, so there’s not much that the pet owner can do about that part except choose a good veterinarian, and not be afraid to ask pointed questions about the clinic's infection control measures. The pet owner’s major role is taking care of the animal after surgery. Here are a few things that I need to do for Merlin:
- Restrict his exercise for a few days. Trauma to the incision site will increase inflammation and the chance of an opportunistic infection developing.
- Keep him from swimming (or more accurately, wallowing in the swampy areas and ponds around home). Keeping the incision dry is important for good wound healing.
- Keep him from licking the wound. This a huge factor and one that people often mess up. Yes, he hates his Elizabethan collar (i.e. the head cone). However, it’s important that he wears it to keep him from damaging the incision site and seeding it with bacteria from his mouth. It’s a matter of short-term pain (annoyance, actually) for long-term gain.
- Keep an eye on the incision. A little inflammation (e.g. redness, swelling) is normal. If it increases or any discharge develops, that might indicate a developing infection. If that occurs, getting him re-evaluated ASAP is important.
- Make sure he goes in for his recheck, and that it’s done on time. This is important to detect problems in a timely fashion and to remove his sutures. (Merlin will presumably get his "recheck" at home, since the two DVM degrees Heather and I have hopefully give us the collective ability to remove a few stitches ourselves and determine if the incision is healing okay.)
None of this guarantees Merlin won’t get an infection, but these measures are all important. There is a non-preventable fraction of infections - meaning some will occur despite everything you do. However, a large percentage of SSIs are preventable and these basic practices can help.
While this morning's -7C temperature and snow don't exactly make me think about sandboxes or wandering around barefoot, warmer weather will presumably occur someday and the risk of outdoor exposure to parasites will start up again.
Since nothing says summer like hookworms, here's a new info sheet all about hookworms, including information on cutaneous larva migrans. The sheet can also be found on the Worms & Germs Resources - Pets page, along with info sheets on many other topics.
Business Mirror, a Philippine news website, had a recent article entitled "Rabies: deadlier than ever". That's a bit like saying Decapitation: now an even worse idea. Rabies isn't 'deadlier than ever,' since it's hard to get deadlier when the disease is already almost invariably fatal.
Anyway, beyond quibbling about the title, there are some interesting parts to the tragic story.
The article describes the death of a young boy. He was attacked by a dog while playing in his front yard in the Philippines. After the attack, he was taken to the hospital where, while he treated for some large scratches, he was not treated for rabies exposure because there were no bites.
This isn't too surprising, since it's an area in which there are some education gaps and misconceptions. The main risk for rabies transmission from dogs is from bites, since the virus is present in high levels in saliva, and bites directly inoculate saliva into the body. Rabies contaminated saliva deposited on intact skin isn't a risk. Rabies virus shouldn't be hanging out on a dogs paws, so it's easy to see how the transmission risk from scratches might be overlooked. However, during an attack, saliva contamination of the skin and a scratch that breaks the skin can both occur, thereby inoculating rabies virus into the body just like a bite.
Presumably that's what happened here, because 2 months after the attack, the boy developed rabies. It started with severe itchiness over the site of the scratch, and he was dead two days later.
We can't play around with rabies. If there's potential that an animal interaction led to rabies exposure:
- The animal must be identified and either euthanized so its brain can be tested, or (if a dog or cat) quarantined for 10 days to ensure that it does not exhibit any signs of rabies.
- If the animal can't be identified and quarantined or tested (or if it's positive for rabies), proper post-exposure treatment is required.
More information about rabies can be found on the Worms & Germs Resources - Pets page.
“Is MRSP zoonotic?” That’s a question I get all the time. MRSP (methicillin-resistant Staphylococcus pseudintermedius) is a canine staph (a bacterium) to which people are exposed all the time. Yes, it can infect people, but only very rarely, particularly when you consider how often they’re exposed. Nonetheless, human MRSP infections can occur.
My typical answer to the question is “Yes, but…” followed by an explanation of the overall low risk. My general line is:
- It can be transmitted to people.
- Human infections are very rare
- There’s no use panicking over MRSP or being draconian when you have an infected animal.
- At the same time, no one wants a highly resistant infection, so some basic measures should be used to reduce the risk of transmission.
Issues are also greater when people with compromised immune systems are involved, and a recent paper highlights this.
The paper (Savini et al, Journal of Clinical Microbiology 2013) describes MRSP infection in a 65-year-old man who was immunocompromised because of a bone marrow transplant. He developed a wound infection, and his physicians and the diagnostic lab did a pretty comprehensive study of the bacterium they isolated from the wound, ultimately determining it to be MRSP.
The man lived “close to a pet dog and farm cows," whatever that means. The dog was probably the source, but unfortunately (as is common) no efforts were made to see if the dog was carrying MRSP, to see if the cows were positive for MRSP (since this bug can rarely be found in cattle), or to type the isolate to see how it compares to strains that are typically found in animals.
Will this report change my answer to the first question? No. It gives me another example of a human MRSP infection, but such events are still exceedingly rare and this individual was highly immunocompromised, having graft-vs-host disease after his bone marrow transplant.
We don’t need to be afraid of MRSP, but we need to realize there is some risk, and the risk is presumably higher for certain people (e.g. very young, very old, people with compromised immune systems). We therefore need to use some basic infection control and hygiene practices to reduce the incidence of transmission of MRSP and other potentially harmful microorganisms from animals to people.
More information about MRSP can be found on the Worms & Germs Resources - Pets page.
Allegedly, spring is here. The foot of snow on the ground and minus double-digit temperatures don’t really convince me, but the calendar can't lie, I guess.
Anyway, spring brings with it many things, one of which is hatching chicks. I saw signs for them at a local farm supply store a couple of days ago, and perhaps not coincidentally, this week’s edition of CDC’s Morbidity and Mortality Weekly Reports provides an update on the 2012 human Salmonella outbreak that was linked to contact with chicks and ducklings from a single supplier.
This outbreak has been talked about before, but this report gives some final numbers.
- Ultimately, 195 people infected with the outbreak strain of Salmonella Infantis were identified. (That’s probably a major underestimation too, since in outbreaks like this lots of people get sick but don’t have fecal cultures for Salmonella performed.)
- 33% of affected individuals were children 10 years of age or less.
- 79% of people who got sick reported contact with poultry in the week before illness started.
- Birds were obtained from various feed stores or directly from hatcheries, and 87% of people that provided information about chick or duckling sources reported getting them from a single mail-order hatchery in Ohio.
Chicks and Salmonella go hand-in-hard. Chicks are high-risk for shedding the bacterium, and people can get infected by handling chicks or having contact with their environment. Children are at high risk for infection since they tend to have closer contact with chicks and because they are more susceptible to Salmonella. That’s why it’s recommended that kids less than 5 years of age not have contact with young poultry. Day cares and kindergartens planning on their annual hatching chick programs… please take note.
The article includes some more recommendations.
- Feed stores should use physical barriers (e.g., a wall or fence) between customers and poultry displays to prevent direct contact with poultry.
- Educational materials warning customers of and advising them on how to reduce the risk for Salmonella infection from live poultry should be distributed with all live poultry purchases
Part of the last point is keeping young kids away from chicks and stressing good hand hygiene practices. Like most things in infection control, a little common sense goes a long way.
Following outbreaks of campylobacteriosis in a Canberra, Australia nursing home, health officials have recommended banning puppies from aged care facilities. Two outbreaks that involved at least 15 people occurred in one such facility last year, and a healthy puppy was identified as the cause. Unlike many reports in which people try to blame an animal source without any evidence, they isolated Campylobacter jejuni from the puppy and people. That, along with ample previous evidence of a role of puppies in this disease, is pretty strong evidence that the puppy was the problem.
They concluded that puppies shouldn't be aged care companions because of "high rates of Campylobacter carriage and shedding, their social immaturity, susceptibility of elderly residents to infection and poor outcomes." Such a conclusion is not really that surprising or novel, actually. The 2008 international guidelines for animal visitation in hospitals recommend that only adult dogs and cats should be used for these activities, for several good reasons:
- Puppies are biohazardous. It's just biology. Young animals are at much greater risk of shedding various bacteria that can cause disease in people, such as Campylobacter.
- Contact with puppies and kittens has been clearly demonstrated as a risk factor for diseases like campylobacteriosis.
- Compared to adult animals, puppies and kittens are more likely to poop on the floor.
- Puppies and kittens are also more likely to nip or scratch through playful behaviour.
This is not to say that everyone should avoid puppies and kittens, after all they are cute and entertaining, and a great pet in many situations. The risk is higher in certain populations, such as people living in nursing homes, and while puppies are fun, similar positive impacts can be obtained by well-run visitation programs using older animals. That's the approach that being taken in Canberra, as trained adult dogs will still be allowed to visit aged care homes (hopefully as part of a structured program).
Today, we went to the University of Guelph's annual open house, College Royal. As per usual, we only covered a fraction of the events, but had to do the traditional visits with the animals and get some of the Food Science milkshakes (even thought it was -2C outside). Animals are a big part of College Royal. In most cases, you can look but not touch (e.g. Old MacDonald's barn, livestock shows), but there is a petting zoo.
The petting zoo has evolved a lot over the years. I was in charge of it for a couple of years when I was a veterinary student, but what we do now is very different from what we did then (in the mid 1990s).
- We've stopped using certain kinds of animals. Most notably, the calves (i.e. baby cows) are gone, since they're considered high risk for transmitting a few important microorganisms. The thing that triggered that was the year we decided to test fecal samples from the calves and found out (not too surprisingly, really) that all of them were shedding Cryptosporidium.
- We've changed the location, for a few reasons. The old location was in a ward in the large animal hospital, which therefore had the potential to impact patient care. The current setup is outside of patient care areas, and makes it easier to contain activities and visitors, and to organize overall.
- Signage has been improved. We used to have many signs, but they mainly provided just basic information about the animals (e.g. "Hi, my name's Betsy. I'm a Holstein cow.") I don't remember having many signs (if any) about hand washing, no food or drink, and other public health measures, but thankfully they do now.
- Hand hygiene is a priority. We didn't really do anything in terms of promoting hand hygiene at the event in the 1990s. Now, we have multiple hand hygiene stations, signs to tell people to wash their hands, people reminding visitors to wash their hands, and a structured flow of traffic through the petting zoo that leads people out past the hand hygiene stations.
Big changes, and for the better.
Has anyone ever gotten sick from the College Royal Petting Zoo? Not that I know of, but it's certainly possible.
Have we eliminated all risk? No. That's not possible. What we try to do is to reduce it as much as we can.
Are all petting zoos like this? Unfortunately no, they are not. Things at other petting zoos are much better overall than they were even five years ago, but there's still lots of room for improvement and still an unnecessarily high risk of infectious diseases.
A lawsuit filed recently in North Carolina highlights some of the issues around petting zoos. The suit was filed in response to a 2011 E. coli outbreak associated with the NC State Fair that sickened more than 100 visitors and killed a two-year-old boy. Among the claims in the suit are:
- animal areas were cleaned in such a manner that E. coli was spread around
- eating and drinking were encouraged in the animal area (presumably, the actual issue is that eating and drinking were not prohibited. I doubt the fair said "please eat and drink in this area")
- there were inadequate hand hygiene stations
- they failed to follow the State Fair's own guidelines
If these claims are true, that's a pretty big "oops" and someone is probably going to be writing a very large cheque.
On a similar note, a UK petting farm was recently found liable for a 2009 E. coli outbreak that sickened 93 people.
Petting zoo design and operation aren't foolproof, but it's not rocket science either - it's largely common sense. There are clear guidelines covering the basics, and adhering to them should greatly reduce any risk of illness or injury. Failing to do so leads to trouble, of both the infectious disease and legal kind.
I write a lot about reptiles, and while it's usually in the context of their biohazardous nature, I actually like them. I've owned some before and it's not outside of the realm of possibility that we'll get more in the future (I might be safe with that statement since Heather doesn't read this blog. However, her co-workers that do will likely rat me out).
Reptiles can be good pets in some situations. The key is understanding and accepting the risk. That involves understanding the risks associated with reptiles, understanding the types of households where the risk is high, and knowing what to do to reduce the risk.
Denial isn't an effective infection control measure.
- Uh...no. Reptiles are clearly higher risk when it comes to Salmonella. Reptile contact has been clearly and repeatedly shown to be a risk factor for human salmonellosis. Dogs and cats (and various other animals) are potential sources of salmonellosis, but while many more people have contact with dogs and cats, reptile contact is much more likely to result in Salmonella transmission. It only makes sense. Reptiles are at very high risk for shedding the bacterium. Dogs and cats rarely do (especially when they're not fed raw meat).
"She’s never seen a case in the 30-plus years she’s been working with reptiles."
- Ok. So, since I've never actually seen influenza virus, I'll never get the flu?
- I know a lot of infectious disease physicians who have had a very different experience. In fact, it's rare for me to talk to an infectious diseases physician without him/her providing details of various reptile-associated salmonellosis cases.
Talking about the risk of Salmonella shouldn't be taken as insulting or a threat to reptile enthusiasts. People should accept that the risk is present and try to minimize it. The article actually has some useful information along those line. "Just use common sense - wash hands thoroughly after handling the animal or its cage. A good rule of thumb is to keep hand sanitizer nearby. While children under age 5 should avoid any contact with reptiles, Hart doesn’t advise snakes for children under age 7 or 8 for fear they could unwittingly harm the creature."
Reducing the risk is common sense. Keep reptiles out of high risk environments and use basic hygiene and infection control practices.
However, any semblance of common sense goes out the door when a rescue like this offers programs where you can pay them to bring reptiles to daycares, pre-schools and grade schools. So much for young kids avoiding contact with reptiles.
Reptiles aren't bad, they're just bad in certain situations. Common sense needs to be more common.
Lately there has been a run of pet treat recalls due to Salmonella contamination (with the latest one courtesy of "Diggin' Your Dog"), but it shouldn't come as much of a surprise. Salmonella contamination of raw animal-based pet treats has been reported for years. It's not just a risk to dogs, since outbreaks of salmonellosis in people from handling treats have also been reported. Despite some good moves by the industry to improve the situation (e.g. better manufacturing practices, more products being irradiated), treats still need to be considered high-risk for being contaminated with Salmonella and other bacteria.
So, what can be done to reduce the risk?
- Buy individually wrapped or pre-packaged treats. Treats from bulk bins are higher risk because one contaminated item can cross-contaminate many others. Also, bins are often continually topped up without cleaning or disinfection so contamination can persist.
- Choose products that have been irradiated. There are still some baseless fears about irradiation, but there is absolutely no evidence that irradiation of food is harmful and it can effectively kill pathogenic microorganisms.
- Avoid feeding raw animal-based treats that have not been irradiated to animals at higher risk of becoming sick or having a serious infection. This includes elderly animals, puppies, pregnant and nursing dogs, dogs that are immunocompromised (e.g. undergoing chemotherapy) or dogs that have chronic intestinal disease. Also, they should not be fed to dogs that have contact with high risk people, such as those that live in households with infants, elderly individuals, pregnant women or immunocompromised individuals. Also, they shouldn't be fed to dogs that visit human hospitals. One study showed that dogs fed raw animal-based treats had a 12-times greater likelihood of shedding Salmonella (Lefebvre et al 2008).
- Wash your hands after handing pet treats.
If in doubt, or if your dog or family fits into one of those high risk groups, stick with processed treats that have been cooked or make your own cooked treats.
Some people like to send me links to internet sites to see if they can get a rise out of me. There are a few usual suspects (both senders of information and places I get sent to) but a new one for me was tlcpetfood.com
For some reason, this site has a series of FAQ's completely unrelated to pet food. Some are rather bizarre, such as "My dog keeps getting pneumonia, and we just found out her internal organs are on the wrong side. Help? "
Many of the answers are fine. That's because they're plagiarized... verbatim text taken from reputable sites (mainly AAHA's Healthy Pet site) without attribution. Besides the whole violation of intellectual property aspect, it's at least good that the advice is sound.
Some of the other answers they provide (likely the ones that aren't plagiarized) are considerably less sound.
The one that got sent to me was "Is it okay for my dog to lick my son's face?"
This is actually a common question and a reasonable one. There's no perfect answer to it, but there are definitely some imperfect answers, such as this one:
(It starts out okay...)
Yes, it probably is.
- I'd agree with that statement.
(Then goes downhill quickly...)
The only disease that dogs and humans can pass back and forth through saliva is beta strep throat, which is relatively rare.
- This is a myth that just won't go away. There's no evidence that pets are relevant sources of strep throat. Furthermore, there are many other pathogens that can be transmitted from dogs' saliva to people. Disease isn't common but it does occur and it can be fatal in some situations.
And if your son has a weakened immune system, you may want to be careful about exposing him to the normal bacteria that's present in the saliva of healthy dogs.
- Good advice. (However, if their statement that strep is the only thing that can come from dogs was actually true, this one wouldn't make any sense.)
My response to this common question is that I don't particularly like being licked by my dog. It's a personal thing and not a germaphobic response. It's unlikely to harm me as an adult with a (hopefully) functional immune system. I don't hover around my kid to make sure they don't get licked, but I don't encourage it either.
Licks to young kids (especially around the face), licks that have contact with skin lesions or mucous membranes (e.g. mouth, nose) or licks to people with compromised immune systems (including people that do not have a functioning spleen) are higher risk. Strep throat isn't a concern, but many other things are. There's a cost-benefit. If it's an important part of someone's bond with his/her animal, that's fine. Individuals just need to understand the risks, and be aware of when the risks are higher. Part of that is getting good advice, which can be a challenge on the internet.
Don't get me wrong. I'm all for pet therapy and animal visitation in hospitals - when it's done logically. I've been involved in research in the area, helped develop international guidelines and am chair of the medical advisory board of one of the largest pet therapy groups in the US. Animals can do great things in hospitals and we need to support good visitation programs. But that doesn't mean I check my brain at the door and think that all animals in all hospital situations are a good idea.
A colleague sent me a link to a Medscape News article entitled Woof! Does Fido Belong in the Hospital Delivery Room?
- My first thought was... not a chance. (My second, third and fourth thoughts were no better.)
The situation in the article isn't that clear cut though, since the English woman who wanted her dog in the delivery room had a trained therapy dog that helped her with an anxiety disorder. So, if this was truly a trained therapy dog (some people unfortunately make that claim just as an excuse to take their dog everywhere, and compromise people that truly need these animals), it would be justifiable since this is a service dog, not a companion, and we need to support access of service dogs.
However, it raises questions about whether this will open the door to requests for pets to join in the birthing process, now that we've moved from the era when dad paced outside the room to a time when half the family may be present, live-streaming the event to the internet and posting on Twitter.
What are some issues here?
A delivery room is a busy environment. Things can be nice and happy and relaxed. There can also be yelling (personal experience there), lots of activity and other things that might scare or upset the dog. I'm not worried about the dog's feelings here, but what a startled or upset dog might do (e.g jump, bark, bite, pee, try to run away).
Not all deliveries are smooth and things can go from good to bad quickly. The last thing that's needed is another distraction (e.g. the aforementioned dog jumping, growling, barking, peeing, etc.) when medical personnel are dealing with a life-threatening delivery complication.
A newborn is a high risk person for infectious diseases. Every dog is shedding multiple microorganisms that can cause disease. Usually, the risk is low. However, when you have a highly susceptible person (or persons, including the mother here to a lesser degree since post-partum infections are a concern), we don't want them exposed to pathogenic bacteria if we can avoid it. Yes, it's an ever-present risk in a hospital, but why add to the potential risks? It would seem illogical to have delivery personnel in full protective gear (e.g. gowns and gloves) with a dog potentially aerosolizing bacteria nearby through breathing, coughing, barking, shaking, and tail-wagging. People would also likely contaminate their hands often by touching the dog. Yes, medical staff can be to told to avoid contact with the animal and wash their hands, but we know from previous research that hand hygiene by medical personnel after animal contact is very (very!) uncommon.
Also, we know that a baby's first bacterial encounters have a major impact on its developing bacterial microbiome (that is, the composition of normal bacterial populations at various body sites, something that's important for good health and development). Babies born by C-section have much different microbiomes for a long period of time compared to those born by vaginal delivery. Do we really want to confuse the picture more by having some of the first bacteria encountered being Fido's bacterial flora? It's not going to make the baby start barking, but I'd rather the baby not be exposed to various bacteria from a dog seconds after it's born.
In my opinion, visitation is more important the longer the person is in hospital, the more lonely they are and the more upsetting or depressing the situation is. Delivery is typically a short-term, happy hospital stay. What's the real benefit here for your average dog owner?
Personal pets in any hospital situation is a controversial area. Unlike dogs that are part of proper visitation programs, these dogs tend not to have any health screening, behaviour screening or other type of assessment. There's also no handler training. You might say "well, the dog's just visiting its owner so that's not a big deal." However, the dog has to go from the parking lot to the room and back again. What are the odds that the dog's not going to encounter lots of other people in the process, let alone potentially distracting or scary situations. Do you want your elderly immunocompromised relative to ride (or be stuck in!) a hospital elevator with an aggressive or otherwise high risk dog? Or to have you child that just had surgery step on a pile of dog poop? There are clear screening, training and supervision criteria for hospital visitation dogs, and they are there for a reason.
Back to the article. Dr. Arthur Kaplan, the author, sums things up nicely:
"I think there are risks, and I think the risks are pretty significant. I am not sure that we should open the door to every barnyard creature we could think of to be present at birth, even when the mom-to-be says that she would like to have her pet there. But at the same time, I think there are arguments that, for some people, such as the woman in England who has a special relationship with her pet, or perhaps a woman who is blind, a case can be made."
In Canada (like most places), there's no semblance of a formal surveillance program for infectious diseases of companion animals. We're left with anecdotes and whatever short-term research projects we can put together to try to figure out what's happening in our companion animal populations. Not ideal, but better than nothing.
Over the past month or two, I've been hearing more rumblings about canine parvovirus infections in dogs in Ontario. Nothing too dramatic, just a spike in calls and emails about cases, mainly typical parvo cases (e.g. disease in young and un- or inadequately-vaccinated puppies, outbreaks in groups like shelters and breeding kennels) with some cases that seem more severe and some in dogs that seem to have appropriate vaccination history or in older dogs. It doesn't seem to be due to a focal outbreak, since these may be occurring in a few different regions in Ontario. This type of anecdotal information is far from definitive but enough to start asking questions.
I'm not the only one who's been hearing this. The Ontario Veterinary Medical Association has had enquiries and has been receiving more information from Ontario vets, so they have put out a press release indicating that something might be going on with regard to parvovirus in the province, and emphasizing the need for proper vaccination and preventive medical care for dogs.
So is something happening in Ontario? I'm still not sure. Sometimes situations like these are just because people are talking and we're hearing more about little clusters that go on all the time under the radar. However, this could be real and caused by a variety of factors such as decreasing vaccination rates, increased parvovirus circulation in some regions or a change in parvovirus strains.
The only way to truly figure out what's happening is to get more data. That's not an easy proposition since surveillance networks aren't established and there's no money to do any disease surveillance like this. However, Ontario veterinarians who are seeing parvo cases can feel free to provide more info and to send samples for typing.
A call to arms from guest blogger and University of Guelph professor, Dr. John Prescott:
Watching the global emergence and spread of multi-drug resistant bacteria is like seeing a train wreck in slow motion. There’s a sense of both inexorability and powerlessness. In the March 2013 issue of the Equine Veterinary Journal, Mark Bowen of the School of Veterinary Medicine and Science, University of Nottingham, writes that there is clear evidence of the need for change in our relationship with antimicrobials. Change is what many bacteria do for a living; of course the problem is not that bacteria change to resistance, but also that people are so resistant to change.
The excellent editorial (“Antimicrobial stewardship: Time for change”) describes the sensible steps taken by the British Equine Veterinary Association (BEVA) in 2012 to promote the stewardship of antimicrobial drugs in horses. These steps are summarized on the BEVA website: http://www.beva.org.uk/useful-info/Vets/Guidance/AMR. They provide an excellent approach to stewardship of antimicrobials in horses. BEVA has developed neat and simple promotional material to help equine veterinarians using these drugs do their part to help preserve them.
The BEVA project is summarized by the acronym PROTECT ME, which encompasses 9 steps to promote stewardship. PROTECT comes from for Practice policy; Reduce prophylaxis; Other options; Types of drugs and bacteria; Culture and sensitivity; Treat effectively, and ME come from Monitor and Educate. The brilliance and perhaps even contrariness of the BEVA approach is that it believes that policies should be created at the local level, and should be both dynamic and follow simple key concepts, rather than be national guidelines developed by people working in ivory towers.
The BEVA website provides the templates and forms for equine practitioners everywhere to develop simple and local policies that commit to stewardship. An important element in the PROTECT ME documents is to try to protect the drugs classified by the World Health Organization as the “Critically Important Antimicrobials” (3rd and 4th generation cephalosporins, fluoroquinolones). These drugs are categorized as “protected”. Drugs such as vancomycin and imipenem are categorized as “avoided”. The PROTECT ME approach promotes the use of “first line” antimicrobials as first choice for treatment of common conditions as part of the practice policy, and link this to the British “cascade” approach to antimicrobial drug choice. The BEVA approach is refreshing because it takes an intelligent, long-term approach that embraces the responsibility that users share to preserve the miracle while our scientists work feverishly to develop the next generation of antimicrobials. These are however going to be extremely expensive and perhaps also unavailable for animal use, except perhaps through the black market.
The antimicrobial “miracle drugs” revolutionized medicine and came into widespread use long before there was any science behind their optimal use. We’re still discovering how best to use them but we need to continue to develop strategies and approaches that optimize their use and minimize resistance and other side effects. The easily followed BEVA approach encourages user engagement with and responsibility for stewardship. Change is painful, but we have no choice. Let’s embrace it.
I tend not to write about recalls but the recent, large and expanding pet treat recall has lead to a lot of questions that are worth discussing. At last report, treats manufactured by Kasel Associates Industries Inc from April 20-Sept 19, 2012 were potentially contaminated with Salmonella and recalled. Not surprisingly, most of the recalled treats are things like pig ears, bully sticks and jerky strips made from raw animal products. The impact on pets isn't clear beyond a vague statement about "a small number of complaints of illness in dogs who were exposed to the treats." Anyway, here are some common questions I've been hearing:
My dog ate a recalled treat, will it get sick? Maybe, but probably not. It's not clear how many treats were really contaminated, so it's quite possible that most products weren't contaminated. Furthermore, the dose of Salmonella that a dog ingests is important. Low-level contamination is less of a concern, particularly in otherwise healthy dogs. The strain of Salmonella itself also plays a role since some strains seem to cause more serious disease or cause disease at lower doses than others. I haven't seen much information about the strain (or strains) involved here.
If my dog gets sick, what will happen? That's highly variable. Salmonella can cause disease ranging from vague (e.g. a little depressed and decreased appetite) to classical intestinal disease (e.g. diarrhea +/- vomiting) to rare but severe systemic disease (e.g. sudden death, bloodstream infection with subsequent overwhelming body-wide infection or focal infection of different body sites like joints).
Should my dog be tested for Salmonella? Not if it's healthy. The main question is what would be done with the result. If positive, it wouldn't mean that anything needs to be done or even that disease is likely to occur. A negative isn't very helpful either since a single sample is far from 100% sensitive. The key point is that we treat disease, not culture results. If the dog looks healthy, it's not going to be treated, regardless of the culture result. You'd also need to have the isolate tested to see if it's the same as the strain in the recalled treats if you wanted to determine whether treats were the source, and that testing is not readily available.
Should my dog be treated with antibiotics? As you can guess from the paragraph above - no. There's no evidence that antibiotic treatment of an exposed dog or a healthy carrier reduces the risk of disease or shortens the shedding time. In fact, it might even make things worse by disrupting the normal protective intestinal bacterial population, which might make disease more likely or make it harder for the body to eliminate Salmonella. Treatment might also encourage development of antibiotic resistance, something we don't need any more of with Salmonella.
What can I do to reduce the risk of disease? Not much. If a dog has eaten a Salmonella-contaminated treat, there's not really anything that can be done after the fact beyond watching for signs of disease.
So... what should I do? Relax and watch. The odds of a problem are low. If a problem develops, odds are it will be mild. That's not to say that severe disease can't or won't happen, it's just that it's unlikely and there's nothing that you can do after exposure anyway. Identifying signs consistent with early disease (e.g. lethargy, decreased appetite, diarrhea) and getting prompt veterinary care should help reduce the risk of complications or serious disease.
A proposed Florida bill would require shelter operators to produce monthly and annual euthanasia reports. The reported goal of the effort is to "reduce euthanasia of unwanted animals." But how? The idea has various pros and cons.
Potential good points
More transparency: Euthanasia rates are often considered the "dirty secret" of the shelter world. In reality, it's not the shelters' fault that animals are being euthanized. It's society's fault because of overpopulation. Shelters should be reporting these numbers (and ensuring they are accurate), not as part of a "we kill fewer than you do" competition, but to highlight the challenges, increase public awareness and to work toward improving the shelter system.
More data: The more we understand the epidemiology of adoption, euthanasia, disease and other events in shelters, the better. Knowledge helps us figure out better ways to run things.
Potential bad points
Animal welfare: Will shelters resist euthanizing sick or injured animals that would otherwise be euthanized to keep their rates lower? If an animal is very sick, will there be the temptation to let it die rather than euthanize it, if deaths are not reportable but euthanasias are?
Overpopulation in shelters: If shelters try to avoid euthanising animals because the rates are reportable, there will be more animals in the shelters - likely more than they can actually handle. More animals in a shelter does not mean more adoptions. Overcrowding leads to many problems such as increased disease risk, deceased quality of care, decreased human contact and increased shelter operation costs.
Outbreak potential: Yet another issue related to overcrowding is when you cram in as many animals as possible (often using carriers and other temporary housing stashed anywhere there's spare space) and decrease the time you spend with each animal, you create great potential for a disease outbreak. The more animals are present, the more likely the outbreak will take hold and the harder it will be to control.
Needless transfers: Will shelters try to transfer animals that are unadoptable to areas where this law is not in effect, simply to be euthanized outside of the recording system? Beyond the humane aspects of putting the animal through the stress of a transfer for no real reason, shipping shelter animals is notoriously high risk for shipping diseases along with them.
Cherry-picking: This already happens with some shelters, but one way to keep euthanasia rates low is to refuse to admit animals that are not likely to be adopted. Turning them away doesn't help the animal or society (and may result in more animal suffering, among other things, if the animals are simply abandoned), but it keeps euthanasia numbers low.
Will this work?
Shelters don't euthanize for fun. They do it because there is a finite number of homes available and the number of animals coming into shelters (especially cats) is way beyond that. This bill will not magically create millions of new homes for shelter animals. So, how will it "reduce euthanasia of unwanted animals"?
A representative of a group working to reduce shelter euthanasias added "We do not believe that it is the conscious will of the people of the state of Florida to kill over 50% of the lost and homeless shelter pets each year." It's not their conscious will but what can/will they do about it? Euthanasia numbers might help spur interest in adopting from shelters, and if so, that would be great. But the fact is that if 50% of animals in shelters are being euthanized, it's because they don't have homes.
Probably a well-intentioned but poorly thought-out approach to the pet overpopulation problem.
It's not hard to find news articles about animal bites. That's because they are very common, sometimes incite controversy (e.g. to euthanize the offending animal or not) and occasionally cause severe injury or death.
Here's a sampling of some recent reports:
- The University of Arizona Medical Center is reporting a steady increase in dog bites, with an almost doubling of bite numbers between 2008 and 2012. Three-hundred and twenty-eight (328) people were admitted with bites last year, including both children and adults. Most were bitten on the hands and fingers, and most were bitten by their own dogs. There were no deaths reported in 2012, but there was one in 2011, a man that was bitten in the neck and arm by his own pit bull cross.
- Sixty-three dog bite deaths were reported in Mumbai, India, over the past 5 years, out of a total of at least 90 000 people who are bitten annually.
- A Stoney Creek, Ontario mother is lobbying to have her neighbour's two German shepherds euthanized after they attached her 10-year-old son. The dogs were on leashes and being held by a friend of the owner's 14-year-old son when "The dogs became startled" and the boy was bitten on the arm and face. The dogs' owner argues that only one dog was involved, but figuring that out will be next to impossible. This raises a few different issues. One is the fact that a child, and not even a child of the owner, was responsible for the control of two large dogs in a public place. Another is what lead to the bite. The owner accuses the boy of taunting the dogs in the past, but even if that were true, previous taunting (what did he do? accuse the dogs of having a chihuahua for a mother?) isn't an excuse for biting.
While we often focus on dog bites, pretty much any animal with a mouth can bite. Records from a New South Wales, Australia, ambulance service reveal some more unusual calls for help in response to animal interactions. These include:
- A call because of a "deep bite on the hand" with "serious bleeding" after a woman was bitten by a Guinea pig. They were also called for a Guinea pig bite to a 4-year-old boy. The fact that Guinea pigs would bite isn't surprising, but the fact that the bite would lead to an ambulance call is.
- A call for a cat bite that severed an unnamed artery of an 80-year-old man. Hopefully it was a small artery.
- While not a bite (although cattle can bite), ambulances were called when a cow hit a 83-year-old man in the stomach, lifting him 3 feet in the air, and when a water buffalo tossed another man.
- Other animal associated calls included incidents caused by critters including a blue-ringed octopus, a catfish (would love to have the story about that one) and a goanna (a type of Australian monitor lizard - had to look that one up).
- And (not surprisingly, for Australia) there were shark bites, including a spear fisher who was "nudged" by a grey nurse shark attracted to the fish he had caught, and a more serious attack by a bull shark that resulted in loss of a finger and a serious leg laceration.
- Snake and spider bites weren't even listed in the report for some reason.
Understanding why bites occur is important to preventing them, and it's different in different areas. In North America, where most dog bites are from family pets, better training of the dog and people in the household is critical. In a place like Mumbai, where there are tens of thousands of stray dogs living in close confines with people and where many bites are from strays, a different approach is needed. Bites from pocket pets usually result from improper handling or trying to break up a fight. Shark bites are also another story. Ultimately, a lot of prevention is common sense, which unfortunately is not always that common.
I'm just back from vacation (luckily, with no infectious disease stories to write), but now I have to catch up on a few posts. One easy one that was waiting for me in my inbox was about Salmonella and hedgehogs.
I've written before about biohazardous hedgehogs, and more details about the US 2011-2013 multi-state Salmonella outbreak were reported in a recent edition of CDC's Morbidity and Mortality Weekly Reports. The outbreak was identified through recognition of a cluster of infections in people caused by the same, historically rare strain of Salmonella Typhimurium. Finding a cluster of the same strain, especially a rare one, suggests that there might be a common source, so an investigation ensued. Here are some highlights:
- Twenty people from 8 states (Alabama, Illinois, Indiana, Michigan, Minnesota, Ohio, Oregon and Washington) were affected, although (as is typical) it's almost guaranteed that many more people were affected but not tested.
- Young people were more often affected, with the average age being 13. The age range spanned from less than 1 year to 91 years of age.
- Four people were hospitalized and one died.
- 14/15 (93%) people interviewed reported direct or indirect contact with a hedgehog. That's a pretty strong indication that hedgehogs might be involved, since that number is wildly disproportionate to the percentage of people in the general population that have contact with hedgehogs.
- Hedgehogs were obtained from various breeders, not from a single source.That's not uncommon since breeders often get animals from other breeders or suppliers and a point-source of infection further up the supply chain is likely.
For some reason, hedgehogs are high risk pets when it comes to Salmonella. High Salmonella shedding rates have been identified in studies of healthy hedgehogs and it's clear that contact with healthy carriers can lead to human infection. Hedgehogs should be considered alongside reptiles in terms of pets that should not be present in high risk households (households with kids less than 5 years of age, elderly individuals, pregnant women or people with compromised immune systems). Hedgehog owners should take care to avoid direct and indirect contact with feces and use good hygiene practices to reduce the risk of infection.
It's been quite a while since the last post about MRSA in horses, but rest assured, it's still out there! Not too surprisingly it's also spreading (or at least starting to be found) in new places. A recent report in Veterinary Microbiology (Schwaber et al, 2013) describes an MRSA outbreak at a large animal teaching hospital in Israel. It is the first report of MRSA colonization in horses in the Middle East, although it's possible (and quite likely) that there's more to be found.
The discovery of the problem had a pretty typical progression: there were two horses in the hospital with post-operative wound infections from which Staphylococcus aureus was cultured, and the isolates from both horses had similar antimicrobial resistance patterns, including resistance to all beta-lactam antimicrobials (= MRSA). Validly concerned about the potential for the MRSA to spread among horses and people in the hospital, an investigation ensued - in this case the National Center for Infection Control (NCIC) was actually called in to coordinate the operation.
- They found MRSA in 12/84 (14.3%) horses, of which 11 were in the hospital at the time of sampling, and 1 had recently been discharged from the hospital. Consider though that 44 of the horses sampled were simply from farms from which an MRSA-positive horse had come - so 11/40 horses in the hospital were positive - that's 27.5%!
- 16/139 (11.5%) of personnel at the teaching hospital were positive for MRSA. Fortunately there were no clinical MRSA infections reported in people.
- The MRSA strain that was found in all the horses and most of the people was a very rare type - not the usual sequence type 8 (ST8) we're used to finding in horses in various other parts of the world. This one was an ST5, spa-type t535, SCCmec type V, which is even rare in the human population.
- The primary action taken to get the outbreak under control: increased infection control measures, including isolation of infected and colonized horses which were then handled with contact precautions (e.g. gloves, gowns), discharging horses from hospital as soon as medically possible to decrease transmission pressure, and having a nurse from the NCIC come in to instruct personnel on the measures to be taken, including emphasis on hand hygiene and increased use of alcohol-based hand sanitizer.
- In this outbreak, decolonization therapy was prescribed for all colonized personnel.
The report does not mention whether or not personnel at the hospital were required to submit to being tested and undergoing decolonization therapy. This can be a very tricky issue to handle, and it depends on what the local laws are. In Canada, employees cannot be forced to undergo testing or treatment, but in some other countries MRSA-positive healthcare workers may not be allowed to even work until their carrier status is cleared.
Interestingly enough, just a year or two before this outbreak occurred a study (as yet unpublished) had been carried out in the same region, during which they found MRSA in 7.2% (6/83) of hospitalized horses and none in horses from local farms. There is no mention regarding whether or not the hospital had taken measures to eradicate MRSA from the facility before the clinical infections that triggered the outbreak investigation occurred.
This was a typical MRSA "iceberg" - a couple of clinical cases were triggers for an investigation that found a lot more horses and people were actually carriers. This is exactly why it's important to remain diligent about infection control measures like hand hygiene at all times, so that pathogens like MRSA don't move in "under the radar." The authors of the paper summed it up nicely (although I'd leave out the part about decolonization):
"Strict implementation of hand hygiene, isolation of colonized and infected horses, decolonization
of colonized personnel and above all, constant education of veterinary students and personnel about the importance of infection control measures are required in order to decrease the risk for colonization and infection of both horses and personnel by MRSA and other pathogens."
More information about MRSA in horses is available on the Worms & Germs Resource - Horses page.
ProMed Mail's monthly US rabies update often contains some interesting cases, and the last one is no exception.
A llama in Georgia became aggressive, started biting itself and was spitting at one of its caretakers. A spitting llama certainly doesn't mean rabies (I have dodged enough llama spitballs to know that) but any sudden change in behaviour, especially with aggression, should raise some major red flags. Here, the llama was diagnosed as rabid and the person that was spat on is receiving post-exposure treatment.
A bobcat attacked a man and boy in Massachusetts, and not surprisingly, was diagnosed with rabies. In this case, the bobcat pounced on the man, bit his face, clawed his back and held him in something akin to a bear hug, before moving on to the man's nephew. Wild animals don't typically attack except under extenuating circumstances (e.g. being cornered, protecting offspring), so this type of event should be considered a rabies exposure until proven otherwise. The man shot the bobcat and it was confirmed as rabid.
In an all-too-common scenario, a family that took in a stray kitten ended up needing post-exposure treatment because the kitten was rabid. They found the sick kitten and tried to nurse it back to health, but it died the next day. Fortunately, animal control arranged for rabies testing, something that could have easily been overlooked if no one thought about rabies and just assumed the kitten was sick for some other reason. Two dogs in the household were also considered exposed, but fortunately had been properly vaccinated, so typical recommendations would be for a 45-day observation period versus 6 months strict quarantine or immediate euthanasia had they not been vaccinated.
In a similar scenario, two women are undergoing post-exposure treatment after being bitten by a stray kitten they were trying to catch. After they caught the kitten, they took it to a local Humane Society, where it was euthanized because of the bite. This ended up being an efficient approach, but more often there would be a 10 day observation period of an animal that had bitten someone, to see if it developed signs of rabies. If signs occurred the animal would be euthanized and tested for rabies, but if not then (theoretically) the animal would not have been shedding rabies virus at the time the bite occurred. Immediate euthanasia after a bite is not the typical recommendation, so I wonder whether the kitten was already showing some signs of disease. Otherwise, it wasn't a textbook approach to bite management but it ultimately resulted in the right outcome.
These cases have a few recurring themes:
- Changes in animal behaviour should lead to consideration of rabies.
- Be wary of stray animals. It's best to stay away from them. If you end up taking in a stray, if it gets sick and dies, ensure that it is tested for rabies.
- Vaccinate your pets because you never know when you'll encounter rabies.
When I was in general practice, I remember going into an appointment and being introduced by an owner to his cat named "Big Screen TV." Upon seeing my surprise at the name, the owner explained that the medical emergency the cat had the year before cost as much as the big screen TV he wanted, so he renamed the cat.
If that's the case, then L.A. Times columnist David Lazarus might want to call his cat "SUV." Lararus developed an infection after a cat bite that required surgery and extensive medical care. His hand was saved, at a cost of about $55 000. The article describing the ordeal it is focused on the financial aspect and the bizarre approach to hospital billing in the US, so there's not much information on the bite or the infection itself, but it's yet another example of why preventing bites and good bite care is important, regardless of how serious the bite may appear at first.
One on the things we try to do with the blog approach to getting zoonotic disease and infectious disease information out is to put a personal spin on stories. Whether it's new puppy issues, a rabid bat in my house, zoonotic disease issues at my kid's daycare or something more mundane, that personal touch sometimes helps keep things in perspective.
Knowing more about what we do and why might also help with understanding how our thoughts and opinions come about. An article posted on atGuelph details our own Dr. Maureen Anderson's ascent in the veterinary world from undergrad to infection control researcher, including her groundbreaking infection control surveillance in veterinary clinics. I'll let you read the story yourselves through the link highlighted above...
1) Do you know what a bully stick actually is?
2) Do you know what's in it?
A recent study headed up by Dr. Lisa Freeman, published in this month's Canadian Veterinary Journal (Freeman et al., CVJ 2013;54:50-54), looked into this by asking people what they thought bully sticks were made of, and testing the treats for calorie count and bacterial contamination.
The answer to question 1 is: bully sticks are raw, dried bull penis (which explains the need for a cuter name).
- Only 44% of people surveyed knew that.
Also, bull penis is considered a by-product, yet 71% of people that fed bully sticks to their dogs said they avoid by-products in food.
- This just shows a lack of understanding about what by-products are and their nutritional value. Many people classified things that are prohibited from by-products as being by-products, such as hooves, horns, road kill and euthanized pets. By-products aren't always bad and can, in fact, have good nutritional value. Also, they can be environmentally friendly and ethical since they are often made from nutritionally valuable parts of the animal that might otherwise be thrown out, thereby providing food for pets without taking anything out of the human food supply chain.
"What's in it?" was approached from 2 standpoints:
Firstly, caloric content was assessed.
- Treats often get ignored when thinking about a pet's caloric intake, but calorie-dense treats can certainly contribute to obesity. Fifty percent of people surveyed underestimated the calorie counts of bully sticks. The average caloric density was 3 calories/gram, and given the variation in size of bully sticks, total calorie counts for a single stick ranged from 45-133 calories (9-22 calories/inch). So, yes, size matters.
Secondly (my bit part in this study), we looked at contamination by a select group of bacteria.
- Salmonella wasn't found, which was encouraging since high Salmonella contamination rates have previously been found in some treats (mainly pig ears), and contact with pet treats has been implicated in some outbreaks of salmonellosis in people. We found Clostridium difficile in 1 treat (4% overall). That doesn't worry me too much since it's increasingly clear that we encounter this bacterium regularly. With common sense and handwashing, it's probably of little risk, but in some people (e.g. elderly, people on antibiotics, people with compromised immune systems) it might be more of a concern. We also found methicillin-resistant Staphylococcus aureus (MRSA) in one sample. This was a "livestock-associated" MRSA strain that can cause infections in people, but the risk is unclear. Theoretically, it's a potential source of exposure. If someone got MRSA on their hands from the treat then touched their nose (where MRSA likes to live) or a skin lesion (where it can cause an infection), then it could potentially cause a problem. Overall, the risk is probably quite low, but it's another reason to wash your hands after handling treats.
None of this means dog owners need to avoid bully sticks. It does mean that you should pay attention to what you feed your pet, think about treats when considering your pet's caloric intake (especially if your dog is overweight), keep treats away from high risk people (e.g. don't use a bully stick as a teething toy) and wash your hands after handling dog treats (of any kind).
Photo: A variety of bully sticks (also known as pizzle treats) often fed to dogs as chew treats (photo credit: Gergely Vaas 2006 (click for source))
I seem to write about this bug a lot - disproportionately for a rare cause of infection - but it just keeps getting attention. Reading the title of a recent article "Woman loses legs, fingers to rare infection from dog bite," it was an easy guess that the infection was caused by Capnocytophaga canimorsus. That's the type of dramatic disease this bug can cause, and as hard as it is to say "lucky" about someone that loses digits or limbs, they are lucky since death rates are very high with this infection.
Capnocytophaga canimorsus is a strange little bacterium. It's found in the mouth of pretty much every dog, so people get exposed to it quite commonly, yet it rarely causes disease. However, when it does cause disease (often after an otherwise inconsequential bite), it's bad.
In the most recent report, a 48 year old woman received some minor bites breaking up a fight between two family dogs. The next night, she had a fever and was vomiting, and things went downhill from there (click here to read the full story). An unusual aspect of this case was that the woman didn't have any of the risk factors that are typically present in a person who gets a Capno infection, such as not having a spleen, being an alcoholic or having an immunosuppressive disease. It is unclear why this bug, which is normally quite innocuous to an otherwise healthy person, almost killed her.
An infectious disease physician at the hospital made a few recommendations:
"If a person experiences a dog or cat bite it’s reasonable to have it examined, especially if it’s swollen, painful or red."
- Pretty good advice. It's never a bad idea to get a bite examined, and in some situations, it should be mandatory (e.g. bites over the hands or face, bites to immunocompromised individuals).
"It’s important for the public to not only closely watch animal bites but also to make sure pets are current on their shots and that the owners are up-to-date on tetanus shots."
- Good general advice, but not really related to Capno.
"Dog owners should use caution when trying to break up a fight between animals, she said. Instead of reaching near a dog’s mouth, pull the tail, she advised."
- I'm not so sure about this one. Grabbing a tail of a fighting dog sounds like a good way to get bitten, although reaching near the mouth of a fighting dog would be just as bad or worse.
"Animals that are the source of such infections don’t need to be euthanized, Mondy said, but the dog that bit Sullins was put down for various reasons, including increasing aggressiveness and concerns about exposing babies in the family to the animal."
- Capnocytophaga should never be a reason to euthanize a dog since basically every dog is a carrier. It doesn't matter if there's a baby in the house or not. If the dog's dangerous because of its biting, that's a different story.
This article, along with various other recent reports, makes me ask a couple of questions:
Are Capnocytophaga canimorsus infections getting more common?
- I don't know. It's possible, as disease trends can change. It could also be that reporters are picking up these cases more often since they tend to be dramatic.
Are more low-risk people becoming infected?
- This one concerns me a bit. Traditionally, when I saw a report of Capnocytophaga in the literature or lay press, I could guarantee I'd eventually come across a statement about the person not having a spleen, or less commonly being an alcoholic or having some other immunocompromising problem. Again, it may just be my impression but I'm seeing more reports where a risk factor isn't apparent. It could be that an immunocompromising problem is there but is not known, but this report, along with some other recent news articles and a published case report, raise concern about the potential for this bug to cause disease in the absence of traditional risk factors.
This doesn't mean owners should fear their dogs, since it's still a very rare problem. However, it re-inforces the need to:
- Reduce the risk of bites through proper training (of both the dog and people who interact with it).
- Use prompt and proper first aid measures after any bite.
- Ensure that people who are at high risk for infection, particularly people without a spleen and those with compromised immune systems, always seek medical attention promptly after a bite.
Santa gives the reindeer a few months off every year, so inevitably they're going to cause trouble.
A health board inquiry is under way after a young reindeer was taken into a Glasgow Children's Hospital and allowed to interact with patients. The reindeer fawn, from a local reindeer farm, was paraded around the hospital grounds as part of an organized event. That's great. The kids could see something unique. However, the problem occurred when a staff member decided to take the fawn inside so more young patients could see it. By doing that, the fawn was turned into a "therapy animal," meaning all the various recommended precautions for a therapy pet should apply (including a prohibition on bringing farm animals into a hospital).
It essence, good intentions + lack of critical thought + lack of clear local guidelines lead to this situation, which has caused an outcry amongst some groups (and probably a similar "so what?" amongst others).
Here are some interesting bits from the article:
"It had been checked by a vet..."
- Okay, good start, but for what was is checked? You can't tell what infectious agents an animal carries by looking at it. We know that young animals are more likely to shed various potentially harmful microorganisms, and deer can be sources of very harmful bacteria like E. coli O157.
"It is understood that the patients who did pet the fawn were later given antiseptic wipes with which to clean their hands."
- I wonder what "later" means. I suspect it wasn't right after animal contact.
“I don’t suppose any animal, no matter how well shampooed and clean it was, should be allowed into a hospital without prior knowledge and the correct arrangements made,” [Dr. Jean Turner of the Scotland Patients' Association] said.
- A reasonable statement. She's not saying "no animals," she's saying "no animals without a proper plan."
"I think it was well-intentioned, but I don’t think anyone was thinking about the consequences of taking a live animal like that to a hospital.”
- That sums it up nicely.
Every animal (and person) is carrying multiple microorganisms that could make someone else sick. Usually that doesn't happen, and we need to live life, not stay locked up in our bedrooms. However, some animals are at higher risk of shedding pathogens (e.g. young animals, farm animals), some situations make it more likely that an individual animal will contaminate the environment of patients (e.g. interacting with a farm animal, taking a non-house-trained animal inside) and some people are at much higher risk of serious disease when they encounter various bugs (e.g. hospitalized kids).
I'm sure some kids had a great time, and the overall risk was probably low. However, was there really any benefit here beyond a properly run pet visitation program with appropriate animals, established protocols, good hygiene practices and proper handler training?
Pet therapy programs are too important to be compromised by illogical events like this that sometimes cause a knee-jerk "no animals in the hospital" response. That's why there are good international pet visitation guidelines and why people need to follow them.
The fact that Salmonella and reptiles go together is old news. I often get questions about testing reptiles to see if they are Salmonella carriers and I tell people not to bother since even with a negative result, I'd consider the animal to be positive. A recent study in the Journal of Zoo and Wildlife Medicine (Goupil et al 2012) provides more evidence for this.
This study involved testing 12 snakes used in a public educational program, by sampling them weekly for 10 weeks. Here are the highlights:
- 11/12 snakes were positive at least once.
- 58% of snakes were positive on 5 or more weeks.
- On a weekly basis, between 25-66% of snakes were positive.
- Fifteen (!) different types of Salmonella were identified. Nine snakes shed 2 or more different Salmonella types over the study period.
- Two samples from feeder rodents were also positive.
This shows nicely how a single negative sample doesn't guarantee that a snake is truly negative. It also shows how common Salmonella is in snakes. The positive cultures from the feeder mice aren't surprising either, but shows that even if a snake was truly Salmonella negative, it could be exposed at any time through its food, and that there is potential public health risk from contact with feeder mice (something that large international outbreaks of human infection from infected feeder mice have shown).
This study just reinforces some key concepts:
- Assume all snakes are Salmonella carriers.
- Use good hygiene practices around snakes and feeder rodents.
- Keep snakes away from high risk individuals (e.g. the very young, elderly, pregnant, immunocompromised).
- Don't waste your money testing your snake for Salmonella. Focus your efforts on smart and practical management practices.
More information about reptiles and Salmonella can be found on the Worms & Germs Resources - Pets page.
Yes, the title's a bit misleading. Equine herpesvirus (EHV) is everywhere, since the virus circulates widely in the horse population internationally and lies dormant in the bodies of a large percentage of healthy horses. However, cases of EHV-1 neurological disease get attention because of the severity of disease and the potential for outbreaks (for reasons we really don't fully understand). Seeing a report of a new case isn't surprising, since they are always occurring somewhere, but it's worthy of note for horse owners in the area or those who might have visited the area recently.
The latest incident, reported by TheHorse.com, involves a Standardbred horse that raced at Sports Creek Raceway, a small track in Michigan. The animal raced on December 22nd and started showing signs of neurological disease on December 23rd. It presumably didn't pick up the virus at the track, because 24 hours is on the very low end of the potential incubation period, so the main concern is that the horse might have been shedding the virus while at the track. It's possible that EHV could have been transmitted to other horses via aerosols (virus on small particles released when the horse was breathing, shorting or coughing), contaminated items that were used for multiple horses (e.g. buckets), or on the hands or clothes of people. That's why good general infection control practices are needed at tracks and other horse competitions at all times - to reduce the risk of transmission when an infectious but currently healthy animal is present (and there's room for a lot of improvement).
Typically, the incubation period of EHV-1 in a neurological disease outbreak isn't very long: about 4-6 days or so. If anyone had a horse at the track on the 22nd and it's still healthy today (January 4th), odds are it won't be affected. However, there are some instances when the incubation period can be longer, particularly with abortions in pregnant mares. Also, horses could have been infected and not gotten sick, but still be able to spread the virus to other horses with which they subsequently have contact. For this reason, several racetracks have imposed temporary entry restrictions on horses that were at Sports Creek in December. It's probably a low risk situation, but you can never put an outbreak "back in the bottle," and a little short term inconvenience is much better than the major hassles (and deaths) that can come with an outbreak.
The affected horse was in pretty rough shape neurologically but ultimately recovered, as can occur with EHV-1 neurological disease. If your horse has to have a neurological disease, this is probably one you want since full recovery is possible. EHV-1 will probably live within this horse's body for a while, if not lifelong, but that's true of a large percentage of other horses as well, so after a few weeks (when the likelihood of him shedding the virus decreases), he probably poses no more risk than any other horse.
A recent article in the Toronto Star detailed an "underground railroad" that helped get stray dogs out of Afghanistan and into homes in North America and the UK. While it's a nice heartwarming Christmas story, the Scrooge side of me starts asking questions about whether this is a good thing. To me, there are two different scenarios here:
One is the military person who befriends a stray dog while on deployment and wants to bring it home with him/her. I get that. A bond has developed between the specific person and dog, and I completely understand the rationale.
The other scenario, which is the one that raises my concerns, is when this type of action expands to groups that start "rescuing" random Afghan dogs that are then shipped back to Canada for adoption. This is an ongoing issue which has come up with dogs coming from a variety of countries under various circumstances (e.g. Hurricane Katrina dogs). This is very different than the first scenario above. While it's certainly great for most of the adopted dogs, I have a harder time justifying it. Here's why:
Cost: Thousands of dollars are spent on each dog. Is that a wise investment? Could these funds be used differently to help more animals?
Local shelters: It's not like we need to encourage immigration of stray dogs because our shelters are lacking in dogs. I don't know of any shelters that complain about a shortage of dogs for adoption. How can we justify spending thousands to import dogs when we already have an oversupply here? Does adoption of an imported dog (that cost thousands) result in euthanasia of an additional local dog, since there's a finite owner population?
Disease: Thanks to Canada's basically non-existent control over canine importation, this creates disease risks. If I wanted to do a study of Salmonella shedding by dogs in Afghanistan and have fecal samples from healthy dogs sent to me, I'd have to: A) Get an import permit from the Canadian Food Inspection Agency (CFIA); B) Have a facility inspection performed to confirm that my lab fulfills containment level 2 practices; and C) Get an import permit from the Public Health Agency of Canada. To import the whole dog, poop and all, I just need to produce a rabies vaccination certificate. If the dog is less than 3 months of age, I don't even need that. We've seen leishmaniasis in Ontario recently from dogs imported from Greece. There were major concerns about heartworm from "hurricane Katrina" dogs that were imported from Louisiana. A dog incubating rabies was imported by a US military person a few years ago. This is more than just a theoretical risk.
I'm not saying don't do this, I'm saying let's think about the costs and the benefits, and if it's to continue, let's make sure we have some logical and practical control measures in place.
Are the overall benefits worth the risks? Do people really want those dogs, or do they just want to say they own an Afghan rescue dog? What's the infectious pathogen burden in imported dogs? What diseases occur in imported dogs? Who's tracking these issues? (Answer: no one.) Should any regulations be put in place to reduce the risks?
Heartwarming story, but one that should at least raise some questions.
The 15 cm of snow that fell last night is as good of an indicator as any that agricultural fair season is over in this region. But, planning ahead is important (and often not done well with fair petting zoos), so it's never to early to make a plan for next season. Petting zoos can be fun and educational, but are also associated with infectious disease risk. There's always some inherent risk with any kind of animal contact, since all animals (and people) carry a multitude of infectious agents. However, understanding pathogen shedding patterns is useful to help determine the best control measures.
A recent study in Comparative Immunology, Microbiology and Infectious Diseases (Roug et al 2012) looked at shedding of selected pathogens by cattle, sheep, goats, pigs, poultry, rabbits and horses at a California county fair. Here are some of the highlights:
- E. coli O157 was found in one animal. This is the main outbreak concern when it comes to petting zoos, because very low numbers of bacteria are required to cause disease and human infections can be very severe. Surprisingly, the positive animal was a pig, not a ruminant, as would be typical.
- Salmonella was isolated from feces of 3 animals: 2 pigs and 1 chicken.
- Campylobacter jejuni, another potential cause of diarrhea in people, was found in 3 animals: 2 cattle and 1 sheep. The 2 positive cattle were adult dairy cattle and they represented 17% of all tested cattle. That's a surprisingly high rate for adult dairy cattle, in my experience.
- Other Campylobacter species were found in 2 cattle, 3 goats (30% of all goats tested) and 1 chicken.
- Antibiotic-resistant E. coli were common, particularly in pigs.
- The parasites Cryptosporidium and Giardia, and the bacterium Vibrio, were not found.
The study didn't look at other aspects of the petting zoo, such as the types of contacts that were allowed, but based on the pictures that were included with the paper, they weren't optimal. Given the results, the picture of two children in the pen with the pigs (including one child who was sitting on the ground leaning against a pig) should raise some concern.
Does this study change anything? Not really, but more information can't hurt. We know that petting zoo animals can carry pathogens, and we have to assume that every animal in a petting zoo is carrying something that could cause an infection given the "right" circumstances. That's why there's a focus on good general hygiene and infection control practices (especially hand hygiene), along with excluding animals that are at particularly high risk. As the authors say "The study findings should not be interpreted as a deterrent to visit agricultural fairs, but as a reminder that good hygiene and sanitation are critical in these settings."
Following up on my recent post about MRSP in rats, here’s a story about MRSA in an alpaca (Stull et al, Can Vet J 2012). As far as we know, it’s the first report of MRSA in an alpaca (or any camelid).
The report relates to our large animal hospital, where we perform MRSA screening of all horses at admission, weekly during hospitalization and at the time of discharge. It's all part of our infection control program, and the screening is designed to help reduce the risk to horses and our hospital personnel, since this multidrug-resistant bacterium is endemic in the Ontario (and broader) horse population, and outbreaks can occur in equine hospitals.
While alpaca’s aren’t horses, and we don’t see that many of them here, they sometimes get screened anyway since screening is being done on most of the other patients.
This case involved a neonatal alpaca that was admitted with its mother because of severe respiratory disease. The cria (baby alpaca) was very sick and was ultimately euthanized about 36 hours after admission.
Surprisingly, the admission MRSA sample from the cria was positive. In this case, MRSA wasn’t involved in the animal's illness. The cria didn’t have any evidence of bacterial infection, so this was an incidental (but interesting) finding.
When the bacterium was tested further, it was classified as CMRSA-5 (Canadian epidemic MRSA-5), a human strain that also predominates in horses in North America. The mother alpaca was MRSA negative. Presumably, the cria picked up MRSA from the farm environment or a person shortly after birth. MRSA (especially CMRSA-5) carriage rates are high amongst horse owners and horse vets compared to the general public, and it would have been nice to have determined if there were any horses on the alpaca’s home farm, but we couldn’t get any follow-up information.
This single case is probably of limited concern in the grand scheme of things. It’s likely an "oddball" infection rather than an indication that MRSA is a serious threat to alpacas, or that alpacas are a relevant source of human MRSA infection. However, that’s largely what was said when MRSA was first found in horses in the late 1990's and early 2000's, and it has since become a significant issue in that species, so the potential for MRSA to become a problem in alpacas can’t be completely dismissed.
If nothing else, the occurrence of this case is an indication of the need think broadly when it comes to infectious diseases, since many pathogens don’t have species boundaries. CMRSA-5 is a human-origin MRSA strain, but it’s worked its way outside of its natural host. It’s not the first and certainly won't be the last bug to make its way from people to animals.
This story's a couple of weeks old, but Sonoma County (California) residents have been warned about an outbreak of salmonellosis in songbirds. Outbreaks of salmonellosis occur occasionally in songbirds such as finches, and can result is lots of sick and dead birds. There are also risks to other species, including cats and people.
Why cats? Cats can be exposed to Salmonella from eating infected songbirds, and sick birds are typically a lot easier to catch than healthy ones.
Why people? People can be exposed to Salmonella from areas the birds have contaminated, particularly bird feeders and their vicinity. People have been advised to remove bird feeders or clean them regularly, and to promptly remove dead birds from under feeders.
- Removing bird feeders temporarily might help keep birds (including sick birds) farther away from people. It's not going to hurt the birds since other food supplies are typically abundant.
- Washing feeders can reduce the Salmonella burden but it could also increase the risk to people if they contaminate themselves while washing them. Certainly, people should not wash bird feeders inside the house, especially not in the kitchen sink. They should also take care to avoid contaminating their clothing and make sure they wash their hands thoroughly after finishing with the feeder.
"Songbird fever" is a colloquial name for salmonellosis in cats - a testament to the potential for feline infection. It's uncommon but can be severe, and cats can act as a bridge between sick birds and people by bringing Salmonella into the household. This is just one of many reasons why domestic cats are better off living indoors.
A year or two ago, I received an email from Dr. Chelsea Himsworth, who was doing some interesting work looking at different bacteria found in rats in Vancouver's Downtown Eastside. This is an impoverished urban neighbourhood with lots of homeless people, IV drug users and HIV-infected individuals... and lots of rats. Dr. Himsworth, a veterinary pathologist working on a PhD at the University of British Columbia, is assessing potential health risks posed by rats to this type of population. The reason she got ahold of me was to see if I was interested in looking for some different bacteria, like methicillin-resistant staphylococci, in these rodents.
If you look, you often find, and that was the case here with methicillin-resistant Staphylococcus pseudintermedius (MRSP). This multidrug resistant bacterium was found in nasal or oral swabs from 2.1% of rats (Himsworth et al, Emerging Infectious Diseases 2013). So it was relatively uncommon but certainly present.
One question: from where did it come? Most MRSP isolates found were the same as the most common strain found in dogs, so presumably the rats picked it up directly or indirectly from pets or stray dogs. However, there was also a type we've never run across before. That could mean that there is a separate rat-associated MRSP strain, but more likely it means this strain is present in dogs in Vancouver and we just haven't found in dogs elsewhere yet (there aren't many of us typing MRSP, and we find new strains not uncommonly). While dogs and rats presumably don't spend time lounging around together, there is certainly potential for direct or indirect contact between dogs and rats, and rats have been found to harbour dog-associated oral bacteria in the past.
Another question: what's the risk to people? The risk of infection is probably limited, but not zero. MRSP can cause infections in people but doesn't do so very often. MRSP is unfortunately becoming fairly common in dogs, so people are commonly exposed, yet human infections are still rarely diagnosed. So, the risk to humans from these rats carrying MRSP is pretty low overall, although we'd rather not see new reservoirs for this bug.
What about the rats? Rats may be the innocent bystander here, having been infected by dogs. We don't know whether MRSP causes infections in rats. It probably can in certain circumstances.
Can rats spread this to dogs? I guess it's possible. Rats are probably not contaminating the environment too heavily with this bug from their noses or mouths (compared to dogs), but direct transmission if a dog caught a carrier rat could certainly be possible. The risk to the dog population is pretty low since this pathogen is well established in dogs already and there's a lot more dog-dog than rat-dog contact.
Why does an antibiotic-resistant bacterium live in these rats when they're not receiving antibiotics? Good question. Antibiotics certainly help when it comes to selecting for resistant bacteria, but they're not absolutely required. There are a lot of other factors that can also play a role, so rats don't need direct or indirect exposure to antibiotics to acquire MRSP (or other multidrug-resistant bacteria). It could be that they are just commonly exposed and the bacterium only hangs around for a short period of time, or that there are some other factors in the rats, their food or their environment that select for these resistant bacteria.
If you're in Toronto (or probably anywhere in Canada), you've probably heard a lot about Darwin, also known as the "Ikea Monkey". Darwin is a seven-month-old rhesus macaque (Macaca mulatta) that was found wandering around an Ikea parking lot on December 9 in a designer winter coat. He was seized by Toronto Animal Services since non-human primates aren't legal pets in Toronto, and the owner has been fighting to get him back ever since. She has organized protests. She's filed lawsuits. She's planning on moving to a neighbouring region that currently does not prohibit non-human primates as pets. Of course, not wanting to be known as the home for wayward monkeys and their wayward owners, that very region is in the process of enacting a bylaw banning such pets. Darwin's owner is trying to get him back and move ASAP because the bylaw will not apply to existing pets already living in the region when it comes into effect.
For this post, I'll stay away from some of the stranger aspects of this fight and the exotic pet issue in general, and address one basic question: are rhesus macaques good pets?
That one's easy. No.
Why? There are a variety of reasons.
Number one on the list is Cercopithecine herpesvirus (also known as herpes B, herpesvirus simiae or simply B-virus). This is the macaque version of the herpesvirus that causes cold sores in people. It's very common in macaques, and the vast majority of captive macaques are infected. A problem with herpesviruses is that they hang around for life, being shed intermittently and unpredictably. While this virus doesn't cause a major problem in the monkeys, it can cause fatal encephalitis (brain swelling) in people, most commonly after being transmitted by a monkey bite.
Other infectious diseases are also of concern. Bites are a major issue, both from the trauma associated with them and bite infections from the range of bacteria present in the animal's mouth.
Other injuries can be a problem too. While macaques aren't very big, they're strong and they can be aggressive. Injuries to people can happen from aggressive behaviour or over-exuberant play.
The animal welfare aspect can't be ignored either. These animals have complex care requirements. You can't just lock them in a room, toss in some monkey chow every once in a while, and take off for the weekend leaving the neighbour's kid in charge. These animals need a proper diet and care, and that's not something everyone provide. Stress-associated health and behavioural problems are quite common in pet macaques.
The lifespan of these monkeys also needs to be considered. If properly cared for, they can live up to 25 years. That's a long time to deal with a high maintenance animal. What happens if the owner gets sick or dies, moves somewhere that the animal's not allowed, or for whatever reason can't take care of it anymore? That's true for all pets, but the longer the lifespan, the greater the chance of one of these things happening, and harder it is to get someone to take the animal. It's not too hard for someone to adopt Aunt Edna's 15-year-old cat that rarely leaves the couch and isn't going to be around that long. It's different with a young macaque that's going to live many years and require intensive effort for that entire time.
Similarly, a paper co-authored by people from CDC (Ostrowski et al, Emerging Infectious Diseases 1998) states clearly "The extremely high prevalence of B-virus along with their behavioral characteristics make the macaque species unsuitable as pets."
Darwin needs to go to a good sanctuary or zoo, where he can be a monkey, interact with other monkeys, and have a happy, healthy and species-appropriate lifestyle.
Zoo Atlanta has closed its parakeet exhibit after one of the birds died of Chlamydophila psittaci infection. The concern is that this bacterium can cause infection in people (sometimes called parrot fever). Infection of humans is uncommon and usually just causes flu-like disease, but it can be very serious, especially if not diagnosed properly in a timely manner.
The zoo is going to test the flock and decontaminate the facility. The question is, "what will happen if other birds are positive?" Actually, the question probably should be "what will happen when other birds are identified as being positive?"
Chlamydophila psittaci gets the "psittaci" component of its name because it is commonly found in psittacine birds (e.g. parrots, parakeets and other related birds). The dead bird got the bacterium from somewhere, and living communally with other psittacines means that the odds are very good that multiple birds are now carrying it, since birds can carry this bacterium without any signs of disease. Varying carriage rates in psittacines have been reported in different studies, but in some groups (e.g. breeding colonies) rates can be very high.
Concern about the aviary is reasonable, since this bacterium can be spread through the air, mainly through inhalation of contaminated material that's been aerosolized (e.g. dried feces that end up in dust in the air). If there's no direct contact with birds, through, the risk to the public is probably very low. Some management practices can be used to reduce the risk of aerosolization of the bacterium and reduce the risk of exposure of the public. These could include using cage litter that isn't dusty, regular and thorough cleaning of the area and cleaning in a manner that reduces the risk of aerosolizing the bacterium (e.g. wetting things down before cleaning, not using a vacuum unless it has a HEPA filter).
So, what about testing? One of my standard lines is "never do a diagnostic test without a plan to use the results." Hopefully, the zoo has thought about what they'll do with positive results, since it's likely they'll have many.
Testing is a somewhat controversial area. It's been recommended that birds in areas where they will be exposed to a lot of people be tested. That could apply here, depending on how the birds are managed. One issue with testing is it's far from 100% accurate, so it's only one part of the control program and testing limitations need to be understood. Testing makes the most sense in a population of birds that is closed, meaning there are no new birds coming in. That way, a couple of rounds of negative tests can give you pretty good assurance that the group is negative. Positive birds can be quarantined and treated to try to eliminate the bacterium. If most of the group is positive, it makes it pretty difficult to eliminate. A single round of testing or testing and then bringing in new birds doesn't help too much.
Overall, the risk is greatest for zoo personnel who work with the birds and their environment. Good infection control protocols should already have been in place to reduce the risk of disease transmission, but presumably those are being revisited. It's often a controversial subject since use of barriers such as eye protection and an N95 mask are often recommended when cleaning cages, but this is rarely done and there's (reasonable) reluctance to do so because of the rarity of disease, the commonness of the procedures and the fact that people have been doing this for years without these extra precautions. It's a tough area to address and it requires careful consideration of the costs and benefits. Other important points for psittacosis control include avoiding bringing in new birds, avoiding mixing of different groups of birds, checking new birds for signs consistent with C. psittaci infection before bringing them to the facility, quarantining new arrivals and educating people who work with the birds.
One key factor, regardless of what's done, is that people who work with psittacines need to know that they are at increased risk of psittacosis. Their physicians also need to know that they work with psittacines (and that psittacosis is a potential concern). In this situation, people who have worked with the affected bird (and any other bird that might be a carrier) should know to see a doctor if they develop respiratory or flu-like illness.
About 500 people have sent me this article over the past week, so I guess I should get around to making some comments. The article entitled "Using a dog’s superior olfactory sensitivity to identify Clostridium difficile in stools and patients: proof of principle study" (Bomers et al 2012) is in the Christmas edition of BMJ, an edition in which they typically publish something fun or light. The study describes the use of a dog trained to sniff out C. difficile, an important cause of diarrhea people, especially hospital patients. The premise is that dogs could be used as a rapid and cheap way to diagnose C. difficile infection, and therefore allow for earlier treatment and implementation of enhanced infection control measures.
There were 3 components of the study:
1) Detection of C. difficile on a culture plate
The dog was trained using culture plates containing C. difficile. That's how they have to start, but detecting C. diff on a culture plates is pretty easy. I can do that, and my nose is nowhere near as good as a dog's. Clostridium difficile has a very characteristic odour on a culture plate and odour is one of the methods that's commonly used to determine whether C. difficile might be present on the plate.
2) Detection of C. difficile in stool
For this, the researchers set the bar pretty low. A positive fecal sample was considered one that was culture-positive positive on a test to detect the C. diff toxins. We know toxin tests are pretty insensitive (they give a lot of false-negatives), which is why there's a major movement to replace them with molecular tests. By requiring the sample be positive on both culture and toxin test, it means that the samples had to have been quite positive to be considered (i.e. they didn't test the dog with "weaker" positive samples that may have had less C. diff and C. diff toxin in them). That weakens the results a bit, but they're still interesting.
They presented the dog with 50 positive and 50 negative samples. The dog gave a positive response to all 50 positive and a negative response to 47/50 negative samples.
3) Detection of C. difficile in patients
Here's where it gets more interesting and potentially more relevant, since the real value in a sniffer dog would be to detect C. diff directly from patients, as a rapid and cheap screening tool.
For this part, they enrolled 30 patients with C. difficile infection and 270 controls. One problem I have is that 94% of their controls were non-diarrheic. It raises questions about whether the dog is detecting C. difficile or just diarrhea, since the groups don't just differ by their C. diff status, as would be most appropriate for a control group. The more differences there are between the groups, the greater the potential that a difference other than the one of interest (i.e. C. diff status) is actually the thing that's being detected. There' a big difference between a dog that can detect C. difficile and a dog that just detects diarrhea.
Another issue is that some C. difficile strains don't produce toxins and are not able to cause disease, but they'd presumably be detected the in the same way based on odour, in contrast to tests that are based on detection of the bacterial toxin or genes that encode toxin production.
Anyway, the dog correctly identified 25/30 (83%) cases and 265 (98%) controls. Not as good as current molecular tests but pretty remarkable, nonetheless.
Overall, it's an interesting story and shows how good a dog's nose can be, how smart (some) dogs are, and how thinking outside the box can result in some interesting ideas. Though I don't think diagnostic testing companies have much to worry about at this time in terms of competition from sniffer dogs.
Cool concept. Fun paper. Not coming to a hospital near you in the near future, but not something to completely dismiss.
My youngest daughter Erin is in every-other-day kindergarten and goes to a child care centre on her non-school days. Overall, it's a great place - excellent people, great learning environment and she enjoys herself.
During the initial interview at the centre, what I do for a living came up and we got into a discussion about pets. The person doing the interview talked about how they had policies against bringing in animals because of potential risks and the difficulty in doing it right (e.g. right animals, right supervision, adequate hygiene, informed consent, knowing fears and allergies). In reality, their policies are not quite as strict as they say. I didn't get too worked up about the parent who was apparently bringing a young puppy in for visits. Erin's getting outside the high-risk window now (she turned five this year), she's not afraid or allergic, and she knows how to interact with dogs. Odds were pretty low that anything bad would happen, but it still wasn't right because I doubt there was much supervision or understanding of the dog's health status. As a puppy, he/she was at higher risk for shedding various infectious agents, as well as more likely to bite, scratch and poop on the floor. It's also a risk for high risk dogs owned by people who visit the daycare (e.g. if the puppy happened to be shedding parvovirus and the kids transferred it on their hands or clothes to puppies in their households, like our puppy Merlin). Anyway, like I said, not a great idea but nothing to get too worked up about.
The next issue was a bigger deal. As I was picking Erin up yesterday I saw a bulletin board display that highlighted a recent trip to a pet store by the younger kids. On it was (predictably) pictures of these young kids handling reptiles, including turtles. As I've said before, reptiles can be good pets. But, they are clearly high risk pets and high risk people, including kids less than five years of age, shouldn't have contact with them.
I assume the parents of these kids had to sign a consent form. It probably said something like:
"We will be visiting ___ Pet Store to see and learn about animals."
It probably didn't say....
"We will be visiting ___ Pet Store, where your child may be handling high risk animals."
It definitely didn't say...
"We will be visiting ___ Pet Store, where, contrary to recommendations from the CDC as well as virtually every other public health organization that has put pen to paper, your child will be handling animals that have a high likelihood of being covered in Salmonella. Someone might try to ensure that she washes his/her hands after... maybe... We are optimistic that your child will not join the tens of thousands of people that develop reptile-associated salmonellosis every year and we really hope he/she isn't one of the handful of small children who die from it. Good luck! Please sign here."
There's a difference between a consent form and informed consent.
There's an educational value of interacting with animals and there are animal encounters where the risk exceeds the benefits.
I have no doubt that the field trip was arranged with the best of intentions; however, this shows that there is still a need for education of child care providers about pets and zoonoses. The pet store needs to be considered too, since they probably do this regularly. They should know better, and every pet store employee should know basic information about zoonotic disease risks and preventive measures associated with the pets they sell. Pet store visits aren't inherently bad, but they're "pet stores," not "petting stores," and it should be a look-but-don't-touch interaction.
People sometimes accuse me of being a kill-joy, but they miss the point. My girls would have more fun if we let them roll around in the van while driving rather than restraining them in car seats and booster seats (as often happened when I was growing up). I want my kids to have fun, but I'm not going to let them do things that are that dangerous. I want my kids to have pets and interact with animals, but I want it to be as safe as possible. There will always be a risk of infection or injury, and as someone who's informed and as their parent, I can define the degree of risk that I am willing to accept for them. Child care agencies have to look out for the welfare of the children they supervise. Zoonotic disease exposure prevention is part of that. It's not a matter of taking the fun out of life, it's making sure that we provide safe fun.
BMJ Case Reports has a recent paper entitled “Cirrhosis, cellulitis and cats: a ‘purrfect’ combination for life-threatening spontaneous bacterial peritonitis from Pasteurella multocida” (Hey et al 2012). (I don’t think we'd be able to use a title like that in a veterinary journal, but they often get away with titles playing on the animal side in medical journals.)
The case report describes a man who had liver cirrhosis from hepatitis C infection and alcoholism. He went into hospital with a chronic infection of his leg. He’d been seen various times for this problem and various bacteria had been isolated (leading to treatment with various antibiotics). This time, he had severe swelling of his leg that went from his calf to his groin, along with significant accumulation of fluid in his abdomen. Shortly after admission, he deteriorated and became septic (he developed an overwhelming bloodstream infection) and went into liver failure. Blood samples and samples of fluid from his abdomen were tested and the bacterium Pasteurella multocida was isolated. Fortunately, he responded to aggressive treatment.
Upon subsequent investigation, they found out that the patient had a cat, and that cat "had a disturbing habit of regularly licking the serous exudate [leaking fluid] from the patient’s chronic left leg leg cellulitis." (This probably occurs much more commonly than most people think.)
Pasteurella multocida is a bacterium that’s commonly linked to cats, and it’s a frequent inhabitant of the mouth of healthy cats. The cat wasn’t tested but it’s a reasonable assumption that this infection came from the pet. The patient was given “the appropriate advice with regard to the safe cohabitation with domestic animals” but unfortunately they don’t say what that advice was.
This is just one more in a series of reports that show the importance of asking people about pet ownership and pet contact. Asking that question initially can potentially help identify zoonotic disease risks, as opposed to asking the question after the zoonotic pathogen is eventually found when they’re trying to round out the story.
The authors list some ‘learning points’. I’ve copied two important ones below.
- Domestic animals can, under the appropriate clinical circumstances, pose a risk to an immunocompromised host, particularly if adequate hygienic practices are not adhered to.
- Questioning regarding exposure to domestic animals should form part of the clinical history when assessing immunocompromised hosts, allowing early institution of empiric antimicrobial therapy in the appropriate clinical scenario.
They’re both good points, although I’d remove "immunocompromised." While the risk is lower in people with normal immune systems, some risk still remains and pet contact should be queried all the time.
A recent report in the journal Infection (Chean et al. 2012) describes rat bite fever in a patient with AIDS. I’ve written about rat bite fever before, and it’s not really a surprising case report. Streptobacillus moniliformis, the bug that causes the disease, is found in the mouths of most rats (and in the mouths of dogs more often than we’ve previously assumed). Rat bite fever is uncommon but far from rare, and this report focuses on the fact that it was in an AIDS patient. The case report itself isn’t too noteworthy since we know infection with S. moniliformis can happen even in healthy people, and someone with AIDS is going to be at increased risk of any type of infection.
However, there are a few interesting aspects to this particular case. The report described a 30-year-old AIDS patient who had a rather prolonged course of disease with fever, aches, diarrhea and weight loss, with subsequent development of joint pain and swelling. A large battery of tests didn’t identify the underlying cause. Eventually, "it was noted that he had two pet rats, one of which bit the man on his right index finger 1 month prior to presentation." That should have been a "eureka!' moment for the physician. It doesn’t mean the disease was caused by the bite, but it made it clear that rat bite fever should be considered. The diagnosis was then made and the man received appropriate treatment.
While the clinical aspects of the case aren’t remarkable, there are some noteworthy points to consider:
- It wasn’t until re-evaluation that it was discovered that the patient had rats and had been bitten. It’s quick and easy for a doctor to ask “Do you have pets or have you had contact with animals?” and in a case like this, it could have sped up the diagnosis and appropriate treatment.
- The paper repeats the important statement that pet ownership rates among HIV/AIDS patients are similar to that of the general population. That’s also true for other groups at increased risk of infection.
- They say “Physicians need to be cognisant of this [pet/human] relationship in order to prevent missing the diagnoses of zoonotic infections in their patients.” That’s a critical step. It’s easy to do. It’s not often done right.
I haven’t written much about equine herpesvirus type 1 (EHV-1) outbreaks lately because I have a hard time getting excited about them (from a blog writing standpoint… if one occurs here, that will be a different story). Outbreaks of neurological disease caused by this very common equine virus (one that doesn’t spread to people or non-equids) continue to occur, and it’s hard to say whether we've been seeing more of them over the past couple of years or whether we’re just hearing about them more often. It does seem like outbreaks have truly become more common and more virulent in the past 10 years or so, but I’m not sure it’s continuing to get worse.
The latest EHV-1 outbreak has affected 5 of 7 horses on a central Minnesota farm. At last report, one horse had been euthanized and one was hospitalized at the University of Minnesota. The hospitalized horse is presumably receiving supportive care, such as intravenous fluids and general nursing support. Affected horses may become very weak and sometimes they need to be managed in a sling (see photo), since horses don’t tolerate being unable to stand for long (laying down for prolonged periods of time can damage muscles and nerves, simply because they are crushed by the horse's own weight). Sometimes the bladder becomes paralysed and needs to be drained using a catheter. Numerous other problems can occur since the way this disease affects each horse can be quite variable. Fortunately, the prognosis tends to be reasonable (at least compared to other neurological disorders) if the horse is not severely infected and stays standing or is able to remain upright with the support of a sling. The clinical signs are the result of inflammation of the blood vessels in the brain and spinal cord, and the key is to get that inflammation down and keep the horse alive in the meantime.
In the past, we didn’t worry too much about these horses in equine hospitals. EHV-1 neurological disease tended to occur sporadically, not in the form of outbreaks, and dogma was that once the horse was sick, it wasn’t at much risk of shedding the virus. In fact, for a long time our best stall in the main hospital for neurological cases (which had padded walls, and a ceiling anchor for a sling) was right at the front of our main equine ward. A large outbreak in the US in the early 2000s changed that, and now we take much more aggressive measures to contain this virus, including housing affected horses in isolation and using strict infection control measures. With these precautions, the risk of spreading the virus in an equine hospital is low.
Image: A horse with neurological disease being managed in a sling (source: http://coloradodisasterhelp.colostate.edu)
I write a lot about animal bites, and for good reason since they are common and can be very severe. Usually, it’s dog bites. Sometimes it’s cat bites, or more rarely injuries from birds or other critters. Monkey bites not so much, but they happen. I had an email question about rabies exposure from a monkey bite the other day, and there was a paper in the October edition of Emerging Infectious Diseases about monkey bites amongst US military personnel in Afghanistan.
Some highlights of that paper:
From 2001-2010, 643 animal bites were reported by US military personnel.
- More probably occurred since bites are often underreported.
Dogs accounted for 50% of bites, but many other animals were also involved, including rhesus macaques, a type of primate that is present in the wild and also kept as pets in Afghanistan.
- Macaque bites are even more of a concern than dog bites. In addition to the ever-present risk of rabies exposure, these animals can also transmit Macacine herpesvirus B, which is a very serious pathogen that can kill people. Like any animal, macaques also have a wide array of bacteria in their mouths that can cause infections after a bite.
10 monkey bites were reported in this series.
- Most people who were bitten were young (less than 30 years of age) and male. All were junior enlisted personnel or non-commissioned officers.
- Eight of the monkeys that bit were pets, including one that somehow belonged to US military members (despite orders that US military personnel not adopt or interact with local animals or pets).
- Appropriate wound care was provided following only six of the bites. So, there are deficiencies in understanding basic first aid following bites.
- Only five people received appropriate treatment for herpes B exposure. That’s a concern because of how serious this infection can be.
- Eight received antibiotics. Antibiotics are only indicated in a subset of bites, mainly based on what part of the body is bitten, so it's not clear whether this was really needed (while more concerning issues went unchecked).
- Eight received treatment for rabies exposure.
- No one got sick, fortunately.
Monkey bites aren’t something that most people need to be concerned about in their daily lives, but they are a concern for people living in areas where there are monkeys, as well as those who visit such areas. (I have a vivid memory of swinging a camera case at a monkey in Barbados that for some reason seemed to be less than impressed with my existence).
Bites happen, but some are avoidable. Common sense can reduce the risk. If common sense isn’t enough and you’re bitten, don't panic, but you also can't ignore it. After thoroughly cleaning the wound, it's important to get medical advice about what diseases are of concern and whether anything else can or needs to be done. Physicians working in foreign countries also need to be trained on geographically-relevant risks. Monkey-associated infections are not high on the curriculum of US medical schools, so geographically-relevant training is required for people heading elsewhere to work.
Public health personnel in Chapin, Connecticut (USA) are trying to find a woman bitten by a rabid cat. The woman was driving down South Brear Hill Road when she came across a cat. She picked the cat up from the road and told someone else who was there that the cat bit her. She then drove away, and the cat was subsequently identified as being rabid. Now a search is underway to find the woman so she can be given post-exposure treatment.
This is clearly a high risk situation. As opposed to other public health alerts that try to find people who were in contact with a rabid animal on the off chance that they were bitten or otherwise exposed to the virus, this person was bitten and that creates a very high risk of rabies transmission.
The outcome is simple.
- If she gets rabies, she will almost certainly die.
- If she was exposed but gets post-exposure treatment soon (and completes the recommended course), she will almost certainly live.
It's easy to see how this could happen. The woman probably found the cat looking injured or lost on the road, and wanted to help. However, that action, and failure to recognize the risk associated with the bite, have put her life at risk.
A few general rabies reminders:
- Avoid contact with wildlife or any animals you don't know, especially if they seem sick or otherwise abnormal.
- If you are bitten, make sure the potential for rabies exposure is considered. The animal needs to be observed to see if it is rabid, or it needs to be tested. If the animal can't be monitored or tested, you can't rule out rabies and getting post-exposure treatment is the safest course of action.
More information about rabies can be found on the Worms & Germs Resources - Pets page.
I received an email from a relative the other day with a pet question. I get lots of these, but the surprising part is this relative doesn't have any pets (and I think is generally of the opinion that pets are okay, as long as they're not hers). She was asking about turtles. As a responsible prospective pet owner should, she was looking into the issues pertaining to the pet before getting the pet. I think she was more focused on general aspects of care and management, but zoonotic disease risks play into the equation too. This one was a no-brainer, since they have a young child in the house and reptiles shouldn't be present in households with children less than five years of age. So, problem averted, and the need to make a decision later about removing an inappropriate pet from a household was also avoided (along with the awkward "oh, you got a turtle?" Christmas dinner conversation).
But, what happens when people aren't so proactive? Turtles are often passed from house to house as people get bored with them, as they outgrow small aquariums or as parents of young or otherwise high-risk children tune into the Salmonella risks or owning such a pet. If you don't have a friend willing to take your turtle, what do you do?
Petco, a pet products company in the US, has launched a "turtle relinquishment program," whereby they take in "wayward" or unwanted turtles. As of a few weeks ago, 111 people from 10 US states had surrendered their turtles to Petco. The turtles are sent to a turtle farm in Louisiana.
So, this is an option for individuals (at least in the US) with no local way to rehome their turtle. The fact that the turtles are going somewhere to make more turtles (and more Salmonella) is a bit of a concern, but I can see the greater good. Staff at the farm say that turtles are treated for any signs of Salmonella when they arrive. This is a bit strange, since turtles don't typically develop disease from this bacterium - they simply shed it with no signs. Hopefully that doesn't mean the farm is just treating all the animals. It's basically impossible to eradicate Salmonella from turtles, so if they are routinely treating, they're probably breeding drug-resistant Salmonella along with baby turtles.
I know the typical round of emails is going to follow, from reptile advocates who have pretty much done everything except burn me in effigy (or in real life, fortunately). As I've said before, reptiles can make great pets, just not in all households. I've owned various reptiles myself, but reptiles and small kids don't go together. Too many kids get sick every year from pets like turtles. A small number die. That's just unacceptable.
More information about turtles and Salmonella can be found on the Worms & Germs Resources - Pets page.
Life with Merlin has been busy but going pretty well. There's been no pee on the floor in the past 48 hours so we're making progress. Speaking of pee (which, sadly, I seem to do a lot), we need to decide about leptospirosis vaccination for Merlin.
A good preventive medicine program is important for every pet. There's no "one size fits all" version - the program needs to be tailored for every region and pet/owner combination. We have Merlin's deworming covered. I gave him a booster vaccine the other day, which covers distemper, parvo and a couple of respiratory viruses (adenovirus type 2 and parainfluenza). Rabies vaccination will be coming soon, when he's a bit older (at least 3 months). Now that we have the "core" components covered, we need to think about the elective aspects. One of those is vaccination against leptospirosis.
When thinking about vaccination, it's a cost-benefit decision. The costs and benefits can be hard to accurately assess, but a few basic questions are key: Is there a risk of exposure? Is the disease of concern? Is there a safe and effective vaccine?
Is there a risk of exposure?
Leptospirosis, a potentially life-threatening infection caused by different types of Leptospira bacteria, has been called a "re-emerging" disease in many parts of North America since rates of infection have increased over the last 20 or so years.
Leptospirosis certainly occurs in dogs around here. We don't see a lot of cases but it's far from rare and it can be nasty.
Wildlife are the main reservoir. Infected wildlife shed the bacterium in their urine, and urine-contaminated water and wet areas are the main sources of infection. Raccoons are the biggest concern around here, and there is certainly no shortage of raccoons around my house (including in the garage sometimes). Since Merlin is a Labrador, he's bound to spend a lot of time swimming in ponds and wallowing around in wet areas on our property... prime sites to be contaminated by pee from infected wildlife. So, there's a reasonable chance that he'll be exposed.
Is the disease of concern?
There's no doubt here. While it's uncommon, it can be nasty. Life-threatening infections can occur and kidney failure is a major problem. Treatment of lepto can be difficult and expensive.
Is there a safe and effective vaccine?
Lepto vaccines have had a bad rap. Older vaccines weren't very effective (often not protecting against the strains that are of concern) and were associated with a high rate of adverse reactions. Those former concerns have persisted in some people despite the fact that there's a new generation of vaccines that are much more effective and safer. The new vaccines are better designed, better tested and cover a broader range of strains. There's quality research indicating that they work. Like any vaccine, they're not 100% effective but they are quite good overall.
Information about adverse reactions is harder to get. Adverse event reporting is sporadic at best, but the available information doesn't indicate that these vaccines cause a greater incidence of adverse reactions than any other vaccine. Any given vaccine can cause a problem in any given dog, but the overall risk is low.
So, don't tell Merlin but another set of vaccines is in his future.
With the lingering NHL strike, TV networks are looking for replacement sports. One of my PhD students (who claims he doesn't spend too much time playing around on the internet but keeps coming up with these gems) sent me information about one sport that's not coming to a network near you.
Yes, it's ferret legging. That doesn't really seem like a sport to me...more like a fetish or something someone might do when they're really (really!) drunk. Yet, it apparently exists, evolving from its origins amongst Yorkshire coal miners to a not-much-broader audience.
The rules are pretty simple:
- Tie your pant legs securely around your ankles
- Let someone toss two ferrets down your pants.
- Secure your belt.
- Stand there until you can't take it any more.
"Clean the abrasions thoroughly and hope they don't get infected" is the step no one describes. Wounds are, not surprisingly, common, and some people, like world record holder Reg Mellor, wear white pants to show off the blood strains. Mr. Mellor's world record? 5 hours and 26 minutes.
Interest in ferret legging is dwindling, which is probably a good thing for both ferrets and competitors. There's no mention about whether there are any ferret legging family dynasties, but I suspect that regularly shoving sharp-toothed ferrets down your pants severely limits one's chances of reproducing. That's also good for ferrets and humans alike.
An attempt to be inclusive and create a women's competition involving sticking ferrets up a blouse apparently failed - likely due to relative differences in common sense amongst the genders.
As I mentioned the other day, I took a fecal samples from Merlin, our new puppy, to see what I'd find and show how you have to be careful with interpreting diagnostic test results. In addition to an unconcerning (for me) amount of clostridial bacteria in a fecal smear, Campylobacter was also isolated on bacterial culture. It's important to note that Merlin has not developed any diarrhea this whole time.
Interpreting Campylobacter results can be tough. This bacterium is an important cause of diarrhea in dogs and people, and contact with puppies is a known risk factor for human infection. So, should I be concerned for Merlin or the rest of the family?
The answer in this situation is no.
Why? All Campylobacter are not created alike. There are two main groups of Campylobacter: catalase-positive and catalase-negative. Catalase-positive species, most notably C. jejuni and C. coli, are the main concern in both animals and people. Catalase-negative species tend to be of little to no concern and are very common. We isolated a catalase-negative species from Merlin, one that's not been associated with disease in dogs or people.
Understanding test results and ensuring that testing makes sense is critical. If a lab just reports "Campylobacter positive" as is the case with some (especially labs that just offer PCR (molecular) testing), I wouldn't know what to think of the result. I need to know the species, or at least catalase-positive vs catalase-negative, to put the results into context and come up with a plan. In this case, the plan is to do nothing (or at least nothing we weren't doing already).
More information about Campylobacter in pets is available on the Worms & Germs Resources page.
In a rather impressive effort - considering the issues inherent with working with a virus like Hendra virus, the nature of the disease and the low economic value of a vaccine that would only be used in a very restricted geographic area - a Hendra virus vaccine has been released for horses. Equivac HeV should provide a degree of relief to people in Queensland and neighbouring areas who have been battling this uncommon but devastating bat-borne viral infection.
As a virus that comes from wildlife, Hendra virus is tough to contain. Eradicating the virus in the bat population isn't really feasible, and while measures can be taken to reduce exposure, the risk cannot be eliminated in areas where the virus is present. So, finding a way to reduce the risk of a horse developing the disease after exposure is critical, and the logical approach is vaccination.
Vaccination of horses can also play a huge role in protecting people. All human Hendra virus infections (approximately 50% of which are fatal) have come from direct contact with infected horses, so reducing disease in horses should reduce the risk in humans.
As with most vaccines, it's safe to assume this one isn't 100% effective. It therefore may be a great tool, but people can't then ignore all other Hendra avoidance practices. Individuals still need to take precautions when working around horses that might be infected, regardless of their vaccination status. So, while it's important to avoid complacency, this vaccine should provide a degree of comfort to people who have been living with this virus hanging over their heads (both figuratively and literally, as bats fly around) in recent years.
Life with Merlin is going fairly well and the house training has been surprisingly good (so far). He was straining a bit to poop yesterday so I was wondering if diarrhea was on the way. Diarrhea wouldn't be too surprising since he's had a pretty good shock to his system with a big lifestyle change and a new diet (gradually transitioned, but a change nonetheless). But, so far, so good.
This morning, I collected a fecal sample from him. I'm getting it checked for parasites, as I mentioned the other day. I also did fecal cytology, out of curiosity and because I can do it easily and quickly in my lab. Fecal cytology is a controversial area for diagnosis of bacterial intestinal disease in dogs. Some people use it to diagnose "clostridial" disease and certain other problems. A common statement is that seeing more than 5 clostridial organisms per high power field under the microscope is indicative of a problem. However, a recent American College of Veterinary Internal Medicine consensus statement on the diagnosis of bacterial enteropathogens basically said that this "rule" is pretty useless (disclaimer: I was one of the authors). Yet, some people continue to use it.
Why do I think it's useless?
- There's no evidence indicating that it's accurate. All of the (very few) studies that have looked at this test in dogs have found it to have no usefulness for diagnosis.
- On a fecal smear, you look at a couple of hundred bacteria. That's a miniscule percentage of the trillions of bacterial present in the animal, and there's no assurance that bacteria are equally distributed, so there's no way to tell if what you see is truly representative of the entire bacterial population (it probably isn't).
- There are a few hundred species of Clostridium. Only a few species are known to cause disease. Many of the others are probably important components of the intestinal bacterial population that are important for gut health, so they should be there.
- You can't identify a Clostridium species by looking at it under a microscope. It looks like a purple rod when using a typical Gram stain. The "bad" clostridia look no different than the "good" clostridia. Also, there are many other bacteria that have the same appearance. So, finding lots of "clostridia-like" organisms is incredibly non-specific - it really doesn't tell you much of anything.
Back to Merlin's poop sample: When I looked under the microscope, I could see lots of clostridia-like organisms. Certainly, there were more than 5 per high power field. Yet, he's bright, alert, eating well, and has formed stool. Yes, something could be brewing but I don't see any real sign of that. Some people would treat him with an antibiotic such as metronidazole based on this cytology finding alone. I think that's a bad idea because he's not sick, I doubt he's getting sick, I have no evidence that he has an intestinal bacterial disruption that needs to be treated and the last thing i want to do is mess up his developing intestinal bacterial population with an antibiotic. That's just asking for trouble.
So, no antibiotics for Merlin. Dewormer... that's another story.
The new puppy, now named Merlin, is keeping things busy around here. (Note to self: avoid getting a new puppy during miserable weather. Standing in pouring, driving rain at 4 AM is not fun. Okay, enough whining.)
Yesterday, I wrote about the new puppy's deworming plan. One thing I forgot to mention was the rest of the "herd." By that, I mean Meg, our 11-year-old Lab. Herd health gets a lot of attention in food animals and to a lesser degree in horses, but many concepts remain important for pets. Specifically, when you introduce a new member into the herd, you might change disease risks or required preventive measures for other members of the herd.
Meg lives a pretty cat-like existence. She sleeps, eats, walks far enough to go outside to pee and, well, that's about it. As an older dog who has very rare contact with other dogs, her risk of exposure to many microorganisms, such as parasites, is limited. However, since we brought a new little furry vector into the house, Meg might be exposed to some things that haven't been much of a concern in the past. Her habit of eating whatever she can find (including poop), increases that risk further. So, what's the herd health plan?
It's not too detailed, actually.
- One thing is making sure that we deworm Meg and we don't just focus on the puppy. She might be exposed to anything the puppy is/was shedding. We're usually pretty lax on deworming her in the winter months, but she'll get a couple of doses of dewormer alongside the puppy.
- Poop removal. Since Meg's a notorious poop-eater, we'll want to remove Merlin's waste promptly. That's pretty straightforward. If she can't find it, she can't eat it. It's also important to make sure that old feces aren't left around, because some parasites require time in the environment to become infectious, so regular feces removal prevents accumulation of infective forms of some. The current temperature is at the lower limit of where Toxocara eggs are able to develop into infectious larvae, and the risk will probably be pretty minimal as the temperature drops over the next few days, but it's not hard to make sure the yard gets cleaned up.
- If we find something in the puppy, then we'll have to consider whether Meg might be exposed or at risk too, and decide whether she needs to be tested or treated.
The other aspect of the herd is the non-canine component of the household (i.e. the kids). The key points for that, in terms of zoonotic parasites, are cleaning up feces from the yard, avoiding fecal contact, hand washing, treating the dogs appropriately to reduce parasite shedding and other basic feces-avoidance measures.
Here is another equine update from guest blogger, Dr. John Prescott of the University of Guelph.
Research presented at the Ninth International Equine Infectious Disease conference last week in Lexington, Kentucky, highlighted the dramatic impact that the latest inexpensive genome sequencing techniques are having on understanding microbial disease.
This is well illustrated by an epidemic of S. zooepidemicus upper respiratory tract infection in horses that occurred in Iceland in 2010, described by lead author Sigrídur Björnsdóttir of the Icelandic Food and Veterinary Authority. The infection itself was relatively mild but lasted about 4 weeks, and over the course of the summer affected a large proportion of Iceland’s horses. It caused a headline-stopping movement and export of horses. The disease presented as a laryngitis and persistent dry cough, with a serous [watery] nasal discharge. The infection started at a facility with a water treadmill, and was rapidly disseminated by horses moving from there to 18 other centres across the country, with a high transmission rate to horses within these stables. Since S. zooepidemicus was isolated from the nasal exudate only as the disease progressed, veterinarians investigating the outbreak thought at first that these isolates were opportunistic or secondary invaders, layered on top of an unknown virus infection.
This is where bacteriologists Andrew Waller and Carl Robinson from the United Kingdom’s Animal Health Trust in Newmarket and Matthew Holden from the Sanger Centre in Cambridge became involved. Incredibly, these researchers sequenced the genomes of 290 isolates from the outbreak as well as from an earlier national collection. They used this information to find, to their astonishment, that S. zooepidemicus Sequence Type 209 was responsible for the outbreak. This strain was isolated from the affected farms all over the country, as well as from a case of miscarriage in a person. It could clearly be linked epidemiologically to the outbreak; the date that the infection started was pinpointed to within 5 days. The epidemic occurred so quickly that the genomes of this strain showed almost trivial variation compared to S. zooepidemicus strains that were more established in Icelandic horses.
This is the best description ever of the impact of introduction of a more virulent S. zooepidemicus into a naïve horse population, and will change forever the way that equine veterinarians will think about this underrated pathogen. It illustrates the enormous power of genome sequencing in bar-coding the bad guy.
Andrew Waller also gave a really interesting talk about the diversity of S. zooepidemicus. Sequencing and “sequence typing”, based on multilocus sequence typing (MLST), has identified over 300 sequence types of this species. What is emerging from this is the recognition that difference types cluster with different diseases. For example, strains (sequence types) of S. zooepidemicus that cause abscessation of pharyngeal lymph nodes (“mild strangles”) belong to sequence types that have acquired a bacterial virus carrying a superantigen gene. These are, of course, outclassed by the true strangles organism, S. zooepidemicus subspecies equi, which possesses four bacteriophages with these virulence genes, as well as other nasty characteristics.
Andrew Waller told me that it cost him about $35 to sequence an entire streptococcal genome, which for Canadian veterinarians is now about the cost [Weese comment: or much less than the cost] of sending a swab to a diagnostic lab for culture and sensitivity testing. However, don’t start ringing up the lab to ask for a genome sequence just yet, since the real cost is for the analysis, which is still labour intensive. However, it points the way to the future, which has clearly now arrived, and is changing the way we think about S. zooepidemicus and infection in the horse.
Hide the kids’ toys, tune up the carpet cleaner, get ready for some sleep deprivation… there’s a new dog in the house. Last night, the yet-to-be-named ("he who shall not be named" having been rejected by Heather) little yellow critter arrived. Meg (the existing dog) seems relatively content, or at least resigned. The cat... not so much, but he's already established who's the boss.
So, while I'm momentarily not trying to convince the puppy to pee outside, I’ll take this opportunity to hopefully practice what I preach and describe what we’re doing for things like vaccination, deworming and other infectious disease-related topics.
To start things off: What’s the deworming plan?
- Roundworms (Toxocara canis) are the main concern in puppies. It’s generally a good idea to assume that a young puppy has roundworms, regardless of from where it came and how well cared for it was.
- Canadian parasite treatment guidelines are to treat puppies with a drug that will kill Toxocara worms at 2, 4, 6 and 8 weeks of age, then monthly until 6 months of age. Our little guy is 9 weeks old and has already been treated a couple of times for roundworms, plus he's had one treatment for coccidia (a different parasite that was found on a recent fecal exam). He’ll get another dose of pyrantel pamoate in the next day or two, then monthly until he’s 6 months old. (If someone gets a puppy and it hasn’t been treated like this or its vaccination history isn’t known, it is recommended to give 3 treatments 2 weeks apart, then monthly until 6 months).
- A fecal exam will be done on the puppy in the near future. It’s not an emergency since it won’t impact what I do at the moment in terms of treatment, but it’s good to see if there are any parasites that aren’t killed by the chosen dewormer (e.g. tapeworms) and to detect resistant parasites (i.e. Toxocara eggs still found in feces after appropriate treatment).
- No flea treatment now since he doesn’t have any evidence of a flea infestation and it’s not very likely he’ll be exposed to fleas before the spring based on the current climate where we are.
- No heartworm treatment until the spring either. The Canadian Parasitology Expert Panel (CPEP) recommentaion is for dogs to receive monthly heartworm preventive treatments beginning at a maximum of two months of age. So, I’m not really following that one, but given the time of year, the low prevalence of heartworm in the area he's from and the fact that the puppy wouldn’t have had too much risk of mosquito exposure because of its age and indoor housing, the risk of heartworm exposure this season is very low.
More updates to come, and hopefully not too many descriptions of how to clean puppy feces off of various surfaces.
At the recent 9th International Conference on Equine Infectious Diseases (EIDC) in Lexington, Kentucky several sessions were focused on parasite control of horses. Drug resistant parasites are a world-wide problem in equine establishments, and it has become a challenge to define a simple and useful set of guidelines to be used by horse owners. As many readers of the Worms & Germs Blog will be aware, there is no longer a “one size fits all” program, and parasitologists instead often talk about the complexity related to the different parasites that often infect the horses in concert, their interactions with their hosts, and how to interpret fecal egg counts. While this is all useful and important information, it can be frustrating when it does not readily come with some practical guidance.
Equine parasitology is rarely well-represented at parasitology conferences. Usually, there are less than a handful equine abstracts, and often not even enough for a separate session. The three or so participating equine parasitologists often have to create their own little scientific session over a cup of coffee during the breaks. The EIDC was much different. It had participation from leading equine parasitologists from Sweden, Denmark, Finland, Germany, United Kingdom, Canada, Brazil, and the USA. More than 30 parasitology abstracts were presented at the meeting, and a special session critically addressed the most pressing research needs for equine parasite control. During the conference, an international equine parasitology consortium was formed, and it will serve to coordinate future research efforts and to communicate consensus-based guidelines for parasite control.
So, what are these recommendations then? New research presented at the EIDC illustrated very well that general recommendations are more straight-forward than often anticipated. Work performed by Kurt Pfister and colleagues in Germany illustrated that fecal egg counts are useful for monitoring and controlling parasite transmission by the means of selective therapy. Two Danish studies illustrated that one or two yearly strategic treatments applied to all horses are advisable to effectively break the life cycle of large strongyles, particularly the bloodworm, Strongylus vulgaris. In other words, a basic foundation of treatments can be defined, upon which the some of the more parasitized horses can be identified to receive additional treatments with a selective approach. Several presentations underlined the need for yearly routine evaluations of the efficacy of the anthelmintic drugs used on each farm. The fecal egg count reduction test is the most important use of the fecal egg counts. [Weese comment: that's when you do a fecal egg count before and after deworming, and compare the egg counts to see how much they dropped, as an indication of how well the dewormer worked] Perhaps most encouraging was the promising new diagnostic tools presented by several groups for detection of migrating or encysted parasite larvae. These will turn very useful for identifying horses at risk of disease and in need of deworming. One of these, developed by Jacqui Matthews and her group at Moredun Research Institute in Scotland shows great promise for measuring burdens of small strongyle larvae (cyathostomins), which can pose a threat for severe parasitic disease. With these new tools in hand, we will become able to further refine our recommendations in the future.
More from the International Conference on Equine Infectious Diseases, this time from guest blogger and bacteriologist-extraordinaire, Dr. John Prescott of the University of Guelph:
Stellar work on understanding strangles and Streptococcus equi subspecies equi was presented at the Ninth International Equine Infectious Disease conference in Lexington, Kentucky. Researchers at the Animal Health Trust in Newmarket, United Kingdom (Andrew and Carl Robinson) are working with Matthew Holden at the Sanger Centre in Cambridge to use NextGen sequencing to understand better the strangles bacterium, and the impact of the carrier state on the pathogen as it lurks in the guttural pouch. The abstracts of their work are freely available through the conference web site, http://www.eidc2012.com/.
A novel quantitative PCR (qPCR) based on two unique genes of S. equi was was described that will identify S. equi within 2 hours, with a sensitivity of 93% and specificity of over 96%. Not only is it more sensitive than culture but it also overcomes the effects of non-S. equi contaminants which can interfere with culture. Another development reported was an ELISA based on two antigens unique to S. equi that together have a similar sensitivity and specificity to the qPCR. Current thoughts are that the ELISA could be used as a serological test in screening for carriers, with the qPCR then being used on guttural pouch aspirates to confirm the carrier state, which would then be treated.
The strangles (equi) subspecies of S. equi has been thought to be genetically and immunologically identical, but sequencing the M protein SeM gene has shown that there are over 100 strains. Holden and his colleagues have used high throughput sequencing to characterize the genomes of an astonishing 240 isolates from different countries, including one strain from Canada. They have found that genomic diversity is even higher than SeM sequencing had suggested. As a result of this work, they identified a “fitter” clone (ST151) now spreading through the UK population at the expense of an older clone (ST179).
Most interestingly, they have identified the genetic changes occurring as outbreak strains adapt to their different life in the guttural pouch, which is where the organism hangs out in carrier horses. The adaptation involves discarding some genes, stopping the expression of others, but also duplicating others. According to Holden, a Sanger Centre genome veteran, the S. equi genome is more dynamic than any of the other pathogens with which he has worked. The big question is of course the impact of this adaptation on virulence, and the extent and speed with which these genetic adaptations can be reversed if and when the “carrier“ strains revert to cause acute strangles. There is a horrible suspicion that some may be able to borrow back the deleted genes from other S. equi strains in the guttural pouch.
Because of both its species- and niche-adaptation, strangles has all the characteristics of a bacterial infection that can be eradicated. The superb work being done at the Animal Health Trust, all based on genomics, is drawing the noose ever tighter around this ancient scourge of the horse.
- John Prescott, Department of Pathobiology, University of Guelph
Two presentations at the International Conference on Equine Infectious Diseases yesterday discussed equine coronavirus and whether it might be a new or previously unrecognized cause of disease in adult horses. This follows a presentation the day before that mentioned coronavirus diarrhea in racing draft horses in Japan - a rather unique group, pictured at right.
Dr. Nicola Pusterla from the University of California Davis described five suspect outbreaks in boarding facilities from four US states. Seventy-three (73) horses were affected overall, with decreased appetite being the most common sign in affected horses, followed by lethargy, fever, soft manure and colic. Equine coronavirus was detected in the vast majority of sick horses but rarely from healthy horses at the same facilities. Most horses got better without specific treatment, but five horses died or were euthanized. Overall, the attack rate on farms was high but the death rate was low. Fortunately from an infection control standpoint, infected horses only shed the virus for a short period of time (a few days), making control easier.
Dr. Ron Vin followed this presentation with a description of coronavirus involvement in sporadic disease and outbreaks in adult horses from a variety of US states, most often with mild diarrhea and low white blood cell counts. As with the first report, disease severity was usually less than what we see with some other causes of diarrhea in adult horses, such as Salmonella and Clostridium difficile.
One thing that’s not clear is whether this virus is truly a cause of disease or something that’s just being found in horses that have some other undiagnosed disease. No other potential causes were identified in most of the suspected coronavirus infections, but a large percentage of cases of diarrhea that we see go undiagnosed because we don’t know all the possible causes. It’s certainly possible that there was another cause, but these results suggest that equine coronavirus is something for which we should be looking out when we see gastrointestinal (e.g. colic, diarrhea) or non-specific disease (e.g. off feed, lethargic with no other particular signs), especially during outbreaks. The story may be different in foals, since shedding of the virus by healthy foals isn’t uncommon.
Photo credit: http://newshopper.sulekha.com/
I’m at the International Conference on Equine Infectious Diseases in Lexington, Kentucky at the moment, and will try to write about some of the highlights. One interesting discussion yesterday was about canine and equine influenza. It’s well established that canine flu (A/H3N8) originated in horses and subsequently became established in dogs. Canine flu virus is closely related to, but different from, its equine flu virus parent. That raises questions about whether canine flu virus could be transmitted back to horses. The question has significant implications for what should be done with dogs that might have canine flu that may have contact with horses, and for canine-horse contact in general, especially with performance horses.
A study by Yamanaka et al. (Acta Vet Scand 2012) looked at dog-horse infectivity of canine flu by putting infected dogs in stalls with healthy horses for 15 days. All dogs were sick and shedding canine influenza virus, but none of the horses got sick, shed the virus or mounted an antibody response. This study only involved three horse-dog pairs, so we have to be careful that we don’t go too far with the conclusions, but it suggests that while canine flu started off as horse flu, it has changed enough that infected dogs aren’t much of a risk to horses.
But... (yes, there’s usually a "but" with infectious diseases) dogs are susceptible to "normal" equine influenza. It’s uncommon, but dogs can be directly infected from horses with the classical equine H3H8 flu virus. In such a situation, dogs might pose a risk to horses because they are carrying the equine virus, not the adapted canine version.
- If a dog has influenza that is known to be non-horse associated (i.e. typical canine flu) then there’s probably little concern for horses.
- If a dog has influenza and there’s no clear dog link (or there’s a link with infected horses), it’s reasonable to assume that the dog could transmit the virus to horses.
However, why take the chance? It seems logical to ban any dog with a suspected respiratory infection from horse barns. It also makes sense to ban dogs from barns with equine flu cases. It’s an easy, cheap, minimally disruptive and potentially useful flu control measure that might help reduce transmission of this important virus in both directions.
In response to an equine herpesvirus type I (EHV-1) outbreak at Hawthorne Racecourse in Illinois, the Ontario Racing Commission (ORC) announced movement restrictions on horses from Hawthorne, and Illinois in general.
- Any horse that has been on the grounds at Hawthorne since Oct 4 is not allowed on any Ontario racetrack until 30 days after Hawthorne's quarantine is lifted
- All horses from Illinois being shipped into the Woodbine or Fort Erie racetracks must come with a certificate that states "Horses represented on this Certificate of Veterinary Inspection have not originated from a barn or premises that is under quarantine for herpes virus, nor have been exposed to a confirmed or suspect case of herpes virus, nor have shown clinical signs suggestive of herpes virus, nor have been febrile within the previous three weeks."
All other tracks are also advised to be cautious about accepting horses from Illinois, but restrictions are at the discretion of individual facilities. The ORC is also recommending that all horses from Illinois are examined and their temperatures are taken prior to being admitted to any track.
Basic physical examination and body temperature checking can be great infection control measures when used on a routine basis. Too many sick horses make it onto tracks, show grounds and into sales, and while checking temperature is by no means 100% protective, it's an easy, cheap and a quick way to identify potentially infectious horses. Yet, it doesn't happen. Considering the potential implications of a single infectious horse making it onto a track, it doesn't make sense that more effort isn't put into routine practices like these. Yes, it would take a couple minutes, but if it prevents one infection (let alone an entire outbreak), it's worth the minimal effort.
As an aside, I've always been baffled why places like yearling sales won't consider employing such measures - well, maybe not baffled because sending sick horses home costs the sale money. But considering how common infectious diseases are in horses after sales, it's hard to understand why buyers are not pushing sales to do what they can to make sure buyers aren't spending big money on damaged goods, i.e. sick horses. I'd like to think that a sale could make it a great marketing point by touting their strong infection control program to convince buyers to come and spend their money with less chance of getting a sick horse.
It's always hard to say what the best approach is for handling EHV infections. On one hand, it's a very common virus that is lying dormant in the bodies of a large percentage of healthy horses, everywhere. On the other hand, we certainly know outbreaks of serious disease happen and horse-horse contact and movement of horses helps outbreaks spread. These Ontario restrictions are pretty straightforward and common sense, but thought should be given to what other measures can be taken on a routine basis to help reduce the risk of EHV-1 outbreaks from developing in Ontario, and to control the numerous other infectious diseases that affect more horses every year.
People sometimes get freaked out by the concept that they have approximately 10-times as many bacterial cells on them as all their own body cells combined.
- Yes, our cells are a minority in our own bodies, and amongst the trillions of bacteria we carry are many that could kill us given the opportunity.
Yet, we have somehow managed to survive, both individually and as a species. So, keeping things in perspective is important and, in reality, we need much of that bacterial population to keep us healthy.
Just like every person is carrying many bacteria on any given day that can cause illness or infection, every animal is carrying many different microorganisms that can infect a person. While infections from pets do happen, they are uncommon - we're not seeing dog owners dropping like flies on the street, which is a testament to our immune system and other body defenses and barriers (e.g. intact skin).
So, when studies come out describing various bugs at various sites in various animals, you have to put them into context. It's not that the studies are bad (my lab does a lot of work trying to define the complex bacterial populations of sites like the intestinal tract, oral cavity, respiratory tract and skin), it's that we need to think about what the results really mean and avoid sensational headlines in the press.
A recent paper in the Archives of Oral Biology (Yamasaki et al. 2012) is an example of this. The study looked at mouth bacteria in dogs and their owners. They used molecular testing developed for human oral samples and focused on bugs that have been implicated in dental disease - not the range of bugs that are more often associated with zoonotic infection. Not surprisingly, they found lots of different bacteria in the mouths of the dogs, including some bacterial species that were present in both dogs and their owners. No methods were used to type the bacteria to see whether the strains found in dogs and people were the same or whether dogs and people just normally have those bugs present, independently, in their mouths. However, we know that transmission of certain bacterial between people and their pets is a relatively common event, and it wouldn't be surprising if the same applies for oral bacteria, through direct contact (e.g. kissing/licking) or through indirect contact (e.g. a person touching a dog's face then his/her own face).
So, this was an interesting study... nothing earth-shattering but the first side-by-side comparison of oral microflora in people and dogs, and it provided some useful information for future research. The authors rightly discuss the limitations and things that need to be done to further investigate this, such as looking at strains and evaluating the bacterial population in relation to types of contact that people and dogs have (e.g. do certain activities increase the likelihood that people and pets share oral bacteria). They conclude by writing "In summary, we found that the distribution of periodontopathic bacterial species in dogs and their owners is diverse, though several species including P. gulae may be transmitted during close daily contact. Therefore, our findings could be significant in understanding the relationship between the oral health of humans and their companion animals"
Yet, headlines like "New study warns against kissing your dog" don't really reflect the true content... not uncommon but unfortunate.
I get asked about dogs licking a lot. My general line is that I don't particularly like to be licked but for the average healthy person, I don't get worked up about it. My kid were playing with puppies yesterday and were getting licked. I didn't fire up the power washer to hose them down after. If I had an infant, an immunocompromised child or some other high risk person it would be a different story. Licking around the ears is something I like to see avoided because of some links between this activity and certain ear infections in kids, but overall it's a relatively low risk situation that some people enjoy.
When I give talks about methicillin-resistant staphylococci, I almost invariable get into a discussion of the risks of methicillin-resistant S. pseudintermedius (MRSP) in people. This bug is becoming increasingly common in dogs and because it's so resistant to antibiotics, there's concern about whether it can be transmitted to people.
My usual answer is that there is a low risk of MRSP infection in people, but not no risk. MRSP is no more likely to cause an infection in a person compared to it's antibiotic-susceptible counterpart, regular S. pseudintermedius (the resistant version is just harder to treat). Most dogs carry susceptible S. pseudintermedius in their mouths, nose, skin, ears and/or intestinal tracts, so people in contact with dogs are very commonly exposed. Yet, human infections seem to be quite rare. There are periodic reports in the medical literature about S. pseudintermedius infections in people, but they tend to be single case reports, and when someone can publish a report of a single infection in person, you know it's pretty uncommon (since if it was common, no journal would be interested).
That's my long-winded way of introducing a recent case report in the Journal of Clinical Microbiology (Hatch et al. 2012). The patient in the report was an elderly man with underlying disease, so someone who was at high risk of infection from bugs that don't often affect otherwise healthy people. He had skin lesions, sore joints and a bloodstream infection, and "S. intermedius" (I'll get to the name issue later) was isolated from his blood. Fortunately, he was successfully treated. He owned a dog and that was (reasonably) considered to be the source of the bacterium, but no testing was done to look into that. So, from a disease standpoint, it's not really a surprising case - just another in a series of very rare infections that have happened.
The other issue here is the fact that the authors (along with the diagnostic lab, the journal's reviewers and the editor) are behind the times and don't realize that it's virtually guaranteed that this person didn't have a S. intermedius infection. Rather, it was presumably S. pseudintermedius, or perhaps another similar staphylococcus. It wouldn't have much of an impact on this particular case, although not knowing the species probably also indicates the lab doesn't know that there are different breakpoints to determine if the bug is methicllin-resistant, and there's the potential they would miss methcillin-resistant S. pseudintermedius and use an inappropriate and ineffective treatment (fortunately that didn't happen here).
I've had a few (well... more than a few) calls about potential risks to animals from the large Canadian E. coli O157 beef recall. The main concern is for dogs that are fed potentially contaminated raw meat that has been recalled, but there is also potential for exposure through cross-contamination if people in the household consumed any suspect products, and through dogs getting into garbage containing meat packaging. The other issue is whether dogs and cats can become exposed, start shedding the bacterium in their feces and subsequently infect people. Contamination of a pet's food bowl leading to human exposure is also a potential concern, especially considering the fact that as few as 10 of these E. coli bacteria can cause infection in people.
Overall, these risks are quite low. The contaminated meat is primarily a human concern. The role of E. coli O157 in disease in dogs is pretty unclear, but there's no evidence it's a significant problem. Experimentally, disease can be induced in dogs fed relatively high numbers of E. coli O157, but natural disease seems to be rare (including in dogs on beef farms where exposure is probably relatively common). I think it's reasonable to suspect that this strain of E. coli can cause disease in dogs, but it doesn't happen very often. We also don't recognize hemolytic/uremic syndrome (HUS) in dogs (the severe form of E. coli O157 infection that can cause kidney disease in people).
The risk to people from recalled meat is real. The risk to people from pets is pretty remote. Studies have not identified pet contact as a risk factor for human E. coli O157 infection. Dogs have been implicated as vectors in a limited number of specific household situations, albeit with rather weak evidence and only when focused on people and animals on beef farms.
Overall, the risks to pets and from pets are pretty limited. The main concern with the recalled meat is human disease. That being said, I wouldn't recommend people feed recalled meat to animals instead of disposing of it, since there is a possible though slight risk to both humans and animals.
A Wyoming (USA) dog has died of necrotizing fasciitis (more popularly and dramatically known as "flesh-eating disease"). This isn't unheard of in dogs, but it's a pretty rare disease. The six-year-old Great Dane's infection apparently raised some concern because of the diagnosis of necrotizing fasciitis in three people in the area. However, there is no known connection between the dog and the human cases.
While not anything new, the case is noteworthy for a few reasons, not the least of which is the high mortality rate associated with this disease. A few different types of bacteria can cause "flesh-eating disease," but streptococci are most common. The news reports say the dog had Group A strep, which is quite surprising and raises a lot of questions, such as:
- Was it really Group A strep? Most of these infections in dogs are caused by a related bug, Streptococcus canis, which is a Group G strep. Group A strep is essentially unheard of in dogs and I have to wonder whether the bacterium was misidentified by the lab or the reporting is inaccurate.
- If it actually was Group A strep, what's the public health concern? Group A strep is a common bug in people (the one that causes strep throat) but invasive infections like necrotizing fasciitis are a much bigger concern, and potential dog-human transmission would have to be considered.
- If this was Group A strep, are public health authorities taking the same steps was they would in response to finding Group A strep necrotizing fasciitis in a human in the household (such as the Public Health Agency of Canada's Guidelines for the Prevention and Control of Invasive Group A Streptococcal Disease?) This would make sense to me.
- If this was really Group G strep (the most likely scenario), did the dog receive a fluoroquinolone antibiotic before the infection set in? It doesn't sound like that was the case from the article, but knowing for sure would be interesting. Most cases of Group G strep necrotizing fasciitis that we see are associated with enrofloxacin treatment of an initially mild infection, since this drug can induce increased virulence in Group G strep.
Regardless of whether it was Group A or Group G strep, it's an unfortunate situation for the dog and the family, but people shouldn't be too concerned because this is a very rare, sporadic disease in dogs and one that has not been linked to any risk to other species.
Earlier this year, a troop of Boy Scouts in the US beat off a rabid beaver that was attacking their leader (I wonder if there's a badge for that). Boy Scouts and infectious diseases are in the news again, but not with as happy a story.
In the recent incident reported on ProMED, ten Boy Scouts that attended a camp on the banks of the Semois River in Belgium developed leptospirosis - a potentially severe bacterial infection caused by Leptospira bacteria. The bacteria are shed in the urine of a variety of animal species, and people can become infected through contact with contaminated water or animals. The boys reported having played with a rat, which was likely actually a muskrat, based on the description of its size.
Three of the boys were hospitalized. Hopefully all are on the way to recovering.
This is yet another reminder that wildlife should be left alone. It's possible the boys were infected from the environment, but handling a muskrat (which was presumably sick if they were able to get that close to it) certainly increases the risk of exposure to a variety of infectious diseases.
Image of a North American muskrat (photo credit: Linda Tanner)(click image for source)
.Dirofilaria immitis is the parasite that causes heartworm in dogs (and rarely cats). This mosquito-borne parasite can cause serious disease in dogs, and a lot of effort is spent trying to prevent heartworm infection. It can also cause disease in people who are bitten by a mosquito that has fed on an infected dog, but human infections are quite rare and of limited health risk. The main concern with regard to human infection is that it can create a small mass in the lungs. The mass itself isn’t usually a problem, but if it gets seen on an x-ray, it may appear very similar to a lung tumour, potentially leading to the use of more invasive diagnostic techniques (e.g. lung biopsy) to rule out cancer.
Dirofilaria immitis is not the only species of Dirofiliria. In fact, there are mulitple different Dirofilaria species with different hosts, some of which can also rarely infect people.
When it comes to dogs, D. immitis is the main concern, but dogs are also the host of Dirofilaria repens, which is most common in Mediterranean countries, eastern Europe and sub-Saharan Africa. Now, there’s a new one to add to the list, based on a paper in the Journal of Clinical Microbiology (To et al. 2012) that describes a novel Dirofilaria species in Hong Kong. Interestingly, it was found first by identifying disease in people.
Three human cases were identified in Hong Kong over a 10 month period in 2011-2012. When the researchers recovered the parasite from these individuals, they determined that, while it looked like other Dirofilaria, it was genetically different from any known species. They have tentatively named it «Candidatus Dirofilaria hongkongensis» (not very original but descriptive).
They then tested blood samples from 200 dogs and 100 cats, and found a parasite in six dogs that was identical to the new Dirofilaria from the human patients. They also tested the dogs with a commonly used commercial heartworm test that detects D. immitis and they were all negative, except for one dog that was actually infected with both the new species and D. immitis.
This is an interesting report and shows the need to be aware of potentially emerging issues. Some important questions need to be answered:
- What’s the risk to people? Obviously it can cause disease, since the three people in this report were actually sick. However, is this a very rare condition or something that may be more common? Is it something that’s been around for a long time and not diagnosed or is it really new?
- How do people get infected? They presumably get it from being bitten by an infected mosquito (as for other Dirofilaria) but how does the mosquito get infected? Are dogs the main source, one of many sources or are they inconsequetial?
- Does this new Dirofilaria cause disease in dogs? The six positive dogs were healthy, at least at the time of testing. Heartworm caused by D. immitis is a gradually progressive disease, meaning the signs become worse over time, so the fact that these dogs were clinically normal doesn’t mean there’s no risk, as they could start showing signs later on.
- What is the risk outside of Hong Kong? It’s hard to say because we know so little about this parasite, but it’s probably limited, at least at this point in time.
I’ve written about lymphocytic choriomeningitis virus (LCMV) before, as an interesting but pretty uncommon rodent-associated disease. Human infections are mainly associated with handling rodents, although other routes of transmission, such as organ transplantation from an infected donor, have also been reported. Being a disease associated with rodents and considering how rodents are produced in North America (i.e. mass production in large breeding colonies, followed by transportation to large distributors and massive mixing of animals), LCMV is bound to be a recurring problem associated with the pet rodent trade.
An issue of the CDC's ominously titled Morbidity and Mortality Weekly Report describes the risk of infection with LCMV to people who work in rodent breeding facilities. It all started with the diagnosis of meningitis in a person who worked in a rodent breeding facility in Indiana. An astute doctor suspected LCMV and the diagnosis was confirmed. The breeding facility was a pretty large one, housing approximately 155 000 (!) mice and 14 000 rats. An investigation of facility personnel ensued and approximately 25% of employees had antibodies against the virus, indicating previous infection. A large percentage of the workers reported having had signs consistent with disease (e.g flu-like illness), indicating that they were likely infected and not just exposed.
Considerable effort was put into testing the animals. Of over 1000 animals tested, 21% of mice had detectable levels of the virus in their bodies. That’s pretty impressive and concerning, both for employees and anyone receiving animals from this facility.
In response to this investigation, all mice at the facility were euthanized, and the facility was thoroughly cleaned and disinfected.
This report highlights the risk of exposure to LCMV for people who work with rodents, especially in large facilities such as this. It also highlights the risks posed to people buying rodents from these facilities, which also includes other diseases in addition to LCMV. Good general hygiene and infection control practices should greatly reduce the risk of LCMV transmission to rodent owners. In particular, efforts should be directed at new rodents, since LCMV shedding is probably greatest during the initial period after an animal enters a household or other facility. Virus shedding it often transient, and once they get out of the high-risk facility and become acclimatized to their new home, shedding rates in these rodents probably decrease over a short period of time. Overall, the risk of LCMV in someone with a pet rodent is low, but these basic preventive practices are easy to do and make a lot of sense.
Photo: Female mouse with her litter. (Photo credit: Seweryn Olkowicz) (click image for source)
When bacteria containing NDM-1 (New Delhi metallobetalactamase 1) were first identified a few years ago, I talked about it during presentations as something bad that's coming our way. NDM-1 is an enzyme that gives the bacteria that possesses it resistance to a huge range of antibiotics, to the point that few or no viable treatment options are available. Given the close relationship between animals and humans, I figured it was only a matter of time before cases were identified in animals, especially household pets. A presentation by an FDA researcher at the 2012 Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) has confirmed the finding of NDM-1 in E coli from a pet cat in the US. I can't take much credit for foresight because it was pretty predictable, but it re-affirms concerns about emerging diseases and how infectious pathogens can move between people and animals.
Not much is known about this current case, since the E coli isolate was submitted for testing as part of a large ongoing surveillance study by Dr. Dawn Boothe of Auburn University. At this point, it's unclear whether the cat had been on antibiotics earlier, whether the owner had been diagnosed with the infection, whether the owner had traveled to areas where this bug was first found (e.g. India), and other relevant pieces of information remain unknown (or at least unreported).
The cat was positive for the NMD-1 E.coli on multiple samples. The most intriguing aspect of this case is the fact that the culture samples from the cat were collected in 2008 and 2009 - at least a year before NDM-1 was first identified in the US. That's strange and concerning, and raises lots of questions about where this super-E.coli originated.
Some possible origins of the NMD-1 E.coli in this cat include:
- The owner may have traveled to an area where the bug was present, became a carrier and spread it to his/her cat upon returning home.
- The owner could have been infected when traveling, but it the infection may have been minor such that it didn't require medical care or a culture wasn't taken (so no one knew it was being caused by a super-bug), and subsequently the owner passed it on to the cat. (Remember that NDM-1 is a major concern because very few antibiotics are effective against it. However, the enzyme doesn't make the bacterium that carries it inherently more able to cause disease, so minor infections are possible.)
- On ProMed, the moderator stated that he believes stowaway rodents from India or Pakistan likely carried the bug to the US and spread it amongst other rodents, with eventual exposure of the cat through catching an infected rodent. It's possible but it's a major stretch, in my opinion.
- Perhaps the cat came from one of those endemic regions. That's pretty unlikely but there's a lot of animal movement around the world, with very little regulation, so it is possible.
We may never know how this cat got infected, but this case should be a reminder that we need to pay attention to animal populations in parallel with the human population. I keep saying it, but getting action has been difficult. People like to talk about "One Medicine," but actually getting people to practice "One Medicine" has been easier said than done.
a) there are more rabid beavers these days,
b) rabid beavers have always been around in these numbers but they have recently acquired a taste for human flesh, or
c) it's just a fluke,
The latest incident involved a beaver in West Springfield, Virginia that chased after some kids at a nature centre. The kids had been swimming and saw a beaver swimming towards the dock. It's not that unusual to see beaver's swimming around in some areas, but like most wildlife, they typically stay away from people. Not this one though. It "leaped out of the water onto the dock, acting aggressively and chasing the children." Police shot the animal and testing confirmed it was rabid. Presumably, no one required post-exposure treatment since there were no bites.
While rabid beavers are rare, this and earlier incidents involving attacks by rabid beavers, otters and other critters highlight some basic principles regarding rabies safety:
- Stay away from wildlife.
- Mammalian wildlife that are acting abnormally, including displaying no fear of humans, should be considered rabid until proven otherwise.
- Any bite by a wild mammal should be considered a potential rabies exposure. The animal should be tested whenever possible and if it can't be shown that the animal wasn't rabid, it must be assumed that there was rabies exposure.
Common sense goes a long way toward avoiding rabies exposure, but sometimes it's not avoidable. Knowing what to do in the event of a bite from a wild and potentially rabid animal is important. The key is involving physicians and public health personnel who understand rabies exposure risks, so that a proper risk assessment can be done and treatment can be started promptly if it's indicated.
Image: A North American Beaver (Castor canadensis), by Laszlo Ilyes (click image for source)
If you ask people about tapeworms, they typically think about the "ick" factor of having a large worm in their gut, but they probably don't get too concerned. However, some types of tapeworm infection can be serious health problems in humans and animals. One of the worst is infection by the tapeworm species Echinococcus multilocularis. A couple of recent reports about E. multilocularis in Canada have received a lot of attention.
With Echinococcus, the problem isn't the worm living in the intestine. Adult worms live in the intestinal tract of only "definitive hosts," which are primarily foxes and coyotes in North America. The worms aren't necessarily a problem for these animals, but they can pass large numbers of tapeworm eggs in their stool. The parasite's normal life cycle continues when small animals (e.g. rodents like mice and voles) swallow a tapeworm egg. The parasite then develops into a cyst in the animal's body, and if/when the little critter is eaten by a fox or coyote, the cyst gets eaten too and the fox/coyote develops a new adult tapeworm in the intestinal tract.
When it comes to people (and some other domestic species), the problem is what happens when they ingest tapeworm eggs. Like in rodents, the eggs hatch and the immature parasites migrate through the intestinal wall, and can then spread to virtually any place in the body. They can then develop into large cysts that, over a long period of time, result in serious disease. Large cysts and/or cysts in critical areas (e.g. the brain) can be devastating. Treatment is difficult, prolonged and expensive, and death rates are high.
Dogs are a bit of an oddity in this cycle, since they can carry adult tapeworms (not surprising, since they are similar to foxes and coyotes) but they can also get these large tissue cysts. From public health and infection control standpoints, dogs shedding Echinococcus eggs are the main concern, but cysts are potentially devastating in the rare dog that develops one, just as they are in people.
Recent concerns revolve around two papers, one that described a dog from British Columbia with Echinococcus cysts (Jenkins et al. Emerging Infectious Diseases 2012) and a study that identified E. multilocularis eggs in feces from 23/91 (25%) urban coyotes in Alberta (Catalano et al. Emerging Infectious Diseases 2012).
What's the risk in Canada?
It's low. Actually it's very low, and there have been only a handful of cases diagnosed even in people in North America. But with a serious disease like this, you can't ignore it. If Echinococcus is spreading in coyotes and foxes, it creates the potential for exposure of other species (including humans). The risk gets higher as coyotes and foxes get closer and closer to people and dogs, as is happening in some areas because of urban sprawl. The more coyotes that are around and the closer they are to human populations, the greater the chance that a person or dog will inadvertently ingest a tapeworm egg from coyote feces. Dog parks may be of particular concern because of the high traffic through them and the potential for them to be a big mixing site between wildlife, pets and humans.
There shouldn't be any panic because of this, as it still remains an extremely rare disease. But, it's not much consolation that it's a rare disease if you're the one with a big Echinococcus cyst in the brain. So, while the risk is low, we don't really know (yet) whether it's changing, and it's worth using some basic practices to reduce the risk. These include:
- The standard: Don't eat poop. Pretty straightforward but easier said than done, in many respects, since fecal contamination of the environment is pretty common. Avoiding inadvertent ingestion of feces can be done through proper handling of dog and wildlife feces and attention to handwashing.
- Controlling rodents and preventing pets from catching and eating rodents.
- Preventing dogs from eating wildlife feces.
- Routine tapeworm deworming should kill Echinococcus and if a dog is at particularly high risk, more regular testing and treatment for tapeworms may be indicated. Not many dogs fit into that category at the moment, though.
Image: Echinococcus multilocularis isolated from a fox in Hungary. Unlike the very long tapeworms of the Taenia genus, which are most commonly found in dogs and cats, Echinococcus tapeworms are quite small (the bar in the picture is 0.5 mm), but the eggs shed in the feces of animals with an intestinal infection (involving mature adult worms) are virtually identical to those of Taenia spp. (click image for source).
The annual US rabies surveillance report has been published in the latest edition of the Journal of the American Veterinary Medical Association (Blanton et al 2012). There's not really anything earth-shattering in it, but it's a good overview of the rabies diagnoses in the US from 2011. As always, it only provides a peek into rabies in wildlife (since only a small percentage of wildlife with rabies get diagnosed and reported) but numbers and trends in domestic animals, along with general wildlife data, provide useful information about the state of this virus in the US. Among the highlights:
- Rabies was diagnosed is 6031 animals and 6 people, from 49 states and Puerto Rico (Hawaii remains rabies-free). This is a 2% drop in animal cases from 2010, but I don't put much stock in that because the numbers are weighted towards wlidlife cases, and it's hard to have confidence in year-to-year numbers of rabid wild animals (because it's so dependent on what actually gets tested).
- The main wildlife species that are involved in maintaining the rabies virus in the US (reservoir species) continue to be raccoons, bats, skunks and foxes on the mainland, and mongooses in Puerto Rico. The relative importance of these species varies between regions.
- Raccoons were the most commonly affected species, accounting for 33% of all rabid animals reported. Other leading species were skunks (27%), bats (23%) and foxes (7%). Less common species included coyotes, bobcats, javelinas, deer, otters, mongooses, wolf hybrids, groundhogs and beavers.
- Cats were the leading domestic animal, with 303 diagnosed cases. Dogs came in next with 70, followed by cattle (65), horses (44), and goats and sheep (12). There were also single cases in a domestic bison and an alpaca.
- The six human cases represent the highest annual number of cases since 1994, if you exclude 2004 where four cases were associated with transplantation of organs from a single infected person. In a review of the 24 domestically-acquired human cases from 2002-2011, 88% were linked to bats.
- Three of the six 2011 human cases were acquired outside of the US; one each from Haiti, Afghanistan and Brazil - and all from dogs.
- Two of the three domestically-acquired cases were associated with bat contact. The source of the remaining case, an eight-year-old girl, is unknown, but contact with cats from a feral colony near the girl's school is a possibility.
- 5/6 people with rabies died. That's actually an impressive survival rate, since any survival is still a very noteworthy event when it comes to rabies. The survivor was the eight-year-old girl, and she apparently has suffered no longterm cognitive impairment.
Interestingly, we get a good synopsis of Canadian rabies data in this report too:
- 115 rabid animals were identified, with 92% being wild animals.
- There were three rabid livestock (two of which were horses) and six dogs and cats.
- No rabid raccoons were identified, continuing a trend started in 2009.
And regarding rabies in Mexico:
- 148 rabid animals were identified, mainly cattle (82%).
- Rabies was diagnosed in 20 dogs, with evidence that the canine rabies virus variant (which has been eliminated from Canada and the US) is circulating in some regions.
- There were three humans cases: two acquired from vampire bats and one from a skunk.
The Guelph Humane Society has re-opened after a temporary closure to manage a potential ringworm outbreak. The shelter took an aggressive, proactive approach to the issue, including testing and treatment of all animals and thorough disinfection of the facility.
Looking back on a proactive outbreak response like this one, it's always hard to say if a bad outbreak didn't develop because it wasn't going to, or because of the early aggressive response (i.e. did it get better because of what they did or despite what they did). However, if you sit back and wait (or remain in denial), you can be sure that it's much more likely that badness will develop.
Once things have settled down, people sometimes complain that an aggressive response was unnecessary because nothing bad happened, but they're often the same people that complain that not enough was done when an major outbreak occurs. An ongoing challenge in infection control is fighting complacency, since successful infection prevention and control programs sometimes lead to people forgetting about the bad things that can happen and why such programs are in place to begin with. We should applaud facilities that "suck it up" and accept the negative PR, time and financial consequences of an appropriate response in order to protect the health and welfare of the animals for which they care and all the people (employees and public) who have contact with them.
When I give talks about pet therapy animals, I talk about appropriate and inappropriate animals. On one slide I have a picture of a hedgehog, and I use it as an example of an animal that sometimes makes its way into pet therapy programs, despite standard guidelines to the contrary. This is a species that raises significant infectious disease concerns because hedgehogs can carry an impressive array of microorganisms that can be spread to humans. A big one is Salmonella.
So, it doesn't come as too much of a surprise that the CDC is reporting a multistate outbreak of salmonellosis associated with hedgehogs. Here are the highlights:
- Fourteen infections have been reported between December 2011 and August 2012. There are probably many more because in most outbreaks, only a minority of affected people get tested.
- People have been infected in six states (Alabama, Indiana, Michigan, Minnesota, Ohio and Washington), all with the same strain of Salmonella Typhimurium.
- All 10 people that were interviewed reported contact with hedgehogs or their environments. Considering the rarity of hedgehogs as pets, that's a pretty good indicator that hedgehogs were the source. The outbreak strain of Salmonella was detected in two households, in areas where the hedgehogs lived or were bathed.
- No one has died, but three people were hospitalized.
- As it typical, a large percentage (50%) of affected individuals were children 10 years of age or under.
The fact that this outbreak appears to have occurred over a long period of time and a large geographic area strongly suggests that this might be ultimately traced back to a common breeder or intermediary source. Many small pets like these are mass produced by large breeders and shipped across the country, creating the potential for a problem at a single breeder to have far-reaching consequences in other breeder colonies and in households. This has been shown repeatedly with species like hamsters and mice.
This report doesn't mean that hedgehogs shouldn't be kept as pets. However, hedgehogs do seem to be a higher-risk species than average, and households that include high-risk individuals (e.g. young children, elderly persons, immunocompromised individuals, pregnant women) should probably avoid them. More importantly, the potential for transmission of Salmonella and other pathogens indicates the need for good basic, routine hygiene practices, such as washing hands after handling a hedgehog, keeping them out of the kitchen, not bathing them in kitchen or bathroom sinks, and supervising contact between hedgehogs and kids.
I'm not really sure what to think about canine norovirus. Is it a rare, oddball infection or is it an important, overlooked and/or emerging problem?
- There are only a few reports of norovirus infections in dogs, but I doubt many people are looking for it.
- I've looked for it a few times during outbreaks, but not enough to convince me it's not here.
- Most outbreaks of canine gastrointestinal disease are not investigated, and norovirus testing isn't commonly available.
So, I think it's hard to say much about this bug at the moment.
However, another outbreak report involving canine norovirus (Mesquita and Nascimento, Transboundary and Emerging Diseases 2012) has been published, increasing concern that this might be an overlooked or developing issue. This latest report from Portugal describes an outbreak in a kennel that started after the introduction of some dogs imported from Russia (yet another example of the problems that can occur with dog importation, especially in the absence of good quarantine and infection control practices).
The outbreak started after two dogs from Russia were brought into a Portuguese kennel. Both had diarrhea at the time of arrival (strike 1 - introduction of new dogs, particularly sick dogs, is just asking for an outbreak) and were put into the general dog population (strike 2). Two days later, the other five dogs in the kennel developed diarrhea (not surprising). All were positive for canine norovirus (ok, that's surprising) and within one week, all the dogs appeared to have fully recovered.
There's no mention of whether testing for other causes of diarrhea was performed, but I assume that's the case. The sudden onset, rapid transmission and relatively short, self-limiting course of disease is consistent with norovirus infection.
Canine norovirus has been found in Portugal before, and the virus found in these dogs was very similar to previous Portuguese isolates. Whether that means the dogs acquired the virus in Portugal en route to the kennel or whether this virus is widely disseminated internationally isn't clear (in large part because so few people have looked for canine norovirus).
Much more remains to be learned about this virus. It should be considered in outbreaks of diarrhea in dogs, especially outbreaks involving rapid transmission between animals. A major obstacle to obtaining more information about this pathogen is the general failure to investigate outbreaks in which it may be involved. While outbreaks are often dramatic, testing is usually limited because of the cost. That's especially true when dogs aren't dying. Often, testing for rare or potentially new problems only occurs when there's a complete disaster and/or if an interested researcher or diagnostic laboratory gets wind of it and is willing (and able) to do some testing at no cost. That's not often an option. I do testing as much as I can, but I don't have any money dedicated to outbreak investigation so it depends on whether I have spare resources to put into an investigation at the time.
The risk to people from canine norovirus is not known, but is probably limited. There is some evidence of potential transmission of noroviruses from pigs or calves to people, but the risk from canine norovirus isn't clear. Common sense practices to avoid contact with diarrhea (from any animal) should be used, as much to prevent exposure to the pile of other pathogens that can be in dog poop, as to prevent potential exposure to canine norovirus.
On my way to Beth's soccer practice yesterday, I heard a blurb on the radio about how Frank Klees, MPP (Member of Provincial Parliament) told the legislature that the Newmarket OSPCA was going to euthanize all their animals because of a ringworm outbreak, and that three employees had been fired because they objected to the number of euthanasias. His statement that "We have a repeat now, at the same shelter, of what took place nearly a year and a half ago" was pretty concerning, given the severity of the earlier "ringworm" debacle. Klees, the veteran PC party MPP, has been a vocal critic of the OSPCA in the past.
Later that night, I found a little more information, which was mainly centred around complaints about the number of animals being euthanized for various reasons, and a subsequent statement by the OSPCA that there was no outbreak.
Now, it appears that a protest is being planned for today (Friday), although it's not really clear to me what they are protesting. Maybe there's more to it than is being reported and an outbreak or cull is actually underway. However, in the absence of that, their protest is better directed at the state of the animal population rather than OSPCA euthanasias.
While I don't have a lot of confidence in Newmarket OSPCA management at this point, it's hard to blame the them for euthanizing a lot of animals. It's a function of supply and demand, as well as limited capacity.
North America wide, the euthanasia rate for cats entering shelters is about 50%. That's a staggering number, but it's not usually the fault of the shelter system - it's because of the massive overpopulation of cats. When twice as many cats come in as there are available homes, something has to give. You can either build new shelters every year (obviously unrealistic), pack current shelters to the ceiling with cats crammed into crates in every corner (a perfect situation for a large outbreak and hardly fair to the cats) or euthanize many and focus efforts and resources on the most adoptable animals. As much as the "no-kill" concept has market appeal, it's completely unrealistic for cats at this time because of the simple fact that millions of new cats are born every year with no hopes for a home. A small shelter can run as a no-kill shelter, but that just means that they limit their admissions and/or don't accept cats with limited adoption potential. A large shelter like Newmarket that takes whatever cats arrive will euthanize many of them, even without an outbreak going on. In fact, to do things right, a large shelter has to euthanize lots of cats to allow them to properly care for and find homes for other cats. Sad but true.
So, while euthanasia is obviously undesirable and it gets people worked up, yelling at the OSPCA doesn't do anything. They're not going to stop euthanizing cats, because they can't. Efforts are better spent helping deliver care to stray animals and preventing the cat population from expanding.
One of the most important things anyone can do to help the problem is make sure to (as Bob Barker used to say) have your pet spayed or neutered (and pass the message along to those you know as well!).
An 8-week-old puppy in Van Buren County, Michigan has died from infection by a virus that normally infects horses. This is a rather rare occurrence of a nonetheless devastating infection. The puppy was euthanized after developing seizures and other neurological abnormalities, and Eastern equine encephalitis (EEE) virus infection was ultimately diagnosed. Testing for this and other viruses was probably undertaken because of concerns about rabies.
EEE virus is a mosquito-borne virus that circulates in the bird population and is spread by mosquitoes. Horses are the main victims of infection but disease can occur in various other mammals, including people and dogs.
Canine infections are very rare and this can be considered an "oddball" infection. There's no evidence that dogs are at any elevated degree of risk compared to previous years, but it is a reminder that while infections are rare, dogs can be susceptible to EEE. The puppy's young age probably played a role and certain groups (e.g. puppies, elderly dogs, dogs with compromised immune systems) are presumably at greater risk of illness than the normal dog population. The other obvious implication of this report is that it is clear that EEE is circulating in mosquitoes in the area. That means other susceptible species, namely horses and people, are also at risk of exposure.
EEE in people is pretty high on the badness scale. It's fortunately rare but when it strikes, it's usually fatal. The same is true for horses. There is a vaccine for horses but not for people, so the main protective mechanism for people is mosquito avoidance.
As with EEE in horses, infected dogs pose no real risk to humans. The virus is not spread by regular contact and dogs don't develop high enough viral levels in their blood to be able to infect more mosquitoes (who could then infect people). There's a potential risk of transmission through contact with infected tissues during post mortem examination (necropsies) but standard practices used to prevent transmission of other diseases (e.g. rabies) should be effective for EEE as well.
The Ontario Ministry of Agriculture Food and Rural Affairs has issued a disease advisory to Ontario equine veterinarians about West Nile virus (WNV), but not in response to cases of WNV in Ontario horses. In fact, to date, there have been no reported cases in horses in the province this year. However, no reported cases only means no horses have become sick and WNV infection has been considered and WNV testing has been performed. It doesn't mean that no horses in the province have been infected, and as much as anything else, the advisory is a reminder to be aware of WNV and ensure that potential cases are properly tested.
While not anywhere near as bad as the situation in some US states, Ontario has had a larger than expected number of human WNV infections this year, and it's reasonable to assume that many equine infections have (and will) also occurred. Since the end of August is typically the start of the WNV season in horses in Ontario, the next few weeks will tell us a lot about the state of this disease in horses in the province this year.
- The Indian River Reptile Zoo near Peterborough, Ontario, rushed some of their stock of snake anti-venom to Brantford General Hospital (about three hours away) to aid in the treatment of a woman who had been bitten by a Copperhead snake. Hospitals in Ontario don't tend to stock anti-venom for snakes that don't live anywhere near here, and it's fortunate for the woman that a couple of zoos in Canada stock anti-venom and are willing to share it (and that those zoos happen to be in Ontario and not the other side of the country). Circumstances of the bite aren't clear but the woman or someone she visited a) is obviously keeping a dangerous snake and b) obviously isn't handling it properly. Indian River Reptile Zoo president Bry Loyst sums up some of the problems with snake bites, saying "Hospitals are amazing but they don't have the expertise right there,” and “You'd be surprised at how many venomous snakes there are out there [in Ontario homes].”
- JayJay, a pet macaque (a kind of monkey) from Okeechobee, FL, was shot after "flipping out" and attacking its owner, "ripping apart his hand." The primate, who wore diapers and played with kids, had lived with the family for nine years, having been acquired at three weeks of age. He got out of the house and his owner was trying to catch him with a net. Whether it was the net, the joy of freedom or some other reason, JayJay lost it and clamped down on his owner's buttocks, thigh and hand, respectively, refusing to let go. A friend had a gun handy (no comment) and shot the monkey at the owner’s behest. The bite on the hand (in particular) was severe and deep, damaging tendons and a nerve, requiring surgical repair. This is another example of the "loving" exotic family pet going berserk for some unknown reason. The macaque often played with kids and the owners took him out in public (e.g. dressing him up and taking him trick-or-treating at Halloween). If we can say anything good about this, it’s good that it was the adult owner who was attacked and not a child. Fortunately, unlike a large percentage of captive macaques, JayJay wasn’t a carrier of herpes B virus, a virus that can rarely cause fatal infections in people. A good closing statement was made by Lion Country Safari wildlife director "Anybody that keeps a monkey is going to get bit... I haven't heard of a monkey that wouldn't bite someone."
- A zookeeper in Berlin, Germany, was killed by a Siberian tiger that had escaped its enclosure. While not a pet, it’s another example of a fatal attack by a captive large cat. As with venomous snakes, there is a remarkably large number of these animals that are privately owned, and attacks certainly happen. Usually, the lucky survivors say it was a "freak incident" and totally unexpected because the animal was like a pet cat. The unlucky ones can’t talk, but often the same story comes from friends and family… the animal was this apparently loving, docile large cat that for some reason attacked. You can never be confident that these animals are safe, because fatal injuries can occur not just with attacks, but with playful behaviour given their size and strength.
- In a related theme, a cougar was shot and killed in Muskoka Lakes, Ontario, after attacking a pet dog. The fact that the cougar had been declawed was a pretty good indication that it was an escaped pet. The owner of Guha's Tiger and Lion Farm, an "exotic animal menagerie" located down the road from where the cougar was shot, says he is not missing any of his cougars, which would "never want to escape" (except, I guess, for the jaguar that was shot by police after escaping in 2008). Since there's no regulation of exotic animals in the province, no one will know for sure from where the cougar came, how many cougars are present in Ontario and how they are being managed. Hopefully Mr. Guha has a containment plan for his other cougars, lions and jaguar that goes beyond assuming they'd never want to leave. If I was a neighbour, I wouldn't be too confident, however, when he says things like "If I leave the gate open for some reason — like I unlock it, then the phone rings so I pick up the phone — if they do get out they’ll go sit by (my front door) and wait for me."
The US Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health has launched a website entitled Veterinary Safety and Health. It's designed to provide occupational health and safety (including infection control) information for people in the veterinary field, as well as people in zoos, animal shelters, kennels and other animal-contact situations. It's largely designed to be a central resource to link to available information (which makes more sense than trying to re-invent the wheel), combining a range of topics from general occupational safety to veterinary-specific infection control, hospital design and related topics. Worms & Germs Blog is included as one of the links in their resources list under Hazard Prevention and Infection Control.
After being a relatively rare problem in most regions over the past few years, West Nile virus (WNV) case numbers have boomed lately, with large outbreaks in some US states.
Forty-nine (49) confirmed or probable human cases have been reported in Ontario, the largest number in a decade. Considering we're just heading into the typical peak WNV season, it's quite concerning as the worst may be yet to come. At this time last year, there were only 24 reported cases.
Human cases have been reported in at least four other provinces: Alberta, Manitoba, Saskatchewan and Quebec.
Two equine cases of WNV have been reported, one in Saskatchewan and one in Quebec. It's hard to have a lot of confidence in this number because of the poor surveillance and reporting for this disease in animals in Canada, given that the CFIA has largely washed their hands of dealing with it. Infection with West Nile virus has been pretty much a non-entity in most regions over the past few years, at least in terms of diagnosed cases, and it remains to be seen whether equine cases will mirror the spike in human cases this year. Typically the trends are similar each year, so the next few weeks will tell us a lot.
The US is in the midst of its largest WNV outbreak ever. At least 1118 human cases have been reported so far in at least 37 states, with at least 41 deaths. Typically less than 300 cases are reported by this time of year. Texas has experienced a huge outbreak, accounting for about half of the US cases.
There hasn't (apparently) been a surge in equine cases, with less than 100 cases of WNV reported in horses as of August 18. Whether that's because of infrequent testing, biological or geographic factors resulting in less equine exposure or vaccination of horses (remember that there is no WNV vaccine for people) isn't clear.
Concern is being raised about risks to pets, but the true risk is very limited. While WNV infections have been reported in dogs and cats, these are extremely rare and dogs and cats are failry resistant to the virus.
Often, when a new infectious disease emerges, the first year or two are the boom years, after which things settle down. That was the pattern with WNV in most areas; however, this year in on track to meet or surpass the numbers from those early years.
Why is this happening? No one knows for sure. Changing weather patterns, by chance or through the larger spectre of global warming, are probably playing a major role. Warmer temperatures let mosquitoes mature faster and allow the virus to grow quicker in the mosquitoes. Milder winters help mosquitoes survive. Any factor that fosters more mosquito numbers and growth, particularly the subset of mosquitoes that bites both birds (the reservoir of the virus) and people, can increase the risk of human and animal exposure. Changes in rainfall, wetland management, climate and human proximity to mosquito breeding sites can all play a role.
'Tis the season for ringworm, I guess.
The Guelph Humane Society has closed to visitors, and adoptions have been suspended in response to concerns about the potential for a ringworm outbreak. Implementing a proactive response, all animals are being tested for ringworm and all cats are being treated. While the scope of the problem isn't yet clear (and hopefully it's minimal), this type of response is the optimal approach because waiting to "see what happens" and waiting for culture results (which can take a long time) before deciding to take aggressive measures results is a much greater chance of things getting out of hand.
In an outbreak like this, the first week or so is critical. Introduction of an animal that's carrying ringworm is hard to prevent, as is limited transmission within a shelter (even with good routine infection control practices) from that first case. That's the non-preventable component of shelter diseases. However, it's the 2nd generation of transmission (transmission of ringworm from that initial animal or group of animals to the broader population) that leads to things getting out of control. That's the preventable fraction of infections, on which we can have the biggest impact. It's during this early phase where intervention is critical It's always better to have an overly aggressive response and simply tone it down after a few days, than to have an inadequate response that lets things spiral out of control.
More information about ringworm can be found on the Worms & Germs Resources - Pets page.
A few years ago, I looked out my kitchen window one holiday morning and saw a newborn foal running outside of a fence line. The foal had been born to my neighbours' mare, a maiden mare, and they were out of town. The mare had rejected the foal and wasn't interested in any of my attempts to get them back together. She also had little colostrum (the first, antibody-rich milk that foals need to drink early in life to survive). To make a long story short, I ended up doing a field transfusion, collecting blood from another horse on the farm to give to the foal, to provide it with those much-needed antibodies. The donor horse was healthy and I didn't know of any disease issues in the area, so I was pretty confident that there wasn't a significant risk of disease transmission, but you never know. Ideally, equine blood donors are screened for infectious diseases, particularly equine infectious anemia (EIA), since EIA is a rare but nasty disease that can be spread by blood.
When I started to read a report the other day about a transfusion-associated EIA infection in a German foal, my first thoughts were "that's bad," followed by my ever-optimistic side thinking "well, maybe it was an emergency transfusion and it was a bad but unavoidable consequence" or "maybe it the donor was properly screened but was infected with the EIA virus after it's last test" (the latter situation is an ever-present risk when you are screening donors in advance (days, weeks or months) of collecting the blood for transfusion, since test results only tell you what their status was at the time of testing).
Unfortunately, it didn't take long to see that this wasn't an unfortunate or relatively unavoidable infection. Rather, I can only interpret this as stunning negligence.
Here's the story
- On August 2, EIA was confirmed in a 3-month-old foal in North Rhine Westphalia. When the foal was two days old, it had a septic joint (and probably an overall deficiency in antibodies) and was treated with a plasma transfusion, which is a pretty standard procedure in such a case.
- EIA antibodies were then detected in the donor.
- Since 2009, 20 other horses had received plasma from this horse. Four have been confirmed as infected, and horses that live with these infected animals have been quarantined until test results are back. Positive horses are typically euthanized because they pose a lifelong risk of transmission of the virus to other horses. The four positive horses in this case have been euthanized (and presumably the foal as well).
So, this wasn't some random emergency field transfusion, or a donor that got infected after testing. It appears that this donor has been used for years with no testing, despite the fact that it's well known that EIA transmission is a risk from blood transfusions and the virus is present (albeit rare) in Germany. While there are no standards of care for equine blood transfusions (as opposed to dogs), EIA testing is a standard recommendation in anything I've seen written about equine blood donor programs (click here for one example). Sometimes you get put into situations where testing can't be done in time for logistical reasons, but I can't see how anyone would not test horses that are to be used for a formal donation program or repeated transfusions. Failure to do low cost and easy EIA screening of that donor horse has resulted in the deaths of multiple horses, with the potential for even broader secondary transmission of this virus to additional animals.
The scope of the outbreak isn't really clear from press reports, but "a couple" of other animals now have signs of the skin disease. Investigation of the timing and likely sources of exposure of new cases is crucial. They may just be animals that were infected early, before the problem was recognized (the best case scenario) but investigating these "new" cases is very important because if these animals were exposed after the outbreak was identified, then there are problems with containment.
Shelter personnel have declared that they aren't planning on euthanizing more animals, but the shelter remains closed for adoptions. Stray animals will continue to be accepted. This creates a tricky situation where new animals (e.g. fuel for the fire, if things aren't under control) come in and can actually propagate the outbreak. It also creates overcrowding issues since the shelter was probably pretty full to start with, and continuing admissions with no adoptions can't be maintained for long. The shelter is looking at renting units in which to put animals - this is a relatively common approach for creating more contained spaces, and one that can be useful if good infection control practices are in place (although I've seen too many outbreaks where the offending pathogen quickly makes its way into the new units). Clear policies, sound training, careful supervision, exquisite planning and good communication are critical for making a situation like that work.
While the shelter has gone from an unrealistically optimistic time frame to a warning about long-term efforts, as with most things in life, the middle ground is usually the most accurate. Ringworm outbreaks can't be declared over in a few days (it's possible to contain it in a short period of time, but not declare an outbreak over). A few days isn't even enough time to get culture results back to figure out exactly what's happening. Testing, isolation, cohorting, mass treatment, evaluation of training, evaluation of infection control practices, and similar measures are needed, but if done right, an outbreak can be contained in a reasonably short period of time. Given the need to repeatedly treat all animals (affected animals are being bathed every three days with a medicated solution) and the time lag for ringworm culture, it's going to take at least a few weeks, but let's hope this outbreak ultimately gets measured in weeks rather than months.
This week an article on TheHorse.com discussed the current situation in the western provinces of Canada with regard to equine infectious anemia (EIA). The prairies are seeing the highest number of EIA cases in years, with more than 70 horses affected on 22 different properties.
Also commonly called "swamp fever," EIA is caused by a retrovirus, similar to the human HIV. There is currently no vaccine against virus, and once infected a horse carries the virus for the rest of its life. Although EIA can cause severe clinical signs (including high fever, weakness, swelling of the lower limbs and along the ventral abdomen, and even sudden death) most horses that are diagnosed are not showing any signs of illness at the time, or may show milder, non-specific signs such as exercise intolerance and intermittent fever. Affected horse of course also have varying degrees of anemia as the name suggests. Episodes of more severe signs can occur even years after the initial infection, and during these episodes an infected animal poses the greatest threat to other horses because the viral load in the bloodstream is very high. The virus cannot be transmitted directly between horses though - it is transmitted by blood, typically via blood-sucking insects like like deer flies, horse flies and stable flies (hence the association of the disease with swamps) or by reuse of needles for injections. Fortunately EIA does not affect humans or any other animal species. It has also not been shown to be transmitted by mosquitoes.
Because infection is life-long, in order to control the disease the only options for positive horses are euthanasia or life-long quarantine in a building with rigorous insect control to prevent spread.
The question is, why the sudden spike in the number of cases out west? There are a few possibilities:
- Possibility #1: There's been one, or a few, small local outbreaks that were initially caused by a very small number of positive horses that likely brought the virus back with them from somewhere to which they had traveled. Hopefully this is the case, and testing has identified all the horses that were subsequently infected so that the virus won't spread further. EIA testing is required prior to travel to many places and prior to participating in many competitions or shows. Regular testing of animals that travel frequently helps to identify infected animals more quickly.
- Possibility #2: For whatever reason, there are a bunch of horses being tested this year that have not been tested in the past, and they're coming up positive. This would be much more concerning, because there's no way to tell how long a horse has been infected if it has not been tested in the past. The longer an infected horse is around outside of a fly-proof quarantine, the greater the chance that an insect (or a needle) will transmit the virus to another horse.
- Possibility #3: There are number of infected horses across the prairies that have not been tested, and the virus has been slowly spreading from these index cases and has finally reached part of the horse population that does get tested regularly. This would be the worst case, as it would mean that there's a reservoir of infected horses that is still not being identified, and could continue to perpetuate the infection.
In the end, only time will tell which of these scenarios (or a combination of them) is playing out in western Canada. Although a relatively low population density (of horses as well as people) in provinces like Saskatchewan helps to decrease the transmission pressure (simply by making it harder for an insect carrying the virus in its mouth parts from one horse to find another horse to bite), gatherings of horses for shows, trail rides and the like (particularly when EIA testing is not required) still create prime opportunities for transmission of the virus.
There are also a few things you can do to help decrease the chances of your horse contracting EIA:
- Protect your horse from biting insects that transmit EIA (which will simultaneously help protect your horse from insects like mosquitoes that can transmit other viruses). Use fly repellants, fly sheets, and avoid turnout during times of peak insect activity (dusk and dawn).
- Never reuse needles, especially between different horses. Also ensure that any other equipment that may be used on your horse (e.g. mouth gags) are always properly cleaned between animals and free from any blood contamination.
- Avoid proximity to horses of unknown EIA status. This can be tough to do if your horse goes to shows where EIA testing is not mandatory, but particularly with the current problems out west (or anywhere else that EIA may be circulating) testing for EIA prior to any event where there will be a gathering of horses should be strongly promoted.
Testing for EIA can be done with a simple blood test. This used to be called a Coggins test, but now a more accurate ELISA-type test is used to test for the disease instead.
Image: Cross-section of the EIA retrovirus (source: USDA Animal and Plant Health Inspection Service)
It might just be my perception, but it seems like there are a lot more reports of nasty dog bite infections in the news lately, particularly infections caused by the bacterium Capnocytophaga canimorsus. I don't know whether that's because they are becoming more common, more commonly diagnosed (since the bug is hard to identify), more commonly reported in the press or a combination of all three (or whether my perception is simply incorrect).
The latest report is from Omaha, Nebraska, where a 50-year-old man died four days after suffering a minor dog bite on the cheek. The cause of infection wasn't reported, but the article says that he was unable to fight the infection because he didn't have a spleen. For me, minor bite + fatal infection + no spleen = Capnocytophaga infection until proven otherwise, since this is a textbook description of such an infection, and Capnocytophaga can be found in the mouth of virtually every dog.
This follows the high-profile case of a cancer survivor who lost her hands and feet from Capnocytophaga infection complications and a UK inquest into the death of a man caused by infection with this bacterium, among other cases.
Here are the simple take home messages:
- Avoid bites and any interactions whereby dog saliva may come in contact with non-intact skin.
- Know if you are at high-risk for an infection caused by a bug like Capnocytophaga. This bacterium typically doesn't cause disease in healthy individuals but can produce rapidly fatal disease in certain people.
- Realize that minor bites can cause major problems (even if you are otherwise healthy).
- Use good first aid practices if you or someone you're with is bitten, including careful washing of the wound and seeking medical care if you are at increased risk of infection, or if the bite is over the hands, feet, face, joints or other sensitive areas.
The facility was closed to the public on August 4th because three cats and one dog were showing unspecified signs of ringworm.
Samples were collected for testing, but they decided to euthanize the 4 animals.
"You’re kind of under the gun to decide what you want to do,” said their operations manager. I can certainly empathize. It's not easy to deal with an outbreak. However, from my standpoint, if you feel like you're under the gun in that kind of situation, you're likely to make (or to have already made) mistakes. If you're managing the situation well, getting advice and following standard practices, you may be stressed, exhausted, humbled and concerned, but you shouldn't feel "under the gun." Maybe euthanasia was warranted here, but with a small number of infected animals, the ability to potentially isolate and treat them, and lots of information about how to manage ringworm to avoid further spread, it's important to avoid a panic response that leads to premature euthanasia decisions.
The three cats that were euthanized apparently did not have ringworm, but the shelter is "certain" (not sure how) that the dog had ringworm. Sudden onset of skin lesions in dogs and cats at the same time is certainly suggestive of ringworm, and if the dog was truly infected, it's hard to believe the cats were not (especially since cats are most often affected in ringworm outbreaks compared to dogs). So I wouldn't be too quick to rule out ringworm in the cats. Ringworm culture can take a couple of weeks, so it's not clear to me whether this interpretation is based on culture results or not.
"With the results being better than expected, the humane society will not have to move larger numbers of possibly infected animals to a different facility — the usual procedure in an outbreak." While I can't say too much from a distance, I can say that moving animals to another facility is certainly not a typical outbreak response measure. It's an effective outbreak propagation measure, since it can easily disseminate ringworm to other places, so it's good to hear that they are not planning on moving animals. It's much better to manage things well at one site than to have to manage things at multiple sites.
They state that "the situation now appears to be under control." Hopefully that's true, but it's way too early to say. You can't declare an outbreak over a few days after you declare that it started. There hasn't even been enough time for any animal or environmental ringworm culture results to come back. Closing, testing, treating all exposed animals and thorough cleaning and disinfecting of the environment can be a great start, but trying to say "we won" too early often leads to inadequate response and continuation of the outbreak.
"We’re keeping our fingers crossed and hoping that everything comes back negative so we can be open for business sometime next week" Again, I'm not involved and I'm working with sparse information, but this seems to be way too early to reopen the shelter. You need to make sure things are really under control before you get out of "outbreak mode" and before you can be "open for business" again. That's especially true with a disease like ringworm that is highly transmissible and can be spread to people. Too often, a small outbreak is identified and declared over prematurely, only to be followed by a big mess in short order. Let's hope that's not the case here.
Image: Photo of a dermatophyte-positive culture specimen, which can take two weeks or longer to grow.
If I was reincarnated as a mosquito, I'd want to live where I do now (convenient, eh?). I live in the country surrounded by areas of "protected wetland," which, in many cases, is a fancy word for swamp. I try to avoid mosquitoes, but getting bitten is a regular (daily) event. As I was getting swarmed last night, I was thinking that the mosquito-borne disease I'm really concerned about is Eastern equine encephalitis (EEE). While quite rare in Ontario, with only a handful or no cases in horses every year, it's a worry because it's almost always fatal. It also affects people, not via transmission from horses but from being bitten by mosquitoes that pick up the virus from birds. It's very rare in people, but it's highly fatal.
This is the time of year that we start seeing mosquito-borne infections in Ontario, and a Disease Alert from the province re-inforces concerns about EEE. The alert was issued in response to a case of EEE in a horse in New York state, not far from the Canadian border. The horse, from the Ogdensburg, NY area, showed signs of illness on July 23 and died the next day (a pretty typical progression for this disease). Since mosquitoes don't respect borders, cases in this neighbouring region suggest that infected mosquitoes might also be active in Ontario.
EEE isn't the only mosquito-borne virus that we worry about - West Nile virus being the other main issue around here - so mosquito control and avoidance are important. While you can never guarantee that you or your animal will not encounter a mosquito, various things can be done to reduce mosquito numbers (e.g. eliminating sites of standing water (which are mosquito breeding sites) wherever possible... swamps being a logical exception) and to reduce the risk of being bitten (e.g. avoiding high risk areas and times, long clothing, mosquito repellants). Vaccines are available for EEE and West Nile virus in horses (but not people), and the risk of these diseases should be considered when designing a horse's vaccination program.
A short distance down the road from here, the Kitchener-Waterloo Humane Society has been quarantined because of an apparent ringworm outbreak. There's no information on the facility's website and information in the press has been pretty vague (both concerning aspects), but it sounds like a ringworm outbreak. Adoptions have been ceased and the Humane Society will apparently "reassess its safety protocols by the end of the week." The outbreak appears to have been going on since at least last week, so hopefully they're getting on this and have a strong outbreak investigation and control plan in place.
I haven't been involved in this outbreak so I know nothing more than what is in the press, but ringworm can be a big problem in shelters. It's a controllable disease, but the situation can get completely screwed up with a poor outbreak response. It's also sometimes an overblown problem (or not a true problem at all) in some situations, so it's critical that the outbreak is properly investigated and managed. That's not always the case, and the consequences can be serious.
There are a lot of factors that go into good outbreak management that are hopefully being done at the KW Humane Society. These include:
- Good communication both internally and externally.
- Sound containment practices.
- Getting good advice.
- Actually listening to the good advice (and not bad advice).
- Taking the time to do it right.
- Ensuring one is acting on correct information.
- Spending money where it needs to be spent, be it testing, treatment, personnel or other factors. Trying to save money during an outbreak response often ends up costing much more in the end.
The independent report of the 2010 ringworm debacle at the Newmarket OSPCA should be important reading for any shelter trying to figure out what to do, and what not to do.
Rabies is most commonly reported in dogs, skunks, raccoons, bats and a few other species. However, any mammal is susceptible, and sometimes unusual cases are identified.
1. In a serious take on Monty Python's "killer rabbit," a rabid bunny has caused a lot of problems in Chom Thong, Thailand.
The pet rabbit, Poko, had been purchased last year and starting biting the feet of people in the family on June 10. The rabbit was eventually put in a kennel and died July 28. The other rabbit in the house died the next day (no word on why). The time frame is a bit strange, since if the rabbit was biting because of rabies, it should have died a lot quicker. Once an animal is showing signs of rabies, death occurs quite quickly (usually within 10 days), not over a period of 7 or 8 weeks. So, most likely the rabbit wasn't biting because of rabies, at least at the start.
In response to the diagnosis, authorities have launched an investigation and 120 health officials are fanning out in the area to look for other rabid animals, since where there is one, the are others. Dogs and cats within 5 km of the rabbit's home are being vaccinated against rabies. Family members are being given post-exposure prophylaxis. The father has expressed concern that the treatment was too late since they were bitten several days before, but it's not really much of a risk. Rabies typically has a long incubation period, especially with bites to lower extremities, and starting treatment a few days (or even weeks, in some situations) after exposure can still be effective (albeit the sooner the better). The key is for treatment to be started before any signs of rabies develop - after that happens there's very little that can be done.
The source of rabies isn't clear and I haven't seen any speculation. If the rabbit was caged, then there aren't too many possible sources, with bats probably being the most likely.
2. Swimmers beware... it's not just rabid otters you need to worry about.
A man swimming in eastern Pennsylvania was bitten by a beaver that was subsequently identified as rabid. The beaver apparently attacked a canoeist earlier that day, before encountering the swimmer, a Boy Scout leader. The man suffered 15 lacerations from the attack, and the beaver remained firmly attached to the man's arm as he was helped to shore. The stubborn critter wouldn't let go until the resourceful (and brave) Scouts got it off by hitting it with "anything they could find around them, sticks, rocks..." The beaver was killed and confirmed as rabid.
It's another reminder that any bite from a mammal should be considered a possible rabies exposure. It's also a reminder to avoid contact with wildlife, although that can be easier said than done when a rabid animal is involved.
While I'm certain I'll face more wrath from the keep-reptiles-in-schools group that is currently bashing me on the internet (there's even a Facebook page... at least I'm making an impact!), this brings up a few serious issues. One is the whole idea of putting a python around the neck of a young child. I won't go there, and in reality the risk of injury is very low. The main issue is, obviously, Salmonella exposure, because of the high rate of Salmonella shedding in reptiles and the high susceptibility of young kids to salmonellosis. A recent paper in Zoonoses and Public Health (Hydeskov et al. 2012) provides more evidence that the concerns about Salmonella exposure in such situations are valid.
- This study involved the reptile collection at the Copenhagen Zoo. There, the reptile collection consists of two groups: the main group is comprised of animals in the breeding centre, quarantine station and the primary zoo exhibit; the other group is a smaller collection that's used for education and hands-on teaching. The latter group has direct contact with many people, including kids.
- Salmonella was isolated from 35% of reptiles overall, with the highest prevalence in snakes (62%).
- Reptiles from the education group had a significantly higher prevalence than the other reptiles; 64% vs 23%.
- While these numbers are high, they are presumably an underestimation, since other studies have shown that you will miss a reasonable percentage of positive animals if you only test a single sample from each individual. So, it's fair to say that at least 62% of snakes and at least 64% of education-group reptiles were Salmonella positive.
Has the zoo ever been the source of Salmonella in a person? Nothing's been confirmed; however it's important to note that in Denmark, official investigation of salmonellosis cases only occurs as part of an outbreak. Since reptile-associated salmonellosis would most likely occur as sporadic cases, not an outbreak, cases might not be identified and reported.
It's also possible that the zoo hasn't been a source, because of the short-term nature of contact with the reptiles, contact only by older children and their hygiene practices.
At the Copenhagen Zoo, all reptile contact by kids is supervised, and students are required to wash their hands after touching a reptile. That's a great approach (as long as compliance is good), and the risks should be low for a short-term supervised activity such as this. High-risk kids, from an age standpoint, aren't involved since only 7-18 yr old students participate. So, the main group that would be of concern is immunocompromised children, who comprise a small but important subset of participants, and one that may slip by the established control measures since not all immunocompromised kids are readily identifiable. Unless schools know about all high-risk kids (and I'm far from convinced they do) and know that there are things these kids shouldn't do (e.g. have contact with reptiles), there are still some concerns. Those can be lessened further by ensuring that there is good communication between parents and the school, such that schools are really aware of any high-risk kids. That requires adequate knowledge on the part of the parents and the school, good communication in both directions and trust (since private health information is being disclosed). We have a long way to go to get there, and few people seem interested in starting those discussions.
Back to the Guelph paper photo. This wouldn't happen at the Copenhagen Zoo, since they apparently don't let 3-year-olds have contact with reptiles. I wasn't there so I don't know what was done in terms of hygiene, but even if this girl washed her hands after, there would still be a good chance that Salmonella was present on her skin or clothing based on how she handled the animal. This nature centre does some excellent work but I worry about the shows they offer for birthday parties. Their advertisement for this, with the "bring your cake and touch a snake" approach, and the picture of another young child with a snake draped around her raises concerns.
Reptile contact isn't inherently bad. There are just situations when it's high-risk and should be avoided. Beyond that, if it's going to be done, it must be done right. Unfortunately, more often than not, that's not the case.
We’re fully into petting zoo season now, with these types of exhibits appearing at a variety of agricultural fairs and similar events. This also unfortunately means that we’re into petting zoo outbreak season, since there’s always some risk of disease associated with the type of animal contact people have at these displays. There are some basic measures that can and should be taken to reduce the risk of disease transmission, including proper facility design, selection of appropriate animals, good animal health monitoring, sufficient supervision, and above all, providing adequate hand hygiene facilities. Unfortunately, these measures aren’t always implemented - even the really easy ones - be it due to lack of knowledge, lack of interest or downright negligence.
A recent study in Zoonoses and Public Health (Erdozain et al. 2012)(completed under the guidance of Doug Powell and Ben Chapman of BarfBlog fame… or infamy, if you're a particularly slack regulator or politician) evaluated some important public health-related behaviours and factors at petting zoos in Kansas and Missouri in 2010-2011. They found:
- Handwashing stations and signs were present at the exit of 7/13 petting zoos. Yes, it means the majority had them, but it’s a pretty disappointing number. Providing proper hand hygiene stations is easy to do and there’s no excuse for not having them at the exit. The other 6 petting zoos at least had hand hygiene stations within or near animal contact areas, but that’s not ideal. People need to be able to clean their hands on the way out. Doing it in the middle doesn’t help much, and if people have to go out of their way to perform hand hygiene after leaving, it will rarely get done.
- At one event, there was only a sink with no soap, and at another, 2/3 hand sanitizer bottles were empty and there was no area to wash hands. Having hand hygiene facilities is only useful if they are actually appropriately stocked.
- Signs encouraging hand washing were present at the exit of 10/13 petting zoos, but no signs were present at the entrance or entrance to eating areas at any of the venues.
- There were staff monitoring activities at only 6/13 events. At one unsupervised facility, kid goats were able to escape through the fence and were roaming freely.
- When the researchers observed zoo visitors, they noted that only 37% of individuals washed their hands or used a hand sanitizer when leaving. That’s not really surprising, but it’s disappointing nonetheless. People are skipping the best and easiest way to mitigate what is typically the biggest risk factor for pathogen transmission in petting zoos (i.e. contamination of hands ultimately leading to ingestion of pathogens).
- Visitors were almost 5 times as likely to wash their hands when a staff member was present. That’s consistent with a study we published last year and shows the importance of a little encouragement.
- High-risk animals were present in some petting zoos. These included chicks, young ruminants (kid goats) and (a new one for me) a petting zoo that allowed people to enter an area and pet and sit with tortoises.
- People were allowed into animal enclosures in 7 petting zoos, and not surprising, fecal contamination of the ground was common (petting zoo animals not being house trained).
- Various behaviours that might increase the risk of disease transmission were observed, including kids (the human kind, not the goat kind) touching their faces (77% of events), kids eating or drinking in the petting zoo (15% and 38%, respectively), kids eating petting zoo food (7%) and kids sucking on pacifiers (23%). Children were also seen picking up animal feces at one event.
Overall, despite the lessons that should have been learned from various past outbreaks, numerous deficiencies were present, including many that would take little effort to rectify.
The state of petting zoos, at least around here, has certainly improved over the past decade, in part due to more attention from local public health officials, but how do we get more, sustained and widespread improvement?
More strict governmental regulation and enforcement is one way, but that tends to be slow. The more effective approach is probably one that involves the almighty dollar. Most petting zoos are there to make money or bring people to a bigger event that makes money. Like many issues, if consumers start demanding change, change will occur quickly. Maybe that’s easier said than done, but the more pressure that’s put on petting zoo operators and people who run events where petting zoos are present, the more likely it is that change will occur. Visiting a petting zoo can be a great experience, particularly for kids, but we need to make them as safe as possible. Providing hand hygiene stations, some appropriate well-placed signs, having staff supervise, avoiding high-risk animals and logical facility design are easy and inexpensive, and not employing such simple measures is inexcusable.
As with most "pocket pets," guinea pigs don’t get a lot of attention in the scientific literature. As a result, we are limited in what we know about certain diseases in this species, and we tend to rely a lot on personal experience, small case studies and extrapolation from other species. It’s not that these sources of information are bad, they’re just not a replacement for larger, more controlled studies.
A recent study in the journal Mycoses (Kraemer et al. 2012) provides a rather comprehensive overview of ringworm (dermatophytosis) in these little fuzzy critters. The authors surveyed 74 owners of guinea pigs with ringworm and veterinarians. Here are some highlights from the results:
- 97% of ringworm infections were caused by Trichophyton mentagrophytes. Ringworm can be caused by a few different species of fungi, with a different organism, Microsporum canis, being most common in dogs and cats.
- 43% of the time, a new guinea pig was introduced into the household in the weeks preceding the onset of disease, and around one-third of affected guinea pigs had been in the household for less than 3 months. That’s not too surprising, since new animals are often a prime source of infectious diseases. It shows the importance of ensuring that new pets are examined carefully and are healthy before they are brought into the household. It’s certainly no guarantee that there won’t be problems, since healthy-appearing animals can be shedding various infectious agents, but it helps reduce the risk.
- Ringworm lesions were most common around the head. Hair loss was the most common sign, with scaling and crusting also common.
- Signs of ringworm were also present in other guinea pigs in the household in over one-third of cases.
- Various treatments were used and some animals weren’t specifically treated. In fact, 7/8 of the guinea pigs that did not receive specific anti-fungal therapy got better. It's known that ringworm can be self-limiting (meaning the animal will get better on its own over time). However, treatment can speed the process up and decrease the likelihood of transmission to other animals or people.
- In 24% of cases, people in the household also had signs of ringworm, on the head, neck and arms. Children were most commonly involved. That’s not too surprising since kids probably had more contact and closer contact with the animals than their parents.
While not a severe disease, ringworm is a problem because it’s highly transmissible. It can easily and quickly spread between animals, and between animals and people, and elimination of ringworm from a highly contamination household can be a major hassle. Presumably the risk of widespread environmental contamination is less with guinea pigs compared to dogs and cats because of their smaller size and tendency to be kept confined to cages most of the time.
Ringworm should be considered in any guinea pig that develops hair loss or other skin/hair problems. This is particularly true if it’s a new acquisition or if a new guinea pig has been introduced to the household recently.
If ringworm is suspected, a prompt visit to the veterinarian is in order. The guinea pig should be handled sparingly (or ideally, not at all) until the cause of the skin disease is identified. Close attention should be paid to hand hygiene, and even the use of gloves could be considered, although gloves aren’t a cure-all and people sometimes misuse gloves to such an extent that they actually increase the risk of spreading disease.
If a new guinea pig is obtained, it’s ideal to have it examined by a veterinarian before it comes into the household. I’m a realist and realize this is unlikely, but it’s ideal. In lieu of that, it’s important to get a guinea pig from a reputable source, to ensure that other guinea pigs from the same source don’t have skin disease, and to carefully examine the animal for skin lesions before it gets home. It’s also ideal to keep any new guinea pig in its own cage for a couple weeks to act as a quarantine period and allow for identification of any incubating diseases.
If owners of an infected guinea pig develop skin lesions, they should be examined by their physician, and make sure the physician knows they have been in contact with an infected animal.
Vesicular stomatitis (VS) has been reported in a horse in Las Animas County, Colorado. It's the first diagnosed case in the state since 2006, but it's not particularly surprising since this viral disease is periodically identified in horses in various parts of the US, and this case may be associated with northward movement of the virus from the Rio Grande River valley in New Mexico. However, it's noteworthy because VS is a potentially nasty disease and since it's also reportable, diagnosis of a case is accompanied by quarantine and other other control measures.
Vesicular stomatitis typically results in vesicles (small blisters) and ulcers in the mouth, on the tongue and lips, as well as on the udder (udder lesions are more common in cattle compared to other affected species). Lesions around the coronary band of the foot can also develop. Because of these blisters, infected animals may stop eating or drinking, and may be lame. It's a self-limiting disease, meaning it will typically resolve on its own, but animals can develop secondary problems like bacterial infections or severe foot damage, or in some situations the consequences of decreased drinking and eating may be severe, resulting in bigger or longer-term problems. A major concern is that this virus can also infect cattle and produce signs that are similar to the dreaded foot and mouth disease.
The source of infection in this case is not known, but the horse has no history of travel to areas where the disease is active, so insect-borne infection is suspected. That means that the virus must be present in other animals in the region, since blood feeding insects simply spread the virus around, they don't act as reservoirs or amplifiers of the virus. The farm is under quarantine and presumably surveillance is underway to identify other horses that have had contact with the animals on this farm, as well as to monitor for any more cases in the area.
When something like this occurs, travel restrictions for horses (and/or other species) are typically put in place by various governments, ranging from travel bans to requiring animals from areas where the disease is present to be accompanied by a health certificate saying that the horse has no signs of disease and hasn't be on a farm with the disease. Anyone planning travel to, from, or through, involved areas needs to be aware of this and check into transportation rules, including potential import restrictions if they want to enter Canada with a horse.
If you are in an infected region (or nearby), you can do some things to reduce the risk of your horse becoming infected by VS:
- Restrict travel and avoid areas where the disease is active.
- Avoid direct contact between horses as much as possible when visiting farms, shows or other places where horses mix.
- Take basic insect control measures to reduce exposure to biting flies (e.g. black flies).
- Avoid sharing/trading/selling tack and other items that have close contact with your (or any other) horse.
Vesicular stomatitis is zoonotic but it's of limited concern. Human infections are rare and usually just result in flu-like illness.
Sometimes, I get a little concerned when research papers get picked up by the press. It's not necessarily because the research is weak, it's just that results sometimes get overstated or misinterpreted when they work their way outside of scientific forums.
A paper published in the latest edition of the American Journal of Veterinary Research is one of those. The paper (Tsuchiya et al. 2012) describes a study that looked at the impact of interferon-alpha (used to stimulate the immune system) and enrofloxacin (an antibiotic) on body temperature and lung fluid white blood cell counts in 32 horses that were shipped for approximately 26 hours in commercial vans. Horses either received just interferon or interferon and enrofloxacin before being shipped.
- After shipping, 3 antibiotic-treated and 9 untreated horses developed fevers. That's actually not statistically significant, by my calculations, and it's quite strange that the authors didn't do that analysis (and that the reviewers didn't pick that up).
- Two antibiotic-treated and 7 untreated horses were treated with antibiotics after arrival because of concerns about infections. Again, that's not statistically significant and it's surprising (and concerning) no one pointed that out.
- Overall, the average temperature of horses in the treatment group was significantly lower after arrival, but the clinical relevance of that is questionable since it was only a 0.4 C difference. Further, it's hard to say what a temperature immediately after arrival really means, since that's pretty early for a bacterial infection to have developed.
- There were significant differences in tracheobroncial fluid (fluid collected from the airways) between the groups, with lower white blood cell counts in the treated group. That's an interesting finding and is consistent with less inflammation. What that means in terms of disease prevention is harder to say, but it's something worth investigating further.
- There does not appear to have been any difference between the two groups in the ultimate health status of the horses.
This study provides some interesting information to help us think about how, when and why infections and inflammation develop after shipping. Results suggest that antibiotics might be useful in certain situations, but many questions remain. Any antibiotic use runs some risk of complications such as antibiotic-associated diarrhea. It also increases the risk of antibiotic resistance (and ultimately more problems trying to treat disease). We have to remember these issues when considering these results. Further, while it is typically much better to prevent disease than treat it, in situations like this, it's hard to say whether mass prophylactic treatment is actually preferable to early treatment, since horses can be observed closely after arrival and treated when early signs of disease develop. Ultimately, it's still not even clear from these data whether pre-treatment with antibiotics actually does have a positive clinical effect.
It's important to remember what this study tells us, and what it doesn't. Despite what some lay articles that have picked up the story say, it doesn't mean that antibiotics are broadly useful for keeping shipped horses healthy. The authors address this by stating "The use of enrofloxacin raises concerns regarding the emergence of antimicrobial-resistant bacteria, and it is important that antimicrobials such as enrofloxacin are not used inappropriately. The guidelines for enrofloxacin use in the Japan Racing Association’s medical office require that it is only administered as prophylaxis against transportation-associated fever when the duration of transportation is expected to be ≥ 20 hours and the horse has had clinical signs of transportation-associated fever before or is considered to be at risk for developing transportation-associated fever (eg, if the horse has undergone laryngoplasty or has a history of pneumonia)."
Regarding the big picture, however, this should make us think again about how we manage horses. Antibiotics should never be used as a crutch in place of good management. In a situation like this, where 19% of horses treated with interferon and enrofloxacin and 56% of horses treated with interferon alone get sick, something's wrong. Antibiotics may be an easy way to try to reduce the likelihood of disease in some situations, but that doesn't mean it's a good idea. Considering the number of horses that get sick (and die) every year from shipping-associated illness, maybe we need to rethink how they are transported. Is lack of antibiotics the problem, or is it how (and how long) horses are shipped? Maybe long, interrupted trips aren't a good idea, antibiotics or not.
I get a lot of emails about this blog. Some are complementary, some... well... not so much.
When it comes to the latter group, the most common (and often the most grammatically-challenged) group is raw meat feeders. They're a constant source of interesting comments about my intelligence and other aspects of my life. Some actually provide well-written explanations of why they do what they do and I've had some good discussions with a few. Others just like to call me stupid and move on. The guy who provides treatment recommendations for dogs based on fish antibiotics (and his buddies) was another interesting one. The dodgy equine protozoal myelitis clinical trial person (and her friends) was another (she also wrote to my Dean... that's another story). The list goes on.
The latest group has been people upset that I have concerns about reptiles in schools. It seems that a post I wrote a while ago about a school reptile club ended up on a reptile website, whose members are now inundating me with emails. While I appreciate the fact that they are reptile enthusiasts and like their pets, they're missing the big picture.
Yes, reptiles can be good pets, in certain situations. I actually like reptiles. I used to own a few, and the first patient I treated in practice was a reptile.
I've also spoken with people whose children have acquired Salmonella from a reptile. I've read numerous papers about kids that died from Salmonella from a reptile, and I think I've yet to meet an infectious diseases physician who doesn't almost immediately launch into reptile-Salmonella stories when they hear what I do.
The fact is, reptile exposure accounts for a very disproportionate number of Salmonella infections in people, and kids bear the brunt of this. That's why the CDC and various other groups say that reptiles shouldn't be in households with young kids (or the elderly, pregnant women or people with compromised immune systems). The same applies for schools and day cares, where young kids are present, parental knowledge of the exposure is often non-existent, and basic infection control practices are spotty, at best.
No one is saying people shouldn't keep reptiles as pets. However, to me, the evidence is clear that certain people shouldn't have reptiles as pets or be in contact with them. Adults can decide to do things that compromise their health. Adults shouldn't make decisions that compromise the health of their kids or kids for whom they are responsible. Ensuring high-risk children stay away from high-risk animals like reptiles is part of that.
In response to Salmonella outbreaks linked to these critters, their popularity as pets for young kids, and efforts to ban them in some areas, we've developed an info sheet regarding African Dwarf Frogs. As with our other info sheets, it discusses the good and bad points of owning these little guys, things to consider when deciding whether to get one, and measures to reduce the risk of infection.
This info sheet, along with many others, can be found on the Worms & Germs Resources - Pets page in the Information Sheets for Pet Owners section.
The old saying is "when you hear hoof-steps, think horses, not zebras." In a medical context, it means common things occur commonly, so don't start off thinking about wild and bizarre conditions before you've ruled out the usual suspects. Along that line, when I hear "rabies," I think "bats, raccoons, dogs, cats, foxes..." I don't think about... zebras.
Considering there aren't that many zebras in Ontario, and even in places where there are zebras, most people don't have a lot of contact with them, it makes sense that zebras don't typically make the rabies suspect list. But that doesn't mean zebras can't get rabies.
A Letter in Emerging Infectious Diseases (Lankau et al, 2012) describes one such unusual scenario. In January of 2011, an orphaned zebra foal was taken in by a safari lodge (that's probably not too unusual of an occurrence), and not surprisingly, tourists were allowed to handle and feed the foal. Unfortunately, the foal was bitten by a dog at the end of July. The dog was suspected of being rabid but it doesn't seem like any changes were made to how the baby zebra was handed. Unfortunately, the foal died at the end of August and rabies was confirmed. Lodge staff tried to contact people who had visited during the July-August time period, mainly through emails to travel-booking agents who (it was hoped) forwarded the information to travelers.
Several US travelers contacted CDC after getting the email and their risk of rabies exposure was investigated.
- CDC obtained names of 243 travelers who were at the lodge, 136 of whom were from the US.
- They worked with the assumption that the outside window for rabies virus shedding by the zebra was a 14 day period leading up to its death. Seventy-seven (57%) of the US visitors had been there during that period.
- Twenty-eight of those visitors had already started post-exposure treatment for rabies. None of those individuals had high-risk exposures, 2 had moderate-risk exposure while the rest had low or no-risk exposures, so treatment would not have been recommended for most of them. That's probably because the information went from the lodge to travel agents to travelers, and then to the peoples' general physicians (who are generally less well versed in rabies exposure issues) rather than through public health.
- The cost of rabies post-exposure treatment is at least $4000/person in the US (although I know of cases where the cost was much higher), so at least $100 000 was wasted, in addition to stress and other factors.
Some take home messages
- People need to think about animal contacts when on vacation. Travelers that go to rabies-endemic areas need to pay particular attention to avoid high-risk contact with animals.
- Facilities that allow animal contact need to protect the public. Rabies vaccination of this foal might have prevented its infection and the subsequent human exposures.
- If an animal has been attacked by a rabid animal, don't let people come into contact with it!
- Rabies exposure is a medical urgency, not an emergency. There's time to make sure things get done right, and public health personnel should be involved in discussions of exposure and treatment.
The outbreak stretched over a long period of time, from 2007-2009, and involved a strain of Salmonella called Salmonella Java. During the course of the investigation, 75 people with S. Java infection were identified, although there were probably many more infected since diagnosed cases are usually the minority of the true total.
Individuals affected ranged in age from 1 month to 60 years, but the median age was only 2 years, which means the majority were very young children. The investigation started to focus on playgrounds and ultimately 207 sand samples were collected from 39 locations. Thirty-five isolates of S. Java were found, all from 6 playgrounds. These playgrounds had all received sand from the same depot over the preceding year, but Salmonella wasn't found in samples from the depot.
To try to find a source, they started testing critters living in the area of parks, and found S. Java in 34 of 261 animals, mainly from long-nosed bandicoots (a marsupial indigenous to Australia).
It's possible that this Salmonella strain is widely present in bandicoots (and other critters) in the area. I don't know their defecation habits, but if they have a preference for pooping in sandboxes (like cats do), they could be contaminating play areas. The other possibility is that the sand was contaminated from some other source and the bandicoots were infected from the sand just like the people. There's not really any easy way to figure that out.
Sandboxes have been associated with various disease outbreaks, but the overall risk is low and it's certainly not a reason to keep kids away from them. Some things that can be done to reduce the risk of potential disease transmission from things in the sand include:
- Supervising kids to prevent them from sticking things in their mouths.
- Making sure they don't eat or drink in the sandbox/playground.
- Making sure they wash their hands after playing in the sand.
- Covering the sandbox whenever it's feasible (not always an option but good if it can be done) to help prevent animals from defecating in the sand.
More information about sandboxes and potential disease risks can be found on the Worms & Germs Resources - Pets page.
Image: Long-nosed bandicoot from Eastern Australia (Perameles nasuta)(click image for source)
Let me say it again... yes, dogs can get salmonellosis.
...and in French, oui, les chiens peuvent devenir malades de salmonellose (hope that's close)
...and in Swahili, ndiyo, mbwa anaweza kuwa na wagonjwa salmonellosis (thank Google Translate for that one).
What prompted my recurrent 'yes dogs can get Salmonella rant'? Another fluff piece on feeding dogs raw meat diets, this time in the Globe and Mail (a national paper in Canada).
The "dogs can get Salmonella" rant doesn't actually stem from the newspaper, since the article didn't even bother to get into potential infectious disease or nutritional deficiency concerns with these diets (in-depth reporting it was not). Rather, the rant is in response to comments on the paper's website that include the typical garbage that dogs are not susceptible to Salmonella because of their short and acidic intestinal tract. It's a fallacy that's widely distributed on the internet on raw pet food sites, and it's wrong (although ironically enough, many of these same sites also talk about how dogs get sick from Salmonella from commercial foods).
To set the record straight:
- Dogs can get Salmonella.
- Most often they don't get very sick, but sometimes they die.
- Ingesting Salmonella from food or other environmental exposures is the source.
- The more Salmonella a dog eats, the greater the risk of disease.
- Raw meat is often contaminated with Salmonella.
Now that I've gotten that off my chest, I'll get back to the article. It's written by someone who feeds her dog raw meat. I have no major problems with that for the average dog and average person. It increases the risk of salmonellosis in the dog and in the family (and potentially anyone or anything in contact with the dog or its poop), but the risk of infection for your average, healthy dog and person is relatively low. It's a bigger issue when there are high risk people or animals in the house, and human and pet infections from feeding raw meat certainly do occur.
I'd rather people not feed raw (or at least make sure they feed high pressure pasteurized raw meat) but I'm a realist and I realize some people are going to do it anyway. I therefore focus on trying to educate people about situations when they really shouldn't feed raw meat (e.g. high risk dog or person in the household, young growing animals) and what to do to decrease the risk of transmission of Salmonella. More information of this kind is available on the info sheet that can be found on the Worms & Germs Resources - Pets page).
Anyway, back to the article (I really mean it this time). The article includes some interesting information, particularly the very high cost of feeding a raw diet compared to commercial dry or canned foods. However, it also contains some of the same drivel that's found in most of these articles. For example:
"'Dogs don’t have microwaves or grocery stores in the wild,' she says with a laugh, adding that she believes a dog that eats raw will lead a longer, healthier life than one fed traditional dog food."
- They also don't necessarily live long, happy and healthy lives in the wild. Today's domestic dog is long removed from the mystical wild dog. My dog Meg wouldn't make it very far in the wild, unless there are dog food trees somewhere that I don't know about.
"'On a kibble diet, her dogs were 'overweight, with no energy - scratching all the time from all the allergies,' she says. 'These were our fat, miserable, lethargic dogs.'"
- Less food, more exercise and good veterinary care could probably have taken care of that too.
As I said above, people are free to make their own choices, but they should get informed, and they need to go beyond raw food company websites and support groups. They need to think about potential benefits, potential risks, cost, hassle and other factors to determine if it's right for them and their dog. Getting real information and critically assessing the information that's out there are critical steps.
Q-fever, a serious disease caused by the bacterium Coxiella burnetii, is an important concern at petting zoos because small ruminants (sheep and goats) are commonly present at these events and they are the major source of this pathogen. The risk is greatest around adult animal at the time of birthing, and around the new lambs and kids (baby goats), because this is when large numbers of highly infectious Coxiella can be shed. That’s one of the reasons why pregnant small ruminants shouldn’t be part of any petting zoo, but unfortunately this particular recommendation is widely disregarded.
Other than petting zoos, the general public can also have contact with small ruminants through various other routes. An outbreak of Q-fever in the Netherlands (a country with serious Q-fever problems) was reported in association with one of these atypical events, namely "lamb viewing days" on a farm (Whelan et al, Epi Infect 2012).
This farm was open to the public every year during lambing season, and attracted about 12000 visitors from the area annually. Visitors could watch lambs being born (if the timing was right) and interact with young lambs. After finding a cluster of Q-fever cases in the region, an investigation ensued, which compared people who were diagnosed with Q-fever in the region to a group of people without Q-fever. Here are some of the highlights:
- 21% of people with Q-fever reported visiting the farm compared to just 1% of controls.
- When various other factors were controlled in the analysis, having visited the farm meant someone was 43.3 times as likely to have Q-fever compared to someone who didn’t visit the farm.
- Coxiella burnetii was identified in numerous sheep, as well as from 7 of 8 air samples collected on the farm. (Coxiella is a very small, hardy organism that can resist drying, and it can therefore often be found in the dust in the air in areas that have a lot of environmental contamination, like pens where goats and sheep give birth.)
- Specific contacts (e.g. holding a lamb, witnessing a birth) were not identified as risk factors, but the small sample size of people that reported what types of contact they had may have limited the ability to detect a difference.
Visiting farms and having contact with farm animals shouldn’t necessarily be considered a high-risk behaviour. In fact, in some ways it’s a good thing. Greater contact between people and animals and a better understanding of farm animals can be very beneficial. However, we’ve known for a long time that some situations pose an increased and unnecessarily high risk. People organizing farm encounters or petting zoos need to take some basic precautions to reduce the risk to visitors. These are pretty simple and can be done without significantly affecting the visitors' experience. Visitors also need to take some responsibility themselves and follow recommendations, like practicing good hand hygiene and keeping food and drink out of animal areas (just to name a couple). Additionally, the more visitors know about risks and preventive measures, the more they can pressure facilities into doing things right. Public health personnel can work hard to try to improve petting zoos and other events, but nothing will change things quicker than an informed public withholding their money from places that put them at unnecessary risk.
I've had a run on questions about survival of rabies virus outside the body. The topic comes up periodically with respect to touching roadkill or veterinary clinic personnel working with animals that have been attacked by an unknown animal. The case of three people who developed rabies after taking care of a sheep that had been attacked by a rabid animal, probably through contact with saliva from the rabid animal on the sheep's coat coming into contact with broken skin on their hands, shows the potential risk. An important part of assessing the risk is understanding how long the virus lives outside the body.
Some viruses are very hardy and can live for weeks or even years outside the body. Parvovirus and norovirus are classic examples of this type. Some viruses, like HIV, die very quickly in the environment. Part of this relates to whether they are "enveloped" or "non-enveloped" viruses. Enveloped viruses have a coating that is susceptible to damage from environmental effects, disinfectants and other challenges. Damaging this coating kills the virus. Non-enveloped viruses don't have that susceptible coating and that is in part why they are so much hardier.
Fortunately, rabies is an enveloped virus, and it doesn't like being outside of a mammal's body. Data on rabies virus survival are pretty limited, since it's not an easy thing to assess. To look at rabies virus survival, you have to grow the virus, expose it to different environmental conditions, then see if it's still able to infect a mammal or a tissue culture. We can do this easily with bacteria, but growing viruses is more work, especially a dangerous virus such as rabies virus.
I can only find one study that has looked at rabies virus survival (and I can only read the abstract since the rest of the paper is in Czech). The study (Matouch et al, Vet Med (Praha) 1987) involved testing of rabies virus from the salivary gland of a naturally infected fox. They exposed the virus to different conditions and used two methods to look at the infectivity of the virus.
- When the virus was spread in a thin layer onto surfaces like glass, metal or leaves, the longest survival was 144 hours at 5 degrees C (that's ~ 41F).
- At 20C (68F), the virus was infective for 24h on glass and leaves and 48h on metal.
- At 30C (86F), the virus didn't last long, being inactivated within 1.5h with exposure to sunlight and 20h without sunlight.
So, rabies virus can survive for a while outside the body. Temperature, humidity, sunlight exposure and surface type all probably play important roles, but in any particular situation you can never make a very accurate prediction of the virus's survival beyond "it will survive for a while, but not very long."
From a practical standpoint, it just reinforces some common themes:
- People should avoid contact with dead or injured animals.
- Veterinary personnel or pet owners dealing with a pet that has been attacked by another animal should wear gloves, wash their hands and take particular care if they have damaged skin.
- People who are at higher than normal risk of being exposed to potentially rabies-contaminated surfaces should be vaccinated against rabies.
Image: Schematic diagram of a rabies virus showing the outer viral envelope (source: CDC Public Health Image Library)
I love my cats. But sometimes when Bonnie and Clyde are living up to their names, puking up hair balls twice a day, peeing on the guest bed (yes, contrary to popular belief even vets can't stop their own cats from doing this sometimes), caterwauling at 3 AM, or begging for food all afternoon, they do make me c-r-a-z-y crazy - but they're not making me suicidal.
In yet another example of how the media will present study results in the manner that will sell the most newspapers or magazines, rather than the way that helps people interpret the results in a logical manner, comes an article entitled "Is Your Cat Hosting a Human Suicide Parasite?" The article talks about a study recently published in the Archives of General Psychiatry (Pedersen et al. 2012) which looked at a cohort of 45 788 women in Denmark who gave birth between 1992-1995, and found a statistically significant association between self-directed violence (including suicide attempts) in these women and their antibody titre to Toxoplasma gondii at the time of birth. The risk in seropositive women was 1.53 times greater than the risk in seronegative women.
Toxoplasma gondii is a parasite that is shed in the feces of cats, which are the parasites definitive host. Most house cats only ever shed significant amounts of the parasite the first time they're exposed to the parasite (typically when they're young). Depending on where people live and various cultural practices, transmission of the parasite from scooping out litterboxes may actually be relatively uncommon compared to other possible sources including exposure from soil (e.g. working in the garden and then not washing one's hands), eating unwashed vegetables, or eating some types of undercooked meat.
The most glaring limitation of the Pedersen study is that they didn't control for any other factors that may have resulted in the women who committed acts of self-directed violence being more likely to be seropositive for Toxoplasma than others. For example, women with mental illness may be less likely to practice good hand hygiene (one of the most important factors for reducing the risk of parasite transmission), and therefore more likely to be exposed to Toxoplasma, or there may be other factors about their health or their lifestyle that make them more prone to infection. The point is the authors only found an association in a specific subset of the population (Danish women who had given birth to at least on child). This does not mean that the relationship is causative - they can't say that Toxoplasma infection makes people more prone to self-directed violence, only that women - in this particular group - who were seropositive for the parasite were also at increased risk for this kind of behaviour. It's a somewhat subtle but very important difference. The authors of the study clearly acknowledge the limitations of their work, but the news article does not do quite as good a job of pointing this out, until right at the very end where it does finally get mentioned.
Does Toxoplasma infection cause behavioural changes in rats that may make them more likely to wander into a cat's territory and be eaten? According to an experimental study it can, and it does make a certain amount of ecological sense that the parasite could have an effect on its intermediate host (the rat) that makes it more likely to be able to continue its life cycle (via being eaten by a cat) by reducing fear in the rat. Could infection of the brain in humans cause subtle behavioural changes? I can't deny the possibility, but humans are not rats and I would be very wary of extrapolating results from one species to the other. But is this parasite likely to "drive our brains off the highway" as the news article says? I'm not ready to buy that, certainly not based on this study. As the authors clearly state in the first line of the paper "Suicide is a tragic multifactorial outcome of mental illness, with complex biopsychosocial underpinning..." There are so many things that contribute to such an unfortunate outcome that a lot more work is needed before anyone can justifiably blame a "suicide parasite" in cats.
Whether you believe Toxoplasma infection can result in behavioural changes in people or not, there are some very simple steps everyone can take to help decrease the risk of becoming infected with this parasite regardless. These are particularly important for individuals who are immunosuppressed and women who are pregnant, because it is very well established that toxoplasmosis in these high-risk individuals certainly can have severe repercusions to either the individual or the unborn fetus. However, it is by no means necessary for such individuals to get rid of their cats if they take these simple precautions:
- Clean your cat’s litter box every day. The oocysts shed in cat feces usually take about 24 hours to become infective once they’ve been passed, so daily cleaning helps remove them before they reach this stage.
- Always wash your hands with soap and water after cleaning your cat’s litter box, after working in the garden or in any soil, and after handling raw meat.
- Keep your cat indoors. Outdoor cats are more likely to be exposed to Toxoplasma and shed oocysts in their stool.
- Keep sandboxes covered so outdoor cats don’t contaminate them with stool.
- Cook all meat, especially pork, lamb, mutton and wild game, to an internal temperature of 67ºC/153ºF or higher.
More information about Toxoplasma can be found on the info sheet on the Worms & Germs Resources page.
When I'm giving talks about zoonotic diseaes to people in the human healthcare field, I sometimes mention tuberculosis (TB) as an example of a serious human disease with poorly defined (but theoretically important) risks of transmission between people and pets. TB is a very important disease of increasing of concern because of its resurgence in many areas and the spread of drug-resistant strains.
We don't know much about TB and pets. There are some older studies that provide conflicting information, suggesting that Mycobacterium tuberculosis, the bacterium that causes TB, can be commonly or rarely isolated from dogs owned by TB patients.
A recent study from South Africa (Parsons et al. Research in Veterinary Science 2012) provides more information. The study involved two main components:
- For the first component, they examined 100 stray dogs in Cape Town, South Africa, for evidence of TB. The dogs were being euthanized for population control purposes so the researchers were able to do necropsies (post-mortem exams) to look for the bacterium and signs of disease that may not have been outwardly apparent. They isolated the bacterium from 4% of the dogs, with only one of those having any signs of disease. That shows that TB is present in dogs in the area, albeit at a low rate. The fact that 3 of 4 TB-positive dogs had no evidence of disease is both good and bad. It's good for the dog's health that illness doesn't always occur (just like in people), but it also means that apparently healthy dogs can be carrying this concerning bacterium. The risk of transmission from healthy carriers isn't known. It's probably rather low since close and prolonged contact are required to transmit TB between people, and healthy carrier dogs are probably not shedding many TB bacteria through their respiratory tract. Greater concerns are probably present in dogs with TB infection of the lungs who are coughing and spewing TB bacteria into the air.
- The second component of the study involved testing of 24 dogs living with people with TB. They used two different tests: the TB skin test (a test that's commonly used in people but one that's been typically considered useless in dogs) and an interferon gamma release assay (IGRA)(a test more commonly used now in humans). They concluded (not surprisingly) that the skin test was pretty useless, but their data suggest the IGRA may be a good test for dogs. 50% of dogs in those households had evidence of TB exposure through IGRA, consistent with one older study that indicated transmission of TB from people to pets may be common.
What are the implications of all this?
For the average person and pet, not much. TB transmission requires close and prolonged contact with an infected individual. You don't get it walking down the street behind someone with TB.
The concern is in situations when people with TB may have contact with pets - the same concern as in situations when people with TB may have contact with other people. The potential for transmission is something to pay attention to in households where there is an infected person, or in populations where there may be high TB rates and common pet contact (e.g. some homeless populations).
Results of this study should be a reminder that when considering who's potentially been exposed to a person with TB and making plans to reduce the risk of transmission, you need to consider all individuals - human and animal - with which the person has contact. Therefore, measures taken by people to avoid transmission of TB to other people should be equally applied to reducing transmission to pets. Pet exposure should always be considered, particularly when dealing with multidrug-resistant (MDR) or extensively drug-resistant (XDR) TB, since such strains are huge concerns in people and we don't want to create canine or feline vectors of these strains. The study results also indicate that pets owned by TB patients may be at increased risk of disease from TB, not just at risk of being infected and harbouring the bug. Therefore, knowing that a pet has had close and prolonged contact with a person with TB is relevant to veterinarians when evaluating sick animals.
Markham, Ontario's city council has passed a bylaw prohibiting the keeping of African Dwarf frogs. While in reality more of a ban on the sale of frogs in the city (since I doubt there will be any effort to search for contraband frogs in households), and perhaps of somewhat limited impact because of the availability of the potentially Salmonella-laden critters in neighbouring areas, not to mention the common practice of pet retailers flouting laws like this, it's nonetheless a step that will hopefully reduce the number of these animals in households.
Why the fuss about African Dwarf frogs?
- Mainly, it's because of the risk of transmission of Salmonella from these frogs to people. Large numbers of Salmonella infections have been linked to these frogs internationally, and the risks are amplified with pets like this that are marketed toward young kids (especially as pets to keep in their bedrooms) and for schools and childcare facilities, because children are one of the highest risk groups for developing salmonellosis.
- The other important issue is animal welfare, since these frogs are often sold in unsuitable habitats and have a fairly limited lifespan in captivity.
Not surprisingly, the owner of the US company that is one of the main distributors of these animals is unhappy with the decision. It's hard to be sympathetic given the fact that they essentially ignore the risks these animals pose to people, at least in the materials they present to the public. Despite the fact that they are marketing what is considered a high-risk animal as a pet, there's little effort put into providing information about that risk or risk mitigation. Looking at their promotional materials, I can find lots of information about how to care for the aquarium. Yet, none of it mentions Salmonella. There's no statement about keeping young kids away from frogs. There's no mention of washing hands after contact with frogs or their environment, or that aquarium water shouldn't be dumped down bathroom or kitchen sinks... or any other basic, relevant infection control practices. They do have some CDC information on their website if you look around, which is better than nothing, but it needs to be more prominent. Everyone that purchases one of these frogs should get a clear information sheet that explains the risk of Salmonella transmission and how to avoid getting sick. Yes, it puts a bit of a damper on the new pet, but a lot less than being hospitalized.
Back in Markham, it's hard to say whether the ban will have an impact on frog ownership because of the ability to buy frogs a few minutes away in neighbouring municipalities, and the likely lack of any real enforcement effort. However, it's a start and if nothing else, and publicity associated with the ban may help educate people. African Dwarf frogs that are already in households are exempt and can live out their natural (albeit often short) lifespans, but people can't replace them when they are gone.
More information about Salmonella can be found on the Worms & Germs Resources - Pets page. We don't have a dwarf frog info sheet (it's coming) but most of the information on the Reptiles info sheet equally apply to frogs.
'Tis the season...
As summer progresses, mosquito-borne infections become more common. While West Nile virus typically peaks later in the summer or early fall, Eastern equine encephalitis (EEE), a much more deadly viral neurological disease, tends to start cropping up earlier in the season.
Recently, EEE was diagnosed in two horses in Horry and Marion Counties in South Carolina, where the virus is mainly transmitted by a type of swamp mosquito, commonly known as the blacktailed mosquito. The outcome isn't stated in the report, but most likely the horses died, since mortality rates for EEE are extremely high.
Finding EEE in a region indicates that the virus is circulating in the bird and mosquito populations. Knowing this is important for a couple of reasons:
- It means that horses might be exposed to the virus by mosquito bites. Therefore, it's a good idea to reduce mosquito exposure by a variety of methods. Vaccination also needs to be considered, but given the fact that vaccines don't protect horses immediately, waiting until the first cases of the year are diagnosed may be too late. Ideally vaccination should be performed a month or so before the time when exposure is likely.
- It also means that humans may be exposed to the virus in the same way - by mosquito bites. EEE in humans is rare but devastating. If EEE is in an area, people need to take proper mosquito bite prevention measures. There's currently no vaccine against this virus for people. People cannot get EEE directly from horses or birds.
Horse owners need to be aware of infectious disease risks for their area (and anywhere they may take their horses), and they need to talk to their veterinarian about the risks and risk mitigation. Not every horse in North America requires EEE vaccination, but in some regions it's very important and should be a core vaccine.
Travel always carries a risk of infectious diseases. More people are paying attention to their health and going to travel clinics to find out about these risks and what preventive measures they can take. They still constitute only a minority of travelers, but it’s an improvement. There aren’t travel clinics for pets, so travelers thinking about pets and infectious diseases need to rely on sources like their regular veterinarians and government websites.
Unfortunately, that doesn’t always result in good information, as shown in a study recently published in Zoonoses and Public Health (Davidson et al 2012). For the study, the authors called veterinary clinics in eight European countries (Austria, Belgium, Finland, France, Germany, Sweden, Switzerland and the UK) and asked them about taking a dog to Norway. They also called clinics in Norway and asked about bringing a dog to the country from an unspecified location in Europe. Calling was done not as a research survey but by a person pretending to be a pet owner.
The study focused on two main pathogens, Echinococcus multilocularis (a tapeworm that is present in some parts of Europe but not others, and one that is both an animal and public health concern) and rabies. Only 9% of clinics provided accurate information about these two problems. Some clinics (58%) referred people to government sites that have good information, but unfortunately 13% of clinics referred people to websites or government agencies that provided incorrect or incomplete information. When information from websites is included, people received correct advice 62% of the time. Not bad but not great.
Among the bad advice that was given (or important information that was not given):
- Failure to tell people about the requirement for tapeworm treatment after arrival.
- Incorrect tapeworm treatment information.
- No mention of rabies titre testing.
- False information that pets traveling to Norway don’t require tapeworm treatment.
This shouldn’t be taken as indicating that veterinary clinics aren’t competent. Travel medicine certainly isn’t something I was taught in vet school. Most veterinarians (understandably) don’t spend much time reading about problems that only occur in other geographic regions, since there’s enough other new information on which they must stay current. So, they may not have answers at the tip of their tongues when asked a question. Trying to get good information by random phone calls or as an aside during a veterinary appointment might not be the best approach. However, since we have a surprisingly mobile pet population, with pets traveling with owners to many different regions, it’s an important area for veterinarians to think about, from two standpoints:
1) Counseling people who are traveling: As was the focus here, it’s important for people to know about disease risks and regulatory requirements for places to which they travel. Specific preventive measures (e.g. vaccination, deworming) that are not needed at home may be indicated when traveling.
2) Diagnosing disease in returning animals: It’s easy to miss travel-associated diseases, and that can lead to bad outcomes. If veterinarians don’t ask whether a pet has traveled, they won’t realize that there might be some other diseases to consider. If they don’t know about disease concerns in other regions or (perhaps more importantly) don’t have ready access to good information about disease risks in other regions (e.g. accurate websites), they might not consider important diseases even if they ask about travel history.
This study highlights a few of the current gaps in the system, involving background knowledge, client communications and variable accuracy of electronic sources. People who are traveling with pets (or acquiring pets from abroad) should have a thorough discussion with their veterinarian (not just a casual call to the veterinary clinic, during which information may come from or through lay staff) about the situation, and they need to do their own homework. It's probably best to make sure the clinic knows that there will be travel questions in advance, so mentioning it at the time of booking the appointment might help.
As the authors of this research state “An accessible, centralized, easy to use website, that is updated by a central regulating agency and applies to all countries, would allow veterinarians to refer pet owners to one site for further information regardless of which country they are travelling from and going to.”
That's the ideal situation. Given the minimal attention that governments pay to pet animals, it's probably going to have to be an government-independent, collaborative venture. We've had some discussions about this in the past and it would be great to do, but the logistics are a bit daunting. Maybe it's time to resurrect those discussions.
This time of year, it's very common around here to see young raccoons wandering about. It's also still pretty common to hear about people keeping a litter of baby raccoons in their house. I can understand the appeal - they're cute and entertaining. However, in addition to being illegal in many regions, handling young raccoons also poses a risk of exposure to a variety of infectious diseases.
Chief among the infectious disease risks of handling young raccoons is rabies, as a Walker County, Alabama, family found out. Two baby racoons were found in someone's attic, and another two littermates were found a little while later. The person who found them gave two each to two separate people. As is often the case, they were handled by many different individuals before one of the raccoon kits was found to be rabid. Now more than 20 people are facing post-exposure treatment. It's one of the larger reported exposures from a single rabid raccoon, but it's far from unprecedented.
Beyond the obvious public health concern, this situation demonstrates another possible issue. Rabies is sporadically distributed in some regions, and moving wild animals around leads to the potential for dissemination of rabies, as well as other infectious diseases. Raccoon rabies is present in the area where the baby raccoons were found, but has not been found in Walker County, even though it's not far away. If the rabid raccoon had escaped (or was released), it could have potentially spread rabies into an area where it's currently not well established, thereby increasing the risk of exposure to everyone (animals and people) in the county.
As mentioned above, it's also illegal to harbour wildlife in many regions if you are not a licensed rehabilitation facility. While getting fined seems to be uncommon, four people in this incident have been charged with unlawful possession of a protected animal. Just one more reason not to do this.
While baby raccoons may have some appeal, as Alabama's state veterinarian Dee Jones says, "...people just need to stay away from them."
Israel's Health Ministry is recommending rabies vaccination for people traveling to India.This seems to be mainly in response to the recent high-profile case of an English woman who died of rabies acquired from a dog in India. While it was high-profile, that certainly wasn't the only travel-associated rabies infection in the past year. Rabies exposure is a serious concern for people who might encounter dogs (intentionally or accidentally) while traveling in countries with endemic canine rabies. The news report states that rabies vaccine is available at clinics in Israel for would-be travelers, however it doesn't say whether the cost of vaccination is covered by the government. Human rabies vaccination is quite expensive, which may be a limiting factor when it comes to convincing travelers to get vaccinated, unless the government foots some or all of the cost.
Raising awareness of the problem with rabies in some developing countries is good. Most people don't really think about travel-associated disease (beyond the ubiquitous diarrhea that comes with travel to some areas), particularly something like rabies. In addition to focusing on vaccination, however, it would be even better to see a broader initiative to remind people to avoid contact with stray dogs (and other animals) and to make sure they get proper medical care after potential rabies exposure. Also, while India is certainly a hotbed of canine rabies, it's important to remember that there are many other countries where dog rabies is a major problem, and similar measures need to be taken for travel to these places too.
A surprisingly large number of people get sick and die every year from diseases acquired during travel. Travelers need to be aware of disease risks in areas they visit, know what preventive measures they should take and how to get proper medical care in any region they visit. While thinking about this might put a damper on vacation planning, it's worth the effort. When it comes to rabies, unless you know that a region is officially (and truly) rabies-free, assume that any encounter with a wild mammal, especially a stray dog, could be a source of rabies exposure. You don't want to travel in a bubble and stick to sterile locales, but you also don't want to come down with a fatal disease when some basic precautions could have prevented it.
While rabies is classically transmitted from animals to people by bites, any situation that allows saliva from an infected animal to get past the body's protective skin barrier can result in infection. Graeme Anderson, a 29-year-old South African canoeist, recently died after contracting rabies from a sick dog for which he was caring. There was no history of a bite, but the dog had licked damaged skin on the man's hands, allowing the virus to enter the body.
Any contact with animals showing signs consistent with rabies needs to be investigated. Licks over damaged skin (or mucous membranes like the mouth) are classified by the World Health Organization as having the same level ("severe") risk of rabies exposure as bites, and post-exposure prophylaxis is indicated. Bites are the main source of rabies transmission, but not the only source, the fact of which situations like this remind us.
Plague cases tend to get a lot of press. The fact that this disease killed a large percentage of the human population in a few different pandemics (albeit centuries ago for the most part) probably plays a role in that. Despite the impression by some that it's just a historical disease, plague is alive and well in certain parts of the world, including parts of the US, and infects a few thousand people every year.
Plague is caused by the bacterium Yersinia pestis, which lives in various wild rodents and is circulated by fleas. Transmission to people historically has been via fleas that jump from rats to people. However, plague isn't just a rat-human disease, as it can infect other animal species. Among domestic animals, cats seem to be most commonly infected, probably because of exposure while hunting.
The problem with plague and pets has been shown once again a case of plague in an Oregon man who likely picked up the infection from his cat. (Oregon is outside of the main range of plague in the US, where the disease is most common in the southwest). The man was bitten by the cat while retrieving a dried, decayed mouse carcass from its mouth. He developed septicemic plague (infection of the bloodstream), and then pneumonic plague (infection of the lungs), which is the worst case scenario. At last report, he was in critical condition and the prognosis for survival is probably guarded.
There's no mention of the cat's health. Most cases of cat-human plague occur in people taking care of sick cats (especially veterinarians). If a person is infected by a cat bite, I would expect the cat to have been sick with plague, although transmission has been reported from apparently healthy cats. Some other possible routes may need to be considered. If the cat in this case was exposed to plague, then plague's obviously in wildlife in the area, so you have to consider that the infected man might have been bitten by an infected flea (that came directly from an infected wild animal or that the cat tracked in) or from direct contact with wildlife, especially if his house had a rodent infestation.
Regardless, it's important for people in plague-endemic (and neighbouring) areas to be aware of plague and take measures to reduce the risk of exposure for themselves and their pets, such as:
- Avoid contact with wild rodents (and wildlife in general, since larger wildlife species can also be infected).
- Keep cats inside.
- Don't let pets with outdoor access roam unobserved, where they might be more likely to encounter wildlife.
- Have a flea control program for pets.
- Address any animal/household flea infestations promptly and aggressively.
- Make sure sick pets get prompt and appropriate medical attention, since diagnosing plague in a pet may be a critical factor in prompt treatment of people infected by the pet. Plague is an example of a disease for which diagnosing infection in the pet might save the owner's life.
Today's Toronto Star has an article about a reptile club in a Toronto Elementary School. Teacher Jim Karkavitsas runs a session every day that teaches students about a range of reptiles. His menagerie has expanded from one snake five years ago to more than 40 different species in his classroom. Some are loaned out to other classroom's on request and two lizards now make their home in the school's main office.
- Learning about, and interacting with, animals can be very important for kids, especially those who don't get exposure to animals at home and outside of school. It can teach responsibility and empathy, and be the springboard for a range of educational discussions.
- The animals are kept in a room adjoining the classroom, so they are relatively contained and all students aren't forced to be around them (since some kids might be afraid of them). Housing the reptiles in a different room also means students presumably aren't eating in the same room in which the reptiles are housed.
- Kids use hand sanitizer before and after contact with reptiles. This is a very important preventive measure for the problems outlined below, but it's not 100% protective (or usually performed all the time or done properly).
- Mr. Karkavitsas takes the animals home during the summer. A problem with some classroom pets is people don't assume ownership for them to take care of them properly when school's not in session. Similarly, the school's parent council provides $5000 to cover the cost of keeping the reptiles. Hopefully, that also means that veterinary care would be provided if something happens, which can be a problem in many cases when classroom pets need care but no one has a mandate to arrange or pay for it.
The bad and the ugly
- Salmonella. That's the big one. Reptiles are classic sources of Salmonella. You can almost guarantee that more than one of these reptiles are shedding the bacterium. If a reptile is shedding Salmonella in its feces, it will also likely have the bacterium on its skin, in its cage and in any areas where it roams. It also means that anyone touching it (or its environment, or contaminated areas) can pick up Salmonella on their hands, with subsequent transfer into the mouth. This is a high-risk situation since reptiles are a major source of salmonellosis, especially in kids. Reptile-associated salmonellosis does occur in classroooms.
- Mr. Karkavitsas buys frozen rats to feed the snakes. Frozen rats can also be contaminated with Salmonella, and frozen rats have caused salmonellosis in kids in a school (which was also brought home and spread other family members). There's also been a large (and likely ongoing) international salmonellosis outbreak associated with frozen rodents.
- Standard recommendations are that children less than five years of age (along with pregnant women, elderly individuals and people with compromised immune systems) not have contact with reptiles. This is a grade 5-6 classroom, so the students would be older than this, but I wouldn't be surprised if younger kids in the school also have contact with the reptiles. Additionally, the immunocompromised group is an issue, since many people have compromised immune systems due to various diseases or treatments. Teachers may not know about all of these and parents may not realize that their high-risk child is having contact with high-risk animals in school. When you can't be sure that high-risk people won't have direct or indirect contact, that's a problem.
The sentiment is great and I applaud the teacher's efforts to engage kids and teach them about animals, However, it's a cost/benefit situation and the potential costs (which may be extreme) outweigh the benefits (significant as they may be). While reptiles can be great pets in certain situations, they're not meant for schools where there are lots of kids, challenges with supervision, difficulty implementing good infection control practices and potentially individuals at high risk for infection.
It's not the first, and it's a safe bet it's not the last, but a lawsuit has been filed against Diamond Pet Foods in response to a case of salmonellosis in a New Jersey infant. The lawsuit claims (probably correctly) that the infant acquired Salmonella from contaminated dog food that was in the household. The infant was hospitalized for three days but recovered. The lawsuit, one of at least eight that have been filed, claims negligence and fraudulent representation, and is seeking over $75000 in compensation.
In reality, it's hard to consider a company liable simply for Salmonella contamination. Various practices can be used to reduce the risk and to detect contamination when it occurs, but these will never be 100% effective. Standard hygiene practices that are recommended to reduce the risk of exposing people (especially high risk people) to any pathogens that might be found in pet food must therefore always be used. It's hard to say what degree of responsibility needs to be placed on consumers versus companies, since companies need to do their best and people need to use common sense.
From my completely non-legal standpoint, the issues of negligence and liability come in when:
- A company has inadequate facilities that do not conform to standard requirements to reduce the risk of contamination (e.g. duct tape and cardboard in food processing equipment, as per the FDA report).
- A company has an inadequate quality control program.
- A company knows there's a problem and doesn't take prompt and appropriate action to correct it.
Based on what information has been released (including the relatively damning FDA report that cited lack of microbial analysis of certain ingredients, lack of hand hygiene facilities and the use of duct tape, cardboard and other non-cleanable materials in the plant) combined with some questionable communications strategies, it certainly seems like a case can be made here.
People like to talk about "one medicine" a lot. It refers to the concept that we're all animals, and that human and veterinary medicine should be one big happy family of healthcare providers that maintain the health of the entire family, human and non-human. I get a bit jaded talking about one medicine because there's a lot of talk but it's hard to get a lot of action. One problem is that while some people in both human and veterinary medicine are strong supporters of the one medicine concept, it doesn't always filter down to the ground level.
A study in the latest edition of the Journal of the American Veterinary Medical Association (Hill et al. 2012) presents some concerning but not surprising information about "Tennessee veterinarian and physician attitudes, knowledge and practices regarding zoonoses prevention among animal owners with HIV infection or AIDS."
The study consisted of a survey sent to 454 vets and 1737 physicians in Tennessee. Response was pretty poor (a common problem with surveys), with only 43% of vets and 15% of physicians completing it. You have to wonder why the physician rate was so low. One potential issue is that the topic is not even on the radar of most physicians so they didn't bother to respond. If that's the case, then the people who responded could be more interested than average, potentially biasing the results (meaning that the problems described below are actually underestimated).
Here are some highlights from the study:
73% of veterinarians, but only 50% of MDs, said that veterinarians should always or almost always be involved in advising clients with HIV/AIDS about zoonotic disease risks.
- Considering a large percentage of physicians don't initiate the discussion and don't get any additional education in zoonotic diseases (see below), I'm not sure what the other 50% of physicians think should be happening in terms of zoonotic disease counseling.
58% of veterinarians had zoonotic disease educational materials available in their clinics compared to only 3.5% of MDs.
- Not surprising at all. Actually, the fact that some MDs have info in their offices is a bit of a surprise.
Only 5% of MDs had any continuing education (CE) on zoonotic diseases in the past three years, compared to 29% of veterinarians.
- Pretty pathetic numbers all around. Veterinarians probably have easier access to this kind of CE since zoonotic disease topics are commonly presented at veterinary conferences, although attendance tends to be limited (as evidenced here). It would be nice to know why almost no MDs have had CE on zoonotic diseases. Is it lack of interest? Is it lack of availability? These are two completely different issues that can be addressed differently.
Almost 70% of veterinarians reported regularly talking to pet owners about the risk of zoonotic diseases in people with compromised immune systems.
- One problem here is knowing with whom to have the talk. Asking people their medical history isn't (logically) part of the normal pet examination process, and while it's good information to have, veterinarians aren't going to cross that line and routinely ask those types of questions. That raises the question about how to initiate the discussion, and a crucial factor is having pet owners who are willing to bring up the subject. For that to happen, they need to realize that it's relevant, that the veterinarian knows something about the topic and can help, and that all information will be treated confidentially. Therefore, client education is key.
51% of physicians said they never see zoonotic infections in HIV/AIDS patients, while 44% said they almost never see them.
- In part, that's a testament to the effectiveness of highly active anti-retroviral therapy (HAART), which has had a tremendous impact on management of patients with HIV. However, it also may be an indication that MDs don't recognize some infections as zoonotic. Certainly, a patient with Salmonella would (hopefully) result in some thought about zoonotic transmission, but there are a range of other pathogens where the zoonotic risks are less clear or less well known. When you consider that 71% of MDs never or almost never ask HIV/AIDS patients about pet ownership and animal contact, you can see how discussion and consideration of zoonoses might be poor.
Only 26% of veterinarians and 33% of MDs were able to correctly identify zoonotic pathogens of greatest concern to people with HIV/AIDS.
- Pretty concerning numbers (especially among MDs, who do the diagnosing).
100% of MDs never or rarely contacted vets about zoonoses, and 97% of veterinarians never or rarely contacted physicians.
- For all the talk about one medicine, this shows how far we have to go.
We need to do a better job of actually practicing one medicine. Veterinarians and MDs need to communicate. Both groups need to realize that they play a role in zoonotic disease prevention, and that the other group has an important role as well. Zoonotic diseases is a niche field in human and veterinary medicine but that doesn't mean they should be ignored. While serious zoonotic diseases are uncommon, they occur, and the failure to actually practice one medicine means that some people are at higher risk than they should be, and infections that occur may not always be identified and managed optimally.
Image credit: UI News Bureau (click for source)
While I guess it's getting beyond the point where Hendra virus infections in horses in Queensland, Australia are considered "news," it's still a highly concerning situation. Infections caused by this fruit bat-associated virus continue to occur in the region and there's no sign that this problem is going to go away any time soon.
In the latest report, two horses from a farm where a horse recently died of Hendra tested positive for the virus. In another location, a dog is being re-tested after a weak positive test. This situation brings back memories of the debate that occurred last year after a healthy dog that tested positive was euthanized as a precautionary measure, despite no information about whether the dog could actually be a source of infection.
Hendra is resulting in profound changes in the horse industry in Queensland. Beyond being a major problem in horses, this virus can be passed from horses to people, resulting is tremendous concerns amongst horse owners and veterinarians. Many veterinarians are refusing to work with horses because of the risk and I assume that some people are selling horses for similar reasons.
Infection control practices can presumably reduce the risk of transmission of Hendra virus between horses and from horses to people, but there's no way to completely eliminate the risk. Fruit bat control strategies get discussed, ranging from removal of fruit trees from horse pasture to reduce fruit bat exposure (logical) to fruit bat culls (highly unlikely to have any longterm effect). At a minimum areas under fruit trees should be fenced off from horses, and it has also been recommended to keep water troughs covered to prevent contamination with excrement from the flying foxes. Ultimately, everyone's holding out for an effective vaccine, which has yet to appear, but work on the vaccine is well underway and the hope is that a commercial vaccine could be released as early as next year.
An inquest into the dog-bite-associated death of Gary Dickinson, age 57, is underway in the UK. When people think about deaths from dog bites, they usually think about death from severe trauma, especially in kids. However, as I've mentioned repeatedly, minor bites can also pose major risks.
Mr. Dickinson died in February, only three days after being nipped in the finger while breaking up a fight between his dogs. It was a minor bite that many people would quickly dismiss. However, trauma isn't the only possible problem with bites. Infections from bites can be very serious, and in some situations all it takes is a very small break in the skin to allow bacteria to move into the tissues.
Despite suffering no consequences from the initial trauma of the bite, Mr. Dickinson was feeling sick by the next day. He went to the hospital and was sent home with a diagnosis of food poisoning (probably based on vague signs and lack of any other obvious diagnosis, rather than any true evidence of food poisoning. A key question here is whether the dog bite was mentioned at the hospital, which is unclear to me).
Mr. Dickinson deteriorated rapidly after returning home and was rushed back to hospital. Despite aggressive treatment, he died just six hours after admission. The diagnosis was Capnocytophaga infection, and this is a pretty classic picture of this rare but devastating infection.
Capnocytophaga is a type of bacterium that is found in the mouths of dogs. Pretty much every dog has loads of it in the mouth, and people are very commonly exposed through contact with saliva. Fortunately, it rarely causes infections and usually is only a problem in people with compromised immune systems. People who do not have a functional spleen (typically because it has been removed for one reason or another) are the classical high risk group for Capnocytophaga infection. Alcoholics are another high risk group, and that appears to have been the issue in this case.
Minor bites are usually just that - minor. However, sometimes very bad things can happen following very minor bites. Serious consequences are most common in young kids, the elderly and people with compromised immune systems (especially people who have had their spleen removed). While no one should panic after a mild bite, everyone should take any bite seriously. In most situations, thorough cleaning of the wound is adequate, but bites over critical areas (e.g. face, joints, hands) or in high risk people need to be assessed promptly by a physician.
More information about bites can be found on the Worms & Germs Resources - Pets page.
The title from Food Safety News' latest report says it all: "After eight expansions, how big is the Diamond Pet Foods Recall?" It's disturbing that we can't answer that question, considering the contamination stretches back to 2011 and now it's apparent that there are problems with another one of their plants.
Accordingly to Food Safety News, the FDA has indicated Salmonella contamination has been found in Diamond's Meta, Missouri plant, in addition to the South Carolina plant that's been at the heart of the recall. However, the Missouri Salmonella contamination is from Salmonella Liverpool, a different strain from the South Carolina plant where Salmonella Infantis has been involved. So, there's no evidence that the two recalls are linked, although you have to wonder whether deficiencies that were found by the FDA at the South Carolina plant might also be present at other plants, thus creating an increased risk of Salmonella contamination.
Anecdotal information about sick animals and people associated with this recall abounds, in stark contrast to information from Diamond Pet Foods. It would be nice to have some clear communication from the company about this outbreak, and some information about what they are doing to control it and prevent it from happening again. The continued expansion of the recall and contamination is concerning, and in the absence of clear communication from the company it's hard to have confidence in the safety of any more of their products.
A 50-year-old UK woman, the first of two recent travel-associated rabies cases in the UK, has unfortunately but not surprisingly succumbed to the infection.
The woman was bitten by a puppy while traveling in India. Given the widespread nature of rabies in dogs in India and the large number of human rabies deaths associated with canine rabies there, this was a high-risk exposure. I still haven't seen any information about whether she sought medical care in India or not. Too often, people don't bother to go to a doctor after being bitten, especially if the bite appears minor - but even a minor bite can transmit rabies. Furthermore, people don't always get the care they need, since rabies treatment is astoundingly not always offered after dog bites in India, and rabies vaccine and antibody may sometimes be in short supply.
Whatever happened in India, the woman was reportedly turned away twice by doctors back home at Darent Valley Hospital in Dartford, Kent. It's not clear why, and an investigation is underway, but it's not necessarily surprising since signs of rabies can be very vague at first. Initial signs could mimic a range of minor illnesses, and if the doctors didn't know that the woman was bitten by a dog in India, rabies presumably (and reasonably) wouldn't be considered, especially since it's not present in the UK.
In what is hopefully a case of misquoting or misinterpretation, Dr. Ron Behrens of the London School of Hygiene and Tropical Medicine is quoted as saying that there is a 24 hour window after a bite when antibody treatment can prevent the virus from entering the nervous system. In reality, it's not that quick and the incubation period can be very long in some cases. Post-exposure treatment can be highly effective even if it's given well after exposure, as long as it's before signs of rabies occur. Prompt treatment is always best.
It's apparent that there's an ongoing outbreak of LDDD, a potentially fatal dog-associated problem in people in this area. It seems to be a seasonal disorder, with nice weather bringing out more cases. I've seen a couple nasty cases in the past 24 hours, including one tonight that could have resulted in the deaths of an entire family.
What is LDDD?
A new bacterial infection? No.
A new virus? Nope.
Contrary to the focus on this site, it's not even an infectious disease. It's lap dog/dumb driver syndrome.
Tonight's case was fairly classic, involving the driver of an SUV and a small dog...on the driver's lap with its head out the window. The driver had one hand (and I'm not sure how many eyes) on the dog, and the SUV swerved off the road, but fortunately not all the way into the ditch (or a pedestrian, cyclist or other vehicle).
In Ontario, it's illegal to drive while using a cell phone. Restraining a small (or not so small) dog on your lap has to be at least as distracting and it's far from rare. A little common sense goes a long way, but common sense isn't always that common.
Just as I was getting ready to write about a recent case of travel-associated rabies in the UK, a second suspected case has been identified in the UK. They're not linked and it's just a co-incidence that the two have been identified in a short period of time, but they highlight the potential risks of rabies during travel.
The first report is about a confirmed case of rabies in a woman in her 50s who was bitten by a dog in India. At last report, she was being treated in hospital, although the prognosis is presumably extremely poor if treatment was started after the onset of disease. Public health officials have investigated people who were in contact with the woman to determine who needs post-exposure treatment.
There's not much information in the most recent report, beyond the fact that a suspected rabies case was detected in a person in Leeds following a dog bite that occurred abroad. There's no information yet (at least that I've seen) about where the bite occurred, the condition of the patient or whether the person received medical care after the bite.
While travel-associated rabies is very rare, it's almost always fatal. It's almost 100% preventable too, and any cases that occur typically reflect a breakdown in knowledge, communication or medical care.
Knowledge/Communication: People need to know about rabies, and be aware that any bite from a mammal in a rabies-endemic area should be investigated as a potential rabies exposure. They need to know about the risk of rabies in areas they visit, and avoid situations that might lead to a bite. Travelers and non-travelers alike need to know to go to a physician after any bite and to ensure that rabies exposure is duly considered. Individuals traveling abroad need to know how to access the healthcare system where they are, communicate the problem and act as their own advocate to make sure things are taken care of properly.
Medical Care: With proper post-exposure treatment, rabies is almost 100% preventable. The problem is getting the treatment in a timely manner. Knowing to go to a doctor is one issue. Getting proper care once there is another, particularly in some countries where access to rabies vaccine may be limited or where the healthcare system is poor. Rabies exposure is a medical urgency, not an emergency (although the more severe the bite and the closer to the head, the more important it is for a prompt response). If someone has had a potential rabies exposure and they aren't getting proper care, they need to get home (or somewhere else) where they can obtain the appropriate treatment. That doesn't mean panicking and getting on the first flight out of the country, but it also doesn't mean waiting until your planned vacation is over. It means getting home in good time, while not freaking out if it takes a day or two.
There have been various news reports from different parts of North America describing distemper outbreak in raccoons. Distemper is a viral infection caused by canine distemper virus, which is related to the human measles virus (but the canine version can't infect people). A variety of animal species in addition to dogs can get distemper, most notably raccoons.
Distemper outbreaks are not uncommon in raccoons, and one big problem with distemper is that the neurological signs cannot be distinguished from rabies. Yes, there may be some general trends in how a raccoon with distemper behaves that differ from one with rabies, but it’s far from definitive. That creates issues because distemper is of absolutely no human health concern while rabies can be transmitted to humans and is almost invariably fatal.
A Windsor-Essex (Ontario) outbreak of distemper in raccoons highlights some of these issues and the care that must be taken with regard to public communications.
Authorities are “urging the Windsor-Essex public not to worry about a rising number of incidents with strange-acting raccoons: The poor scavengers are suffering from distemper, not rabies.”
- This is bad communication in my opinion. I’d rather see something like authorities are "urging the public the avoid raccoons because of the risk of rabies exposure, but to be aware that a raccoon that is behaving abnormally probably has distemper, not rabies." Telling people not to worry is okay, but making it seem like there's no issue whatsoever is another. No one can say for sure that all of these affected raccoons have distemper, not rabies.
A good statement appears later in the article ”(Executive Director of the Windsor-Essex County Humane Society Melanie) Coulter stressed that although the disease is highly contagious among animals, it can't be passed to humans. But she added that raccoons with distemper are still capable of sudden aggression, especially if they feel cornered. As well, the symptoms of distemper are similar to those associated with rabies -- and the difference can't be determined without lab testing.”
- That’s much better. It highlights the problem and explains that it’s probably not a risk to people, but also makes it clear that you can’t be sure it’s not rabies.
The key thing is avoiding contact with raccoons all of the time, with particular attention to raccoons that are acting abnormally, since they are more likely to have rabies and they can be unpredictable. Some other things to consider:
- Don’t keep raccoons as pets (common but illegal, at least here).
- Don’t encourage raccoons to live around your home.
- Keep pets away from wildlife.
- Ensure dogs (and cats) are vaccinated against rabies and distemper, in case they have an unexpected incident with a raccoon.
I’ve written before about infectious disease concerns associated with animal smuggling. It’s usually focused on the large-scale smuggling of reptiles, birds and other small critters, but it can happen in larger animals as well.
Some parts of the US/Mexico border appear to be rather popular smuggling routes for cattle and horses. US Border Patrol agents recently seized 14 horses that were being smuggled into the US across the Rio Grande River, south of El Paso, Texas. USDA officials tested them for a range of diseases and found that all 10 adult horses were positive for equine piroplasmosis, a potentially fatal bloodborne parasitic disease. This is an important disease that’s common in Mexico but has been considered a foreign disease in the US (although recent recurrent outbreaks make it clear that it is established in some parts of the country). Regardless, smuggled horses come in with no testing, no documentation, not contact tracing and no controls, so they represent a great way to either bring in new diseases or spread existing ones around.
In 2011, approximately 280 cattle and around 160 horses (including donkeys and mules) were seized along the Rio Grande. I’m not sure what percentage of smuggled animals get caught. However, it’s probably a minority, so it’s likely safe to assume that lots of horses and cattle make their way into the US as illegal aliens and potential disease vectors every year.
The large recall and salmonellosis outbreak associated with a variety of foods produced by Diamond Pet Foods continues to expand, in terms of species involved, the number of cases, the number of recalled products and geographic scope. The only thing that's not expanding in information from the company.
Reports (of varying strength) of Salmonella cases in dogs have been cropping up, but it's not just a US problem or a problem only involving people and dogs anymore. Two cats from a Montreal animal shelter have apparently died. At least two people in Canada have also been infected, one each from Quebec and Nova Scotia.
As with many outbreaks, the depth of information is variable when it comes to potential cases and it's hard to say if everything that's reported in the press is real. Just because an animal has been eating recalled food and gets sick, that doesn't mean that the food caused the disease. Testing is required to make the diagnosis of salmonellosis and confirm the involvement of the outbreak strain. However, enough reports are coming in to be fairly convincing that this is a very large, wide reaching outbreak involving people, dogs and cats, and multiple countries.
Communication is critical when managing an outbreak. It can let companies show they are doing everything that's necessary (and more), demonstrate their commitment to correcting the problem, show how they are helping people with affected animals, and provide confidence that once the problem was identified, it was (or will be) rectified and the product can be considered safe. Some companies shine during outbreaks. Some don't.
Here, communications don't seem to be ideal.
- Another product was added to the recall list, without too much publicity.
- We know recalled food is in the US, Canada and Puerto Rico (with sick people and animals in at least Canada and the US), but has contaminated food gone any further? Importantly, has information about the potential risk gone anywhere the food might have gone, since the FDA's mandate ends at the US border. eFoodAlert reports some concerning information in that regard. The Taste of the Wild website lists over 50 countries where the food is available and a correspondent for the site apparently bought a recalled product in Ireland. What is actually being done to correct problems that lead to the outbreak is also unclear.
- I also haven't seen any press releases from the company addressing the numerous FDA violations that were identified in the outbreak investigation.
Outbreaks happen. Sometimes they're not preventable. Sometimes mistakes happen. That's an unfortunate aspect of life. However, how a company deals with those issues, both in terms of correcting the problem and restoring consumer confidence, is critical, and seems to be lacking here.
A good adage when it comes to outbreak communications is "never announce a problem without announcing a solution." That doesn't mean hide outbreak information (something that is done too often). Rather, it means don't just say that you have a problem. Be clear about your problem and at the same time be clear about what you are doing to fix it. Hopefully, Diamond Pet Foods has an aggressive ongoing response to correct these problems, and that's what consumers need to know about. In the absence of any clear information, we're left wondering whether they are doing anything at all.
People might assume that diagnostic tests are created when researchers identify a condition that needs a new or better test, then develop the test and prove that it works (and helps with patient). However, sometimes it's more a matter of a new test looking for a market rather than a disease looking for a test. Sometimes, it's a matter of an old test trying to maintain a market in the face of new information or better testing. Whatever the situation, the bottom line is that not all available diagnostic tests are useful in all situations.
Bartonella testing is a good example. Bartonella is a strange Genus of bacteria that can cause various diseases in people. Of these diseases, the one most commonly associated with pets is cat scratch disease caused by Bartonella henselae. It usually causes only mild illness, but serious complications can occur, so it's something to which we need to pay attention.
National Veterinary Laboratory, a private diagnostic testing company in the US, is currently promoting their Bartonella test, an old test that only indicates previous exposure to the bacterium, as a way to keep yourself and your family safe. In their promotional materials, they state "We recommend that all healthy pet cats, especially those obtained as strays, from shelters or animal rescue organizations, and those that have had flea infestations, be tested for Bartonella infection."
It's not surprising that they recommend testing, since they make money off the testing. But what does the evidence say, and what do experts recommend?
They certainly don't say the same thing as the diagnostic lab. In fact, Guidelines for the prevention and treatment of opportunistic infections among HIV-exposed and HIV-infected children: recommendations from CDC, the National Institutes of Health, the HIV Medicine Association of the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the American Academy of Pediatrics states:
"No evidence indicates any benefit from routine culturing or serologic testing of cats for Bartonella infection or from antibiotic treatment of healthy, serologically positive cats."
So, if an independent group of experts doesn't think that testing of cats owned by this high risk population is necessary, why would we test every cat?
Why not test all cats? For me, it comes down to what the results tell me, and what I'd do with them. For this type of testing:
- A positive result means the cat has been exposed to Bartonella at some point, and may or may not be shedding the bacterium. There are no guidelines that recommend treating healthy cats, so I'd focus on flea control along with bite and scratch avoidance.
- A negative result means that the cat has probably not been exposed to Bartonella, but the test isn't 100% sensitive. It also only tells me the status of the cat up to the point that the test was performed, not it's future status. So, the cat could theoretically pick up Bartonella at any point. As a result, I'd 'd focus on flea control along with bite and scratch avoidance.
Why do a test if the end result is going to be the same either way?
Bartonella henselae (along with some other Bartonella species) is an important zoonotic pathogen which warrants our attention. However, what we need is greater awareness amongst physicians of Bartonella, better cat bite and scratch avoidance and better flea control practices for pets, not unnecessary testing of healthy cats.
Good diagnostic testing is critical for people and pets that might have disease from Bartonella, but not for healthy individuals.
Ichthyotherapy is a fancy name for sticking your feet in a bucket of doctor fish (Garra rufa) and letting them gnaw on your dead skin. While it's not something I'm planning on doing (for various reasons), it's a popular spa treatment in some areas. It's also spawned (pardon the pun) controversy because of infectious disease concerns. Specifically, spa "instruments" are supposed to be cleaned and sterilized between clients, but you can't really autoclave fish. (Well, you can autoclave fish... just don't expect them to do any more foot grazing when you're done.)
Some people have pushed back, saying there's no evidence that these fish pose any risk, although some infections have been reported. A paper published in the latest edition of Emerging Infectious Diseases (Verner-Jeffreys et al. 2012) provides some interesting new information. It involves an investigation in 2011 by the UK's Fish Health Inspectorate into an outbreak of disease amongst 6000 doctor fish that had been supplied to spas in the UK. The outbreak had a high mortality rate (amongst the fish, not the spa clients) and the bacterium Streptococcus agalactiae (a Group B Streptococcus species) was isolated from sick and dead fish. This bacterial species can cause a range of illnesses in people, but the strain that was found was most closely related to a strain previously found in a sick fish and is not necessarily a risk to people. However, it raised questions about the bugs that may be found in these fish.
Researchers followed this up by doing checks of doctor fish arriving at Heathrow Airport from Indonesia. A variety of different bacteria known to cause disease were isolated from the fish, including some multidrug-resistant bacteria. While it's not particularly surprising, this provides more evidence that most or all of these spa fish are carrying bacteria that can cause disease in people. When people put their feet in water containing these fish (and the fish feces), there's a chance of exposure. Disease seems to be rare, but it can happen, and the risk is probably highest is people with underlying skin disease, as well as people with compromised immune systems.
The easiest way to avoid these risks is to avoid ichthyotherapy. But, if you can't go without your foot fish treatment, how can you reduce the risk? There's no solid information but the following precautions and measures make sense:
- People with cuts, scrapes or other foot lesions should not undergo ichthyotherapy.
- People with diseases that affect their immune system (including diabetes) should similarly avoid close encounters of the fishy kind.
- Consideration should be given to commercially raising pathogen-free doctor fish for spa use under high standards of infection control and hygiene.
- Good management practices to deal with cleanliness of water and health of the fish should be developed and followed.
An Albany, Georgia woman is fortunately recovering from necrotizing fasciitis (flesh eating disease) that developed after a cat bite. The cat presumably wasn't the source of the bacterium that caused the disease, but it was the source of the wound that let the bacterium (usually Group A Streptococcus sp) get into her body in the first place, and from there the infection spread rapidly.
In this case, the woman was bitten on the hand by her cat. There's no mention of what she did after the bite, but often people don't take adequate precautions after cat bites because they can appear minor. While the trauma can be minor, cat bites are notorious for causing infections because they can drive bacteria deep into tissues, making it easy for infections to develop.
Four days after the cat bite, the woman's hand "blew up" and she was rushed into surgery. It's an emergency situation because death rates can be high, and those people lucky enough to survive can still have serious complications sometimes requiring measures as drastic as limb amputation, and the extensive tissue damage can lead to chronic problems for the rest of their lives.
People shouldn't worry about getting flesh eating disease from their cat (in part because people don't actually get this kind of infection from cats, it's just that bites can predisposed them to this (and other) kind of infection). However, people should be aware of potential issues associated with bites (from cats in particular, but also from any kind of animal). This case is just one more warning about a range of potential problems that can develop following a cat bite. Any cat bite should be taken seriously and at a minimum promptly and thoroughly cleaned. Bites that occur over the hands, feet, face, joints and similar high risk sites or that occur in people with compromised immune systems should be evaluated by a physician - and sooner rather than later. It's much easier and better to prevent an infection from developing than to try to control an established infection, and while most cat bite infections are mild, serious problems are far from rare.
More information about cat bites can be found on the Worms & Germs Resources - Pets page.
Two horses have been removed from the showgrounds after testing positive for equine influenza virus at the FEI show jumping event in La Baule, France. The horses were not showing any signs of illness but were positive on PCR testing (presumably from a nasal or nasopharyngeal swab) and were sent home, along with four other horses taken care of by grooms of the two test-positive horses. Organizers are also planning to isolate all the horses that were in the same stable block as the positive horses, but they will stay on the showgrounds.
Authorities were monitoring horses at this show after a confirmed case of equine influenza was identified at a horse in another recent horse show in France. The article states that "precautionary testing on some horse was undertaken" but it's unclear how horses were selected for testing. Was it random? Were horses that had been to the other show tested? Had the horses tested been in contact with those other infected horses?
Testing of all horses is an aggressive (and expensive) approach, but equine influenza is an ever-present risk at shows and it's highly transmissible, so it may have been decided that the time and effort was worth it to test at least some of the animals.
The two positive horses were healthy and may not develop influenza. The test that was used is highly sensitive and detects viral RNA. That means if the test is positive there is actually flu virus present in the horse, as opposed to blood tests that detect antibodies to the virus, which simply determine whether the horse has been exposed. Viral PCR tests can also pick up dead virus, but it's unlikely that a horse would have RNA from dead influenza in its nose in the absence of an infection.
Since these horses are currently healthy, there are a few possible explanations:
- They are incubating flu and will get sick soon. Horses can start shedding the virus before they get sick, which complicates influenza control.
- They could have had flu and recovered. However, since horses only shed the virus for a short time and it would be very unlikely for the horses to have been sick and recovered, and still be shedding the virus.
- The horses might be infected but developed a very mild or clinically unapparent infection. They might have had enough inherent or vaccine-induced immunity to prevent disease from occurring but not enough to prevent the virus from growing. Flu vaccines are designed to reduce the incidence and severity of disease, not viral shedding,
- It could have been a false positive lab test.
Is testing and exclusion of healthy test-positive horses overkill?
- No, I don't think so. It's certainly aggressive, but it is a reasonable approach to dealing with a concerning and highly transmissible infectious disease, although even so it won't eliminate all infectious disease concerns. People whose horses are excluded probably don't like it, but hopefully they see the greater good, meaning "what goes around comes around" (or more specifically when dealing with disease control "what doesn't go around doesn't come around," and hopefully their horses will have a lower chance of being infected in the future because of similar measures taken by other people).
I'm getting a lot of questions now about canine aspects of this recall, so I've addressed my take on some of the important issues below.
Can Salmonella cause disease in dogs?
Absolutely. The common myth about dogs being immune to Salmonella (mainly found on raw food sites) is just that: a myth. Dogs can and do get Salmonella infections, and it can make them sick.
Are dogs getting sick because of the recalled food?
I don't know but I suspect they are. There's no reason to think that the strain of Salmonella involved here would infect people but not dogs. The reason that there are reports of human but not canine cases could simply be because there is a formal surveillance and reporting system for humans but not dogs. Also, testing is not commonly performed on dogs with diarrhea, so large numbers of cases could go unidentified.
What would a sick dog look like?
The most common presentation of salmonellosis in dogs is diarrhea. Vomiting, lethargy and lack of appetite may also be present. Diarrhea can range from mild to severe and bloody. Chronic diarrhea can also develop but is less common. Other types of infections such as bloodstream infections can occur, with or without diarrhea, but these are pretty rare.
How do I know if my dog has salmonellosis?
The only was to know is to try to detect the Salmonella bacterium. This usually involves testing of stool samples. Culture is the standard and preferred approach, and is best done by a lab experienced with Salmonella testing and one where selective culture methods will be used. PCR, a type of molecular test, can also be used to detect Salmonella DNA. The quality of these tests (and the labs that offer them) is quite variable, but some of these tests are quite good. The downside is that all you find out with PCR testing is whether Salmonella is present or not. With culture, the bacterium can be tested further to see if it is the outbreak strain, and it can be tested for its susceptibility to antibiotics in the uncommon event that antibiotic treatment is needed.
My dog is healthy but has been fed recalled food. Should he/she be tested?
I don't recommend that. I only want to do a diagnostic test if I have a clear plan regarding how to use the results, which wouldn't be the case is a situation like this. If the dog was positive for Salmonella, I wouldn't do anything special except remind you to avoid contact with its poop (which you should be doing anyway). We don't treat Salmonella carriers - dogs that are healthy and shedding Salmonella will eliminate it on their own, usually within a couple weeks. A negative result also doesn't guarantee that the dog is truly negative. Usually we want multiple negative cultures to rule out Salmonella since it can be shed intermittently and can be hard to detect.
My dog is healthy but has been fed recalled food. Should he/she be treated with antibiotics?
NO. That's the last thing I want to do. Antibiotics are not very effective (or effective at all) at eliminating Salmonella that's living in the intestinal tract. A healthy animal shedding Salmonella is an indication that the body is handling it. It doesn't mean that disease won't occur, but one critical aspect for preventing intestinal infections is the protective effect of the gut microbiota - the trillions of bacteria that are in the gut helping suppress "bad" bugs like Salmonella. My concern with prophylactic treatment is that we might make things worse by suppressing this protective bacterial population and letting Salmonella overgrow in a situation where it otherwise would not have been an issue.
Fox / dog / human, North Carolina
In this case, a rabid fox had a "direct encounter" with several people, then it was killed by a dog. Three people have started post-exposure treatment.
- The article states that the dog was vaccinated against rabies, which is good to hear. However, it goes on to say that exposed pets need to be euthanized or have a 6 month quarantine. In reality, standard guidelines are that unvaccinated pets are treated like this while vaccinated pets undergo a less rigourous 45 day observation at home. Hopefully the discrepancy is simply due to inaccurate reporting and not misinterpretation of guidelines by local officials.
Cat / human, Maryland
A rabid stray cat scratched five people, who have been urged to undergo post-exposure treatment. Officials are calling for anyone who potentially had contact with this cat go to an emergency room.
- However, odds are if someone goes to an emergency room and says they might have had contact with this cat, they're just going to sit around until someone tells them they don't know what needs to be done, or to go home and deal with someone else. Rabies exposure is a medical urgency, not an emergency. People should take a little extra time to work with their physician and/or public health rather than go to the emergency room.
- People who may have had contact with the cat need a proper assessment to determine if they were potentially exposed to rabies, since just being around the cat or having casual contact is not a risk. Scratches are a bit controversial since they are low risk for rabies transmission (unless the scratches become contaminated with saliva from the animal), and there are conflicting guidelines regarding what to do for a person who is scratched.
- This is also a good reminder to stay away from stray cats.
Fox / human, Pennsylvania
In this report, authorities are trying to find a person that cradled an injured fox in a blanket. The fox was subsequently identified as rabid and they need to determine whether the person was potentially exposed to the virus.
- Again, another reminder to stay away from wildlife, and if there is contact with wildlife, make sure rabies exposure is considered.
Bat / human, Indiana
A student was bitten by a rabid bat while he slept in an Indiana University dorm room. He woke up after being bitten (good thing, since he probably wouldn't have noticed otherwise due to the often tiny marks left by a bat bite). He is now receiving post-exposure treatment.
Rabies isn't going away, at least any time soon. People need to be aware of the risks in rabies-endemic areas, take care around wildlife and vaccinate their pets.
Photo credit: Rob Lee (click for source)
Why the fuss?
VS is a viral infection that can affect a range of animals species. In addition to horses, it can infect cattle, pigs and sheep (and a few others). It produces painful blisters in the mouth and other areas that can result in decreased eating and drinking, lameness, severe weight loss and secondary infections. In food animals, it can cause severe economic losses. Another issue is that in cattle and sheep, it looks like the dreaded food and mouth disease. Lab tests can distinguish the two, but there can be a lot of angst when sorting out what causes vesicular diseases in cattle.
VS is a reportable disease in Canada and was last identified in the country in 1949. Import restrictions are a routine measure in response to the periodic US cases that occur.
In this case, the following restrictions have been implemented:
- Horses cannot be imported from New Mexico.
- Canadian horses that are in New Mexico must either get an import permit and supplemental USDA health certificate, or must be moved to another state for at least 21 days prior to returning to Canada. The supplemental certification indicates they've been evaluated by a veterinarian, have not been on a farm where VS was present over the past 60 days, and have a negative VS blood test. Horses that are moved to another state require a USDA certificate indicating that they've lived in that state for at least 21 days. (This may be complicated by restrictions implemented by other states on accepting horses from New Mexico.)
- All other horses coming from the US must be certified by the USDA as not having been in New Mexico in the past 21 days.
Image: Ulcers on the tongue of a horse infected by vesicular stomatitis (VS) virus. Image source: Colorado State University Extension
After starting off like a simple recall of potentially Salmonella-contaminated dry pet food, the Diamond Pet Food problem has now expanded into a multistate outbreak of salmonellosis in humans linked to exposure to the contaminated pet food. At last count, there were 14 affected people from 9 US states, including 5 who required hospitalization. These numbers could increase since so far they only include people who got sick up to April 1 (because it takes time for Salmonella to be grown in the lab, sent to CDC for testing and the result investigated, later cases may not have been reported yet).
This outbreak involves Salmonella Infantis, a strain that is uncommonly identified in people. Finding an increased number of infections caused by an unusual strain makes it easier to identify an outbreak, as was presumably the case here. This strain has also been isolated from various types of pet food that were produced at the Diamond Pet Foods' South Carolina plant. Despite the name, this strain of Salmonella is not more likely to infect infants, and people ranging from less than 1 year to 82 years of age have been infected.
Details about the types of contact people had with the pet food are limited. 70% of infected people reported having contact with a dog the week before getting sick. How the other 30% could have been exposed is unclear. Sometimes peoples' recall is poor, especially if they had transient contact with a pet. Individuals could have been exposed from environmental contamination when visiting a household where contaminated pet food was fed, without having direct contact with a pet. It's also possible some cases are not directly related to the outbreak and co-incidentally were exposed to the same strain from some other source.
Since we see periodic outbreaks associated with dry pet food, does that mean that other types of pet food are safer? Not really. Canned food is ultimately the safest because of the heat processing, but it's not practical for all animals.
Typically, after a report like this, I get a barrage of emails from people saying "See... we don't have large outbreaks from raw food diets so they are safer." Unfortunately, that's not the case. High pressure pasteurization (HPP) of raw food, a process that uses pressure with minimal heat to kill bacteria, is an effective method for reducing contamination of such products with harmful pathogens like Salmonella, and HPP is now being used by a couple of companies. These raw diets should be quite safe from a Salmonella standpoint. Otherwise, the risk of Salmonella contamination of raw pet foods is still very high, and if anything, the dry food outbreaks show how people can be infected from contaminated pet food.
Why don't we see large outbreaks associated with raw food? Outbreaks get detected because certain patterns or unusual findings are identified. Raw pet food associated outbreaks probably occur but are not as readily identifiable since raw meat contamination is common but involves variable Salmonella types that regularly change. In a situation like that, you can potentially have lots of people getting Salmonella from raw food, but if there is limited commonality in strains and products, it doesn't get picked up as an outbreak. That's particularly true when the strains that are involved are the common ones found in food, since they would often be dismissed on the premise that the person likely got it from some unknown food source. Without large numbers of cases in an area or a cluster of unusual strains, the investigation wouldn't likely get very far and nothing would be reported.
How do reduce the risk of getting Salmonella from pet food (or your pet)?
- Don't feed pets in the kitchen. This practice has been associated with an increased risk of disease in a previous outbreak of salmonellosis in children.
- Wash your hands after handling pet food.
- Don't let young children have contact with pet food.
- Use common sense when handling pet feces.
More information about both Salmonella and issues pertaining to raw diets (including how to reduce the risk) can be found on the Worms & Germs Resources - Pets page.
Botulism has been in the news lately, with numerous outbreaks involving different species and some human food recalls. Botulism outbreaks are often pretty dramatic because of the number of individuals that can be involved, the severity of disease and the fact that it's often difficult to do much beyond damage control once the problem is recognized. Recently, there have been reports of widespread duck deaths along with a couple of different recalls and warnings in Ontario about potentially contaminated smoked salmon and improperly eviscerated salted fish.
On the equine front, there's also been a large botulism outbreak that is believed to have killed 23 horses in Maine (USA). The outbreak occurred over the last month and, as is typical, has been devastating because of the profound susceptibility of horses to botulinum toxin and the inability to do much to save the animals once it was realized that botulism was present.
In adult horses, botulism is caused by ingestion of food that's been contaminated with toxins produced by the bacterium Clostridium botulinum, as it grows. This relatively widespread bacterium doesn't normally grow and produce toxins in horse feed since it requires an oxygen-free environment and other specific conditions, but when these occur, the incredibly potent neurotoxin can be produced. Equine outbreaks are often associated with haylage or silage (which if improperly fermented allow for C. bolulinum to grow) or contamination of round bales (e.g. an smaller animal that died of botulism gets accidentally incorporated into the bale, where the toxins can persist and/or the bacterium can grow if the right environment is present deep within the bale). In this outbreak, silage is suspected to be the cause. The silage is being tested to confirm this suspicion.
You can never 100% prevent botulism, since strange sources are sometimes found, but avoiding high risk feeds (e.g. silage, haylage, moldy round bales), trying to ensure that dead animals do not get caught up in hay bales during the baling process and taking exceptional care when baling if botulism is present in wildlife in the area can help greatly. A vaccine is available but it only protects against certain types of botulism. If those types are the main types that cause disease in a given area, vaccination can be useful, but good feeding practices are the most important preventive measure.
Image: Horses at a round bale feeder (source: www.omafra.gov.on.ca)
Recently, I've had a run of interesting advice calls about strange infectious diseases in dogs that have been imported from various countries. At a meeting the other day, I had some discussions with colleagues from across Canada who have also seen various infectious diseases in imported dogs.
Imported infectious diseases are a concern for a few reasons:
- Some could spread to other dogs in Canada.
- Some could infect insect vectors and eventually establish themselves in Canada.
- Some could pose a significant risk to people (e.g. rabies).
- Diagnosis of foreign diseases in pets can be difficult because Canadian vets may have little knowledge about them, and they just don't come to mind when evaluating a sick animal.
Some of these sick imported pets are animals adopted by people when traveling. Some arrive via organized rescue programs, both from the US and beyond (we'll leave the discussion about the ethics and economics of importing stray dogs from different regions when we have no shortage of them here for later).
One thing that strikes me as bizarre is how easy it is to import a dog from any country. I do a fair bit of international research and regularly import samples like nasal swabs and fecal samples from different countries, and it's more effort for me to get a nasal swab into the country than it would be to bring in the whole dog.
For example, if I want to get nasal swabs from dogs from a different country to test them for staphylococci, I need to:
- Submit an import permit request to the Canadian Food Inspection Agency (CFIA) (and pay).
- Submit a facility certification form to the CFIA signed by our Biosafety Officer.
- Submit an import permit request to the Public Health Agency of Canada (PHAC).
- Have a facility compliance letter from PHAC that's based on a long questionnaire demonstrating that I have adequate facilities, protocols and training, along with a facility inspection by our Biosafety Officer.
For me to import a dog, I need:
- Proof of rabies vaccination
That's it... unless I want to import a dog less than 8 months of age and not accompany it into the country, in which case I also need a health certificate (which in itself is not much of an indication that there's limited risk of infectious diseases).
Does that seem logical?
The CDC is investigating CDC is investigating more cases of salmonellosis associated with feeder rodent contact, caused by the less-than-catchy-named Salmonella I 4,,12:i:-. This strain is the same one that was implicated in a large and prolonged outbreak in the US and UK in 2009-2010 which was also associated with frozen feeder rodents (rodents sold frozen as reptile food) from a single US supplier. The current outbreak has affected people in 22 US states from August 2011-February 2012, and involvement of the same strain from the same source certainly leads to suspicion that this is actually an ongoing problem.
In the latest outbreak:
- 46 people have become sick. As is common, kids have borne the brunt of this outbreak, with the median age of affected persons being 11 years.
- 37% of affected people were kids five years of age or younger. Since this outbreak involved feeder rodents, clearly people aren’t heeding the guidelines that kids of that age shouldn’t be in households with reptiles.
- No two affected people reported buying rodents from the same store. This shows how widespread the problem is and that it must be originating from the place where the rodents are bred and/or distributed, not a focal pet store issue.
Record-keeping at the pet stores complicated figuring out the source. However, two breeders that supplied pet stores received mice from the company that was the source of the 2009-2010 outbreak. This suggests that not only were people exposed from frozen feeder rodents in the earlier outbreak, but that breeding colonies in different areas were infected from that source. This may have allowed wide dissemination of this Salmonella strain into numerous rodent breeding colonies, creating many possible sources of exposure for members of the public purchasing feeder rodents. The large-scale commercial nature of rodent breeding and wide distribution network creates a great opportunity for widespread outbreaks, as is apparent here and with various other outbreaks (including salmonellosis outbreaks from guinea pigs and baby poultry).
If you are going to buy feeder rodents:
- Treat them as if they are carrying Salmonella, because they just might be.
- Keep them away from human food. Keep them in a separate freezer or fridge, or in a sealed container if they have to be in the same fridge as human food.
- Don't handle them in the kitchen.
- Wash your hands thoroughly after handling.
- Keep them away from young children, as well as people with compromised immune systems, elderly individuals and pregnant women. None of these groups should have contact with reptiles either.
Image: A package of frozen rats, as sold commercially for feeding reptiles.
Identification of the strain of rabies in the first person in Toronto to be diagnosed with rabies in the past 81 years has essentially confirmed that the infection was acquired abroad. Toronto Public Health has indicated that the strain obtained from the infected man is one known to circulate in dogs in the Dominican Republic, where the man had been working over the past few months.
Little additional information is being released, including whether the patient is alive (and if so, what his condition is). As part of the typical rabies investigation, 15 healthcare workers and an unknown number of family members and friends have been deemed to have been potentially exposed to rabies from the man and have been offered post-exposure treatment. The risk of human-human transmission is exceedingly low, but given the severity of disease, the logical approach is to err well on the side of caution when considering post-exposure treatment.
While rabies strain typing supports a dog bite as the source, that can't be confirmed at this time since the man was too ill to provide any information by the time rabies was being investigated. Sometimes, exposure is determined indirectly based on information from friends and family (e.g. the person mentioning that he was bitten by a dog) and presumably there is an effort to question people who had contact with the man in the Dominican Republic to try to piece this story together.
A group of flea (or flea and tick) collars have been removed from the market in France following a risk assessment. The review looked at these widely available, over-the-counter products that contain a variety of different chemicals. The determination was that the risks posed by contact with the collars (particularly to children) were unacceptable compared to the benefits.
As with most risk assessments, cost-benefit is the key. With flea collars, you have something containing a chemical that's easily (and commonly) touched by people, and you also have the potential that young children could put them in their mouths. That's the "cost" aspect. The beneficial side is two-pronged. One consideration is the importance of flea and tick control to human and/or animal health. That's certainly significant, since fleas and ticks can be associated with various problems, including infectious diseases and flea allergies. However, the other consideration is whether there are safer and/or more effective alternatives. The answer to that is yes - there are now much better approaches for flea and tick control than flea collars in terms of effectiveness and safety. The disadvantage is that these alternatives are somewhat more expensive and not available over the counter, but the cost and logistics are far from cumbersome.
So, the withdrawal of the flea collars from the market in France is a very reasonable move, and one that needs to be accompanied by information to pet owners that emphasizes that:
- yes, flea and tick control are still important.
- there are much more effective options that are safer for the pet and the family.
- people should work with their veterinarian to determine the approach that best fits their pet(s) and family.
It's amazing how one little email comment can make a mess of my week.
Here's the story: I sent an email to a colleague that works for an agency in Ontario. At the bottom of the email, I gave an FYI about an Ontario dog that was found to have antibodies against canine flu, but that wasn't sick. At the time, I didn't realize that my colleague was no longer at the aforementioned agency.
- Astoundingly, instead of cancelling my colleague's email account, the agency had left the account active - and the CEO of the agency reads her emails!
- In this case, not only does the CEO read the email, she forwards it to other people in the agency.
- Not only do the others read it, they create a release that they send out to associates of their agency throughout the province and some other groups... without contacting me to get details, understand the full story or get permission to use the information I provided. Not exactly a good communications strategy.
In an amazingly short period of time, I was contacted by two provincial Ministries about Ontario's canine flu status, since incomplete information was forwarded to them, and veterinary clinics in the province are now asking questions about our "canine flu case" or "canine flu outbreak."
So, to set the record straight (and decrease the number of phone calls I'm getting today):
- We found a dog that had antibodies against canine influenza as part of an outbreak investigation. The outbreak was not caused by canine flu.
- The dog had the same antibody level on two blood samples taken two weeks apart. This is not consistent with disease caused by flu. Rather, it indicates that the dog has been exposed to the virus.
- The fact that the dog has been exposed to the virus is noteworthy. The only other seropositive (i.e. antibody positive) dog that we have seen in Ontario was a greyhound from Florida, and we assumed it was infected in Florida. That was a few years ago, and we haven't seen anything since. Initial information indicates that this dog has not left the province, but I'm working to confirm that before I can be confident that this is evidence that canine flu is present in Ontario.
This is an important topic because if/when canine flu hits a region, it certainly has the potential to cause big outbreaks. The outbreak at a Texas racing facility that I wrote about yesterday is a good example of the bad things that can happen when flu hits a susceptible population. Knowing if the virus is in the area is important for things like vaccination programs and making recommendations for management of respiratory disease cases in veterinary clinics and in the community.
We currently have no evidence of canine flu activity in Ontario, but we are actively looking because we assume that it will make it here sometime, if it's not here now. Identifying it early and communicating that properly are critical control measures for canine flu and other emerging infectious diseases, but there's nothing to worry about at the moment.
Don't tell Samuel L. Jackson (Snakes on a Plane was bad enough), but on August 2011, a bat was found flying through the cabin of a plane shortly after take-off from Wisconsin. Failing to heed the seat belt sign, it flew around the cabin a few times before it was eventually trapped in a bathroom. The aircraft then returned to the Wisconsin airport...vnot sure whether that was because they were worried about the bat or because they didn't have an available bathroom any more.
Unfortunately, when they got back to the airport, no one thought to close the plane door before opening the bathroom door, so the bat flew out of the bathroom, out of the plane, down the jetway, through the airport and was last seen exiting the airport via automatic doors (smart bat). The problem with the bat's escape is there was then no way to determine whether it was rabid, since even bats with a good sense of direction can be shedding the virus. Because of that, it had to be assumed that the bat was rabid and an investigation ensued.
The Wisconsin Department of Health called the CDC for assistance and a standard investigation was undertaken. A key component was to determine who, if anyone, was potentially exposed to rabies, assuming the bat was carrying the virus. Rabies is spread through direct contact of saliva from an infected animal with broken skin or mucous membranes (e.g. mouth, nose). Most often, this occurs via a bite. Being in the same area as a bat doesn't constitute a risk.
A rabies investigation typically involves interviewing people who were in the same area as the bat to see if they had any contact with it. That was done, but it was complicated by "difficulties obtaining an accurate passenger manifest...". (Considering it seems like I have to do everything short of depositing a DNA sample to fly to the US these days, I can't fathom how they couldn't have a list of who was on the plane.)
Anyway, the airline gave the CDC a list of 15 people that they knew were on the plane and 33 who had reservations (but apparently they didn't know for sure whether they were on the plane). Considering 50 passengers were on the plane (not counting the bat), that left a few unknowns, which was compounded by their finding that some people who had reservations confirmed they were not on the plane. They tried various ways to contact people, but ultimately ended up with 5 mystery passengers.
Fortunately, the risk of rabies exposure in this case is low. All 45 of the contacted passengers reported having no direct contact with the bat, and it's very unlikely anyone else did given the description of what happened. Similarly, none of the pilots (hopefully it was easy to figure out who they were) and other flight or ground crew reported any contact.
An environmental assessment was performed to see if there was a bat problem at the facility, and nothing out of the ordinary was found. They made a few recommendations to reduce the chance of this happening again:
- Use of netting to cover crevices in the airport where bats might roost.
- Extending and retracting jetways before the first flight of the morning (I guess to scare the bat out before a plane is hooked up).
- Training employees on bat capture methods.
- Testing any bats for rabies.
So, it was more of an interesting story than a true disease concern, but with rabies, you have to be thorough to convince yourself that there's no risk.
It also seems like this bat was much more organized than the airline.
As canine influenza continues it's rather gradual, patchwork movement across North America, an outbreak at a greyhound racetrack southeast of Houston highlights some of the concerns about this virus. Canine influenza has been active in the Houston region for some time, causing sporadic infections as well as outbreaks in pet dogs in the community and in veterinary clinics.
Greyhound tracks are a great place for influenza transmission because they have a lot of dogs in close quarters, and racetrack outbreaks can be large and severe. In this outbreak, approximately 100 dogs have been affected so far, with six deaths. It sounds like there are 600-700 dogs on the track, and given how transmissible the virus is, unless they have very tight infection control practices in place to separate groups of dogs (unlikely), it's reasonable to assume that many more dogs will be infected, or have already been infected but weren't recognized because they had mild disease. The ~6% mortality rate is not surprising, as dogs can die from severe influenza or because of bacterial pneumonia that develops afterwards. Higher death rates are talked about, and were features of the early reports of canine flu in Florida, but this lower rate seems to be more typical.
Local Humane Society personnel are rightly warning pet owners to be on the lookout for canine flu. Public awareness is critical, although I'd argue with some of their advice:
"The only protection is the dog flu vaccine."
- Not really. It's part of the infection prevention plan but not the only thing. Vaccination is an effective way to reduce the incidence or severity of disease, but it's not 100%. Vaccination should be considered the last line of defense that comes into play when efforts to avoid the virus have failed. If the dog doesn't get exposed to canine flu, it won't get influenza, regardless of vaccination status. Dog owners need to be aware of high-risk situations and avoid contact with dogs that are or have recently been sick. That being said, in an area where canine flu is active, vaccination is a good idea, since you can never completely guarantee your dog won't be exposed to the virus if it's exposed to other dogs.
"Dog owners were warned if they noticed any flu-like symptoms in their dog to take them to a vet immediately for antibiotics and the vaccine and not to take their dog to the park or doggie daycare."
- I agree with the last part. If your dog is sick, keep it away from areas where other dogs mingle while it's sick and for about 10 days after it gets better. So, if that's the case, why take all potentially sick animals into the vet right away? It might just result in exposure of other dogs to the virus. If you have influenza and you're not very sick or at high risk for complications, the recommendation isn't to immediately go to the doctor. It's to rest and stay away from other people. The same applies for dogs.
- Calling a veterinarian to see whether the dog should be examined makes sense. This also helps ensure that if the dog does go to the clinic, it can be handled properly. By that, I mean instead of showing up, checking in at the front desk and lingering in the waiting room with other dogs for a while, a dog with suspected flu should be admitted directly into isolation or an exam room. This can be done by calling the front desk on arrival or by checking in without the dog, so that the dog can be taken directly to a contained area to avoid other dogs.
- Antibiotics are rarely needed. Antibiotics don't kill influenza virus, so they are indicated only if there is evidence (or very high risk) of secondary bacterial disease, which doesn't happen in most cases. We don't want every coughing dog on antibiotics, since few need them.
A few months ago, I wrote about an article that appeared in the journal Orthopedics. It was a very bad article that blamed a person's infection on "excessive contact" with pets, with no evidence that the pets were involved (and no evidence that dogs have ever been found to carry the bacterium in question).
Here's the Letter to the Editor that was just published.
I was surprised to see the article “Pyogenic cervical spondylitis caused by Pasteurella haemolytica attributed to excessive contact with dogs” by Machino et al. 1 The authors stated that Pasteurella haemolytica (which was renamed Mannheimia haemolytica over a decade ago) is a common inhabitant of the oral cavities of dogs and cats, citing prevalence rates of 71% to 90% in cats and 21% to 60% in dogs. However, they provided no references for these prevalence data, and I am unaware of any studies that have found this bacterium in the oral cavities of dogs, let alone at such high rates. The authors cited 3 articles as supporting zoonotic infections with this organism, yet these 3 articles all involved other Pasteurella species. Pasteurella multocida, a completely different bacterium, is a common oral commensal in dogs and cats and has been reported frequently as a cause of pet-associated infection. The authors may have confused these markedly different organisms. The authors also stated that the recent increase in pet ownership has caused an increase in P haemolytica infections from bite wounds, with no evidence supporting an increase in infections caused by this bacterium or the role of pets in human P haemolytica infections. Although zoonotic infections are problematic and it is important to consider the potential role of household pets in human disease, this article is highly flawed, and retraction should be considered.
J. Scott Weese, DVM, DVSc, DipACVIM
Guelph, Ontario, Canada
The authors either didn't get any of the points I made or didn't care and wrote a rather evasive response.
We thank Dr Weese for his letter. We reported a rare case of Pasteurella haemolytica as the pathogenic bacteria behind pyogenic cervical spondylitis. We searched the literature for reports on spondylitis caused by P haemolytica to the greatest extent possible, but it seems that the present case was the first.
In the present case, a needle aspiration biopsy was performed under diskographic guidance, and P haemolytica was detected on bacterial culture. We believed that this case was caused by P haemolytica. Because the patient owns 2 dogs and frequently kisses them on the mouth, this excessive contact was believed to be the cause of infection. No other causes were evident in this case. Although we cannot declare that it is the cause, no evidence was found that it was not the cause.
Our main point in the article was that osteomyelitis has been reported in the field of orthopedics, and, keeping in mind the fact that pyogenic spondylitis is also caused by rare bacterium, we believe it is important to engage in routine treatment regimens.
Masaaki Machino, MD
Anyway, the point wasn't to make the authors look bad. It was to remind people that we need to consider pets as sources of infection but do so in a logical manner, and simply blaming the pet when there's no evidence doesn't do anyone any good.
As we've discussed previously, rabies has been a big problem in Bali since 2008. Previously rabies-free, this densely populated island has been struggling with a large and persistent canine rabies outbreak that has resulted in numerous deaths and much debate about control measures.
- Dog bites are very common on the island, with a daily average of nearly 100 bites reported over the study period. Since many bites don't get reported, even this large number is an underestimate.
- The average age of affected people was 36 years, with a range of 3-84 years. All 104 died.
- Most of the cases (57%) were male. This is common, although whether it is because men are more likely to be bitten (because of greater exposure or greater provocation) or less likely to seek medical care after a bite is not known.
- There was a history of a dog bite in 96/104 infected people. It's likely a bite occurred for the others as well, but in those cases the patient was unconscious at the time rabies was suspected and family members did not know of any bites.
- The incubation period ranged from 12 day to 2 years. It was less than 1 year in 98% of cases. Very short incubation periods, like the 12 day one reported here, are almost always associated with bites to the head or neck, since it's a shorter distance for the virus to travel up nerves to the brain.
- Early signs of disease are often vague. Pain or numbness at the location of the bite (37%), nausea or vomiting (30%), fever (22%), aches (17%), headache (16%) and insomnia (7%) were most common.
- 81% of people that developed rabies did not undergo any type of treatment. 11% washed the wound themselves. Only 6% went to the hospital on the day of the bite. The people who went to the hospital received a course of rabies vaccines but did not receive rabies immunoglobulin (RIG, which is anti-rabies antibodies). So, while they were treated, they didn't get the full recommended treatment. This is incredibly frustrating since rabies is almost 100% preventable if people get proper medical care. Failure of most of these cases to even seek care is a huge issue, and inadequate treatment of people who sought medical care compounds the problem. Not all of the vaccinated people completed the full vaccine course before developing signs of rabies. These were individuals who had short incubation periods because of bites to the head and neck.
These results are not surprising but demonstrate a few important concepts, including:
- the need for education of the general public to seek medical care after a bite.
- the need for proper education of healthcare providers so that people who are bitten get proper medical care.
- the need for adequate supplies of rabies vaccine and immunoglobulin. It wasn't stated whether people didn't receive RIG because it wasn't offered or (as is common in some regions) it wasn't available.
- rabies may not be considered initially when signs first start appearing, as many of these people ended up being treated for various other potential problems before rabies was considered. While rabies is almost always fatal, there have been very few "successfully" treated individuals (meaning they didn't die, but they can still have long-term neurological impairment), but to have any chance at success, treatment needs to be administered as quickly as possible.
- control of canine rabies is a key part of controlling human rabies.
Max, a 12-year-old Chihuahua from Greenfield, New Jersey, was euthanized recently after he was exposed to rabies. While far from unusual, the case highlights the ongoing risk of rabies exposure as well as issues with understanding of rabies guidelines and communication.
Max was attacked by a rabid raccoon - an ever-present risk for animals that go outside (or get outside) in many regions. Animal control was called and the raccoon was caught. It was euthanized and rabies was confirmed, indicating that Max was very likely exposed to the virus.
Here's where things seem to get strange. The paper reports:
"Once exposed to a rabid animal, a six-month quarantine is required for the exposed animal, even those animals that have been inoculated with a rabies vaccine."
- Not really. In Canada, standard guidelines are for a 6 month strict quarantine for dogs (and cats) that are not properly vaccinated, but only a 45 day observation period is required for vaccinated animals. I don't know if in this jurisdiction they made up their own different rules, whether someone doesn't know what's supposed to be done or whether it's poor reporting, but it's a concern because it can be a difference between life and death... not necessarily from rabies, but from the quarantine requirements alone. People are often unwilling to undertake a strict 6 month quarantine and choose euthanasia (as was the case here), while the 45 day observation period is much more acceptable.
The attending veterinarian stated "Because of the way it was exposed and because of the positive, I think there was a really good chance this dog was going to get rabies".
- It's certainly possible, and nowhere does it say whether Max was properly vaccinated. However, there's a reason we vaccinate. It's a highly effective vaccine and we're trying to prevent disease. Nothing's 100%, but with proper vaccination, the risk of rabies is greatly reduced.
It's also stated that "due to the nature of rabies, until behavioral changes occur, the animal is not infectious".
- While this doesn't have anything to do with Max's situation, it's not true. Animals can shed the virus for a short period before they show signs of illness. That's the reason there is supposed to be a 10 day quarantine period after a dog bites someone - to see if the dog develops signs of rabies (which would have major implications for the person who was bitten).
Curiously, the article ends with a reminder to vaccinate pets, which seems kind of strange if their assumptions are that an exposed animal will get sick irrespective of vaccination status and that vaccination will have no impact on what happens to an animal after exposure.
However, despite the miscommunication, the take-home message emphasizing the need for vaccination should be heeded. As well, people making decisions about what to do after rabies exposure should make sure they do so based on the best evidence that's available, namely the Compendium of Animal Rabies Prevention and Control.
.A five-month-old Britich baby was hospitalized with salmonellosis that was presumably acquired from a family pet. The baby developed severe diarrhea and was rushed to hospital. Fortunately, the child has recovered, something that's far from assured in such cases, since salmonellosis can be life-threatening in infants.
As expected, an investigation followed the diagnosis of salmonellosis. Typically, these investigations focus on food and animal contact, and since this family had a bearded dragon (see picture) and tortoises, the investigation honed in on the reptiles. Reptiles are high risk for Salmonella shedding and are commonly implicated in human infections. Further, the type of Salmonella that infected the infant, S. Pomona, is commonly associated with reptiles. It doesn't sound like they've confirmed that the same strain of Salmonella was present in the reptiles, but I assume that testing is underway.
Reptiles should not be present in households with infants. It doesn't matter if the animal never leaves its enclosure, because while the critter may not leave the enclosure, Salmonella will.
In low risk households (households without kids less than five years of age, elderly persons, pregnant women or immunocompromised individuals), good management practices can be used to minimize the risk of transmission of Salmonella, but given the potentially fatal nature of salmonellosis in infants and other high-risk individuals, these precautions are not adequate in high-risk households. While reptiles can be great pets, they're just not worth the risk in some situations.
The CDC has announced an investigation of three multistate outbreaks of salmonellosis linked to pet turtles. At last report, 66 affected people had been identified, and since most outbreaks like this only identify a minority of cases, it's safe to assume there are many others.
- Three different types of Salmonella have been implicated; S. Sandiego, S. Pomona and S. Poona.
- Infected people have been identified in 16 US states (see map).
- 11 people have been hospitalized, but no one has died.
- Most cases (55%) have involved children under the age of 10.
- Almost all infected individuals who provided information about turtle contact with said the turtles were less than 4 inches long.
This ongoing outbreak, dating back to September 2011, has all the hallmarks of a pet turtle-associated outbreak: a large number of cases over a wide area and prolonged period of time, a predilection for young children, and the potential for severe disease. While far from novel, this outbreak also highlights some recurring themes.
The potential for widespread outbreaks from mass production and distribution of pets has been repeatedly demonstrated with a range of diseases, including recent examples involving chicks and guinea pigs. That doesn't mean that mass production is necessarily higher risk (although it certainly can be), but when something goes wrong, it can go very wrong because of the large number of infectious animals that get sent out.
Sale of turtles with shell lengths under 4 inches has been banned in the US since 1975. This is because small turtles are more likely to be handled (and potentially put in the mouth) by young kids. Despite extensive lobbying by US turtle breeders, the law remains in effect, but it's widely flaunted. It's surprising more efforts aren't put into enforcing this regulation given the number of people who are sickened every year from contraband turtles. (It's also surprising that infected people in the US haven't started large lawsuits against people distributing small turtles.)
Anyway, this is yet another reminder about the risks associated with reptiles and high risk individuals (i.e. young children, elderly, pregnant, immunocompromised) and the need for pet turtle owners to follow basic hygiene and infection control practices. More information about turtles - for owners, veterinarians and healthcare professionals - can be found on the Worms & Germs Resources page.
Local media are reporting an apparent case of West Nile virus infection in a horse in Northampton County, Pennsylvania. This is surprising since, while I know there are certainly mosquitoes emerging early with this mild weather, seeing active mosquito-borne infections at this time of year would be very unusual. That's particularly the case with West Nile virus, since it tends to be a late summer and fall disease based on the mosquito types that are predominant at that time of the year.
Information about this West Nile virus case is pretty sparse. The report simply says the horse was euthanized because it was "suffering from the virus." Knowing if and how it was actually diagnosed is important to determine whether it was truly an active infection or a false-alarm, like this winter's report of West Nile virus in British Columbia.
Regardless, it's still a good reminder that we are now heading into the time of year when we have to think about mosquito-borne diseases in various species (including people). Measures to reduce mosquito populations, such as eliminating standing water (see picture), and mosquito bite avoidance are always good, regardless of what diseases are currently being diagnosed.
Image source: www.saskatoonhealthregion.ca
An outbreak of strangles (Streptococcus equi infection) has led to cancellation of the racing program at Saratoga Raceway in New York State. In a ripple effect, other racetracks in the region have taken measures to protect their horses, including banning horses from Saratoga, banning horses from surrounding tracks, not allowing horses that leave the grounds to come back and/or requiring that horses have a health certificate before entering the grounds.
As with most outbreaks, details are sketchy, including information about the number of exposed horses and specific outbreak response measures. Strangles is a highly infectious disease but it's also one that we know a lot about, and one for which containment of an outbreak is certainly possible with good infection control practices, screening to find carriers and a big dose of patience. Unfortunately, the latter is often the limiting factor, especially when money is on the line. The fact that Saratoga has initiated a quarantine and other tracks are taking precautionary measures is a good sign. Not long ago, most of these situations were met with silence and the hope that concealing the problem would make it go away (not usually an effective approach). We've come a long way in both our knowledge of strangles control and the industry's willingness to take control, so hopefully Saratoga (including officials and horsemen) is taking a good, evidence-based and patient approach to this outbreak.
Authorities in Hawaii are advising people in Oahu to eliminate standing water as a mosquito control measure. While it's always a good idea, it's of particular concern in this case bacause a rare type of mosquito, Aedes aegypti, was found around the Honolulu International Airport. This mosquito species is a highly effective vector for various infectious diseases, including dengue fever and yellow fever.
What does this have to do with companion animal disease? Well, nothing directly, but it's a good reminder of how infectious diseases can easily reach a distant area (even Hawaii) in a short period of time.
There are a plethora of mosquito-borne diseases out there, and presumably we don't even know about many of them. Mosquitoes don't fly very far, which helps contain these diseases to certain areas. However, mosquito-borne diseases can still spread over wide ranges if either the pathogen or the mosquitoes are hitch-hiking.
A common way for pathogens to travel is in various kinds of animals (especially birds) that can harbour the pathogen (usually a virus) and infect mosquitoes in distant areas.
Modern transportation can be an effective vehicle for pathogen-laden mosquitoes. Theoretically, all it takes is for a single infected mosquito to hop onto a plane and survive the flight to a new region. If the mosquito bites a susceptible host, it can cause a rare disease - that's of particular concern since it's unlikely that an exotic foreign disease in someone who has not left the country would be promptly diagnosed (and therefore promptly treated). Even worse, the disease could establish itself in the new region if a series of things happen:
- The mosquito has to bite something or someone.
- That something or someone has to be susceptible to the pathogen and that pathogen needs to grow inside the host's body to high enough levels that it can infect another mosquito.
- Another mosquito that can carry the pathogen must come along, bite the infected individual and acquire the pathogen.
- The new mosquito must then find another susceptible host to bite.
- The above needs to be repeated enough times that the pathogen establishes a foot hold in the area and starts causing disease.
Is this common? No.
Is it possible? Yes.
West Nile virus is an example of what can happen. This mosquito-borne virus came out of nowhere in North America in the early 2000's and caused widespread illness and death in humans, horses and various other species. Did it arrive via a mosquito on a plane? No one knows, but it's certainly a possibility.
At this time of year, I start to see ads from local feed supply stores about annual chick sales. Overall, it's not a big deal and most people that buy chicks don't have problems. However, it can be a particular concern for certain high risk groups, particularly young children, and outbreaks of salmonellosis are a recurring issue.
Contact with young poultry is considered very high risk for Salmonella exposure, since Salmonella shedding rates amongst the little guys are pretty high. Most outbreaks of salmonellosis disproportionately involve young kids, due to a combination of increased handling, poor hygiene and inherent increased susceptibility of young kids to infection. The problem is that sometimes people buy chicks because their young kids want to raise and handle them. Outbreaks associated with sales of young chicks, as well as hatching chicks in schools and daycare, have been reported.
A recent CDC report describes yet another multistate outbreak of Salmonella, this time associated with a mail-order hatchery.
The outbreak occurred from February to October 2011 and was first noticed through lab-based identification of clusters of Salmonella Altona and Salmonella Johannesburg. Ultimately, 68 cases of S. Altona and 28 of S. Johannesburg infection were identified in 24 states. Here are some highlights:
- 32% of people with S. Altona and 75% with S. Johannesburg were kids 5 years of age or younger.
- 74% of people with S. Altona and 71% of people with S. Johnannesburg reported recent contact with young poultry.
- Most people that had poultry contact reported purchasing chicks or ducklings at local agricultural feed stores. These stores got the chicks and ducklings from a single mail-order hatchery.
Mass production of animals for widespread distribution, whether it's guinea pigs like I wrote about the other day, or chicks and ducklings here, increases the risk of widespread outbreaks because a single focus of infection can have far-reaching effects.
Mass production and mail-ordering of chicks isn't likely to stop, so what can people do to reduce the risk?
- Keep high-risk people (that is kids 5 years of age or less, elderly individuals, pregnant women and people with compromised immune systems) away from young poultry. This includes keeping chicks out of schools, where hatching chicks is still performed in some areas.
- Use good hygiene practices when handling chicks or anything in their environment. Assume that all of the chicks are shedding Salmonella and treat them accordingly. By that I mean use good general hygiene practices, particularly hand hygiene, to reduce the risk of exposure.
- Stores selling chicks should also provide basic safety information to inform and remind people to use appropriate practices to reduce the risk of infection.
Botulism outbreaks in horses are usually bad news. Horses are very susceptible to botulism, and outbreaks in horses caused by contamination of food often end up killing multiple horses on a farm. The recent botulism outbreak in Reddington, IN is another reminder of how deadly it can be.
The outbreak involved a family that lost five horses to suspected botulism. "Suspected" because this disease can be hard to confirm sometimes, although it's usually possible to make a pretty solid presumptive diagnosis based on how the horses look and by ruling out the few other possible causes. The details are pretty sketchy. Apparently there are some other sick horses, but how sick they are and how many isn't clear.
Botulism occurs in two ways. In adult horses, it almost invariable occurs after ingestion of the extremely potent botulinum toxin produced by the Clostridium botulinum bacterium. In foals, it usually occurs after ingestion of the bacterium, which then produces toxin in the foal's intestinal tract.
In adults, outbreaks are usually associated with contaminated feed. There are some high-risk feeds like haylage and silage (see photo) that we usually focus on first, but sometimes botulism toxin can be found in hay or other common feeds. Haylage, silage and other fermented feeds become a problem with they are improperly fermented, allowing the Clostridium botulinum to grow and produce its toxins. Sometimes, contamination of feeds can occur when an animal that has died of botulism (and has the bacterium and its toxins in its body) gets incorporated into hay or other feedstuffs.
When an outbreak is suspected, a key step is removing any potentially contaminated feeds to reduce further exposure, although often it's too late by the time the disease is recognized. Antitoxin (which is pre-formed antibodies that help neutralize the botulinum toxin) can be given to exposed horses, but it's extremely expensive and does not reverse any damage that's already been done. That's why these outbreaks are often so disasterous, because when the diagnosis is made the only thing left to do may be damage control to try to save some of the less affected horses. That's tough because botulism has a very high mortality rate in horses.
The farm owners in Reddington are urging local horse owners to be on the lookout for botulism. It's reasonable, but rarely do we see multi-farm outbreaks from botulism. They also state that botulism doesn't affect cattle, which is wrong. Cattle are more resistant than horses, but they certainly can get botulism.
A botulism outbreak in horses poses little risk to people. People are susceptible to this horrible disease as well, but to get it someone would have to ingest the same contaminated feed that the horse did. There's no risk of transmission of botulism from an infected horse to a person or another animal.
We've had a really bizarre spring around here. At a time of year when we're usually bouncing back and forth between snow and rain, we seem to have skipped over spring and moved right into summer. It was 25 C (77F) today, the snow's long gone, frogs are deafening at night and, on the bad side, mosquitoes are swarming at dusk.
This has led to a lot of questions about the implications of the weather on the regional approach to heartworm prevention, since the typical approach is to start treatment in early June. Specifically, does the early spring mean that there's increased risk from this mosquito-borne parasite or that we need to start treating dogs earlier?
Dr. Andrew Peregrine, a veterinary parasitologist at the University of Guelph, has taken a break from fielding calls about this subject to provide some insight.
A big question is whether over-wintering infectious mosquitoes are a concern.
If over-wintering mosquitoes aren't a concern, which is a leading consensus, then the mosquitoes we're seeing now are newly hatched.
- If that's the case, they have to feed on an infected animal and the parasite has to mature inside the mosquito before the mosquito poses a threat to dogs (and less commonly cats, and very rare humans).
- With the current temperatures, it should take at least three weeks for this to happen. Therefore, if a mosquito hatches in March and happens to feed on an infected animal, it would be into April before it's infectious. Heartworm preventive medication has 'reach-back' activity of at least 7-8 weeks, meaning that the medication will effectively prevent disease from exposure at least 7-8 weeks prior to treatment.
- So, if a mosquito promptly feeds on and infects a dog after it becomes infectious, heartworm medication given at the beginning of June would still be effective at preventing disease because of this reach-back period.
- In this scenario, there's no need to start treatment any earlier around here than the traditional June 1 start date.
There are some people who think that overwintering infectious mosquitoes are an issue, although evidence supporting that seems to be lacking. If overwintering infected mosquitoes are an issue, the mosquitoes that are around now might be infectious.
- In that case, June 1 might be too late in the event of an early exposure, and May 1 would be a more appropriate start.
Bottom line, there is no answer that's 100% certain since we don't have all the information that we need. June 1 is most likely perfectly fine. Anyone who's's ultra-concerned could start treatment on May 1. There's no real downside (apart from a little extra cost) of this extra treatment, but it's probably not necessary.
Guinea pigs are relatively benign pets in terms of zoonotic diseases, but like any animal, they can carry some pathogens that are transmissible to people. This was highlighted in a poster presentation at the recent International Conference on Emerging Infectious Diseases in Atlanta. The poster (Bartholomew et al) described a CDC investigation into an outbreak of Salmonella Enteritidis infections in people in multiple states in 2010.
Here are some highlights:
- The first affected person was a child who purchased a guinea pig from a pet store. The animal looked "frail" and was housed with the child's existing guinea pig. Later that month, both guinea pigs developed diarrhea and died. Shortly thereafter, the child developed diarrhea, fever, cough, chest and back pain, a rash and some other signs. Ultimately, a Salmonella infection of the sternum was diagnosed, indicating that Salmonella had traveled from the intestinal tract to the child's bloodstream and set up an infection in the breast bone.
- The CDC investigation focused on other people who had been diagnosed with the same strain of S. Enteritidis. They identified 10 such cases who also reported guinea pig exposure, scattered over 8 US states.
- The same Salmonella strain was also identified in guinea pigs, including one from a Texas guinea pig broker, around the same time as these cases were occurring.
- Most of the affected individuals were children. Three had purchased guinea pigs from the same pet store chain as the first child. Three other affected people were employees of stores from that pet store chain.
- Testing of the environment in pet stores from that chain did not identify Salmonella. However, since sampling was done well after people got infected, it doesn't mean it wasn't there earlier.
- No common guinea pig source supplier was found, but one Pennsylvania breeder was identified as a possible source for the cases associated with that pet store chain.
This is pretty strong evidence that the infections were guinea pig-associated.
Some take-home messages:
- Any animal can be a source of potential infection, and general hygiene practices should be used all the time to reduce exposure to pet feces.
- Sick animals might mean the potential for sick people. While it's sometimes tough to convince people that testing dead animals (especially dead animals that don't cost much) is useful, it might have had a great impact on the care of the first child. If physicians knew that the child was exposed to Salmonella, they might have been able to make the diagnosis much quicker.
- Pet stores are not uncommonly implicated as sources of outbreaks, and there are also risks to their staff. Pet stores need to have good infection control, hygiene and disease reporting practices.
- The nature of pet rodent distribution, with large breeders sending animals to brokers where large numbers of animals get mixed and sent on to pet stores, creates the potential for widespread disease transmission, as has been repeatedly shown in the past.
The Ontario Ministry of Natural Resources and Welland SPCA are warning people about an apparently large number of cases of distemper in raccoons in the area. Distemper is a pretty nasty disease which can be spread between dogs and wildlife. It’s caused by canine distemper virus, but the "canine" part of the name can be a little misleading, since this virus readily infects some other species such as raccoons.
In addition to the problems with sick and dying raccoons caused by the outbreak, there are two main concerns for pet dogs:
One concern is the potential for wildlife to transmit canine distemper virus back to dogs. It’s hard to say what the risk of that is, and the risk would be primarily to young dogs that are not adequately vaccinated. If a dog has an encounter with a raccoon that is sick with distemper, it’s possible the pet could be exposed to the virus. Dogs are also probably more likely to have close encounters with sick raccoons that are unable or unwilling to run away, as opposed to healthy raccoons. If an inadequately vaccinated dog gets exposed, it can get very sick, which is obviously bad for the dog, and also creates another potentially infectious animal to keep passing the virus along.
The other concern is differentiating distemper from rabies. Distemper can cause signs that are very similar to rabies. If a dog has an encounter with a raccoon that is behaving abnormally, rabies is a big concern. If a dog is exposed and the raccoon is not available for rabies testing, the dog would require a 6-month strict quarantine or euthanasia if it's not vaccinated (or not adequately vaccinated), or a 45 day "observation period" (on a proverbial tight leash) if vaccinated. These measures aren’t easy to implement, and unvaccinated dogs often end up being euthanized because owners don’t want to go through the hassle of a 6 month quarantine.
What does this mean to the average pet owner? Well, nothing that they shouldn’t be thinking about anyway. This just increases the relevance of some routine measures such as:
- Keeping dogs that are outside are under control so they don’t encounter wildlife.
- Ensuring dogs are properly vaccinated against distemper and rabies.
- Taking particular care to prevent exposure of young unvaccinated dogs to wildlife.
- Discouraging raccoons from taking up residence in yards.
Nothing earth-shattering, but these basic precautions can greatly reduce the risk of disease transmission from wildlife to dogs, be it rabies, distemper or other bad bugs.
An interesting and frankly somewhat scary report in an upcoming issue of Veterinary Microbiology (Clegg et al 2012) provides further information suggesting that cats might be a source of canine parvovirus infection. This potentially fatal infection, which typically affects young unvaccinated (or inadequately vaccinated) puppies, is a major problem, and outbreaks occur (not uncommonly) in some high-risk populations like shelters.
In the 1970s, a new form of canine parvovirus, CPV-2, emerged and rapidly spread worldwide. That predates my veterinary career but I've heard stories of clinics where you couldn't turn a corner without stepping on a dog that was hospitalized for treatment of parvo, since it was a new disease and vaccines were not yet available. CPV-2 was shown to be able to grow in cat cells in the lab, but not in live cats, so it was generally assumed that dogs had CPV and cats had their own closely related virus, feline panleukopenia virus (FPLV). However, new variants of CPV-2 have emerged over time, and these seem to have a greater ability to infect cat cells in the lab, and disease caused by these strains has been reported in cats both experimentally and in limited real-world situations. However, it was still considered an uncommon event and the role of cats in parvovirus infection of dogs was largely thought to be inconsequential.
Or maybe not.
In this new study, researchers collected fecal samples from 50 cats in a cat-only shelter, and 180 samples from 74 cats at a shelter than housed both dogs and cats. Canine parvovirus shedding was identified in 33% of cats from the cat shelter and 34% of samples from the dog/cat shelter. A concern with a study like this is cross-reaction of tests for CPV and FPLV, but they went a few steps further to confirm that the virus was indeed CPV, not its feline relative. They also showed they could grow the CPV from fecal samples in cells in the lab, which means they were detecting live virus in the animals, not just dead viral bits working their way through the cats' intestinal tracts.
The results are interesting and concerning, since they showed that a pretty large percentage of cats in some situations could be shedding live CPV, making them a potential source of infection for dogs (and possibly other cats).
What makes this even more concerning is the duration of shedding that they identified when they collected samples from the dog/cat shelter over time: cats shed the virus for up to 6 weeks, despite appearing healthy.
This raises concerns about the potential role of cats in the spread of CPV. Cats and dogs don't tend to mix much in parks or outside, but CPV is a very tough virus that can survive for a long period of time in the environment. It's certainly plausible that cats could be depositing CPV-laden feces in the outdoor environment, and since the virus can survive the outdoor exposure and some dogs are notorious poop-eaters, it's a route of transmission that can't be dismissed. Cross-contamination within shelters is also a concern.
The true role of cats in canine parvovirus infection isn't known and it's probably quite limited compared to dog-to-dog spread. However, this study shows that we at least need to be thinking about it and considering cats when dealing with parvovirus problems in shelters and households.
Some things to think about:
- Young puppies should be kept away from cats, especially strays and cats from shelters, until they are properly vaccinated.
- Parvo is one more reason to have good physical and procedural separation between cats and dogs in shelters.
- If a parvo outbreak in underway in a facility, prevention of potential cross-contamination from cats is required.
- If a cat has been in contact with a dog with parvo, it should probably be considered potentially infectious and kept away from susceptible dogs for at least a few weeks.
- Canine parvovirus vaccination is highly effective in dogs. If a dog is properly vaccinated, the risk from cats (or other dogs for that matter) is minimal.
While rare, Morocco continues to be a source of rabies in European animals. The latest case involved a puppy imported into the Netherlands. The (somewhat) brief version of what happened goes like this:
- On Jan 28, 2012, a Dutch couple bought an 8-week-old puppy in a parking lot in Morocco. The puppy was taken to a local veterinarian, microchipped and given a certificate of good health. It would have been too young to vaccinate against rabies.
- On Feb 4, the couple travelled from Morocco to Spain by car and ferry. They then obtained a European pet passport from a Spanish vet, despite the fact that the dog was not vaccinated against rabies (an EU requirement for a pet passport).
- On Feb 11, they returned to the Netherlands. Customs officials "cuddled" with the puppy but apparently didn't ask about rabies vaccination. When they got home, the couple exposed the puppy to many family and friends.
- On Feb 14, the puppy started to become aggressive. They contacted a veterinary practice, and it was assumed the problem was stress, so a sedative was given. (It's not clear whether the puppy was actually examined. If not, that's a pretty big mistake.)
- On Feb 15, the puppy was uncontrollable. The report states "When they realized that the puppy originated from Morocco, the veterinarians contacted the Netherlands Food and Consumer Product Safety Authority (NVWA)." The puppy's history should have been a basic question asked when the couple first contacted the veterinary practice about the animal. Regardless, the concern about rabies came to the forefront with that information, and the puppy was euthanized. Rabies was confirmed that evening (a pretty impressive turnaround time for rabies testing).
- As is typical, an investigation was launched, and a search for people who had contact with the puppy during the period when it was potentially infectious was started. That's not easy when it involves multiple countries, as was the case here, since the potentially infectious period is 10-14 days prior to the onset of clinical abnormalities. The potential contacts included the Moroccan veterinarian, some friends in Spain, the Spanish veterinarian, three customs officials, a couple of unknown people in a Spanish restaurant and at the Malaga airport, and 43 people after arrival in the Netherlands (plus an unknown number of people who petted the puppy on the street).
- Contact doesn't mean exposure, since rabies isn't transmitted by casual contact, so the type of contact was queried further. The risk is from bites or contact between the dog's saliva and broken skin or mucous membranes (e.g. mouth, eyes). Because of concerns that kids don't accurately recall the type of contact they have (meaning they might fail to mention a little nip or some other high risk contact), all nine children who had contact with the puppy were given post-exposure prophylaxis. The Dutch friends in Spain reported high risk exposure and were also treated, however they had to return to Amsterdam for full treatment since anti-rabies immunoglobulin (antibody) was not available in Spain. Information was provided to Moroccan officials but information about what happened there wasn't available.
- Overall, it is stated that 45 people needed post-exposure treatment (although who those 45 were isn't really clear). That's a pretty large exposure, resulting is much angst and expense.
- Two cats and a dog were also exposed to the puppy. The dog had been vaccinated, and received a booster. (It would also be standard protocol to quarantine them for 45 days as well, but that's not stated.) The cats were euthanized because a "suitable quarantine place was not available," a rather strange statement since quarantine isn't a very high tech procedure.
Obviously, this is of relevance to people that live in Morocco or are going to get a dog from Morocco. Those people need to be aware of rabies, be careful when getting a pet, ensure their pets are properly vaccinated against rabies and be careful around stray animals. This report also highlights a couple of other issues:
- A parking lot isn't a good place to buy a puppy, for many reasons. A reputable breeder isn't going to sell a puppy there, and there are lots of good, well-evaluated puppies available through good breeders and shelters.
- Pet importation requirements are pretty weak in a lot of ways, especially if no one actually pays attention to them. That seems to be a recurring theme as well with these imported rabies cases. Here, the puppy was given a European dog passport without the required rabies vaccination, and was not kept in quarantine after arrival. It also went through no less than three customs points in transit, where no one queried rabies vaccination status. The mandatory 3 month quarantine would have prevented exposure of most of the people that required post-exposure treatment.
- Visitors to areas where rabies is endemic in the dog population need to be aware of it. Encountering stray dogs isn't exactly rare in many countries, and while staying away from strays is a good general rule everywhere, people should be particularly careful in areas where the risk of rabies is high. Travelers also need to be aware of what to do if they are bitten by a stray animal.
In response to the large and high-profile equine herpesvirus outbreak that occurred last summer, the California Department of Food and Agriculture has published a Biosecurity Toolkit for Equine Events. It's a nice, comprehensive document that goes over a wide range of things that can be done to reduce the risk of disease transmission at horse shows and similar events, and is one of the better resources available on the subject.
As I've said before, I don't use the term "biosecurity" for equine events since I think it's a fallacy. Biosecurity involves keeping infectious agents away from a group of animals. You can do that on a chicken farm, where you bring in a bunch of chicks at the same time, house them under tightly controlled conditions, keep people away, don't let them near any other birds, send them to slaughter all at once, and then disinfect the place before starting again. With horse events, we create absolutely beautiful conditions for infectious diseases to be introduced and transmitted. For example:
- Many horses from many different areas with different health statuses are mixed together.
- Vaccination requirements are often sparse to non-existent.
- Horses have a high likelihood of direct and indirect contact with each other.
- Healthy horses can carry a variety of infectious agents.
- People often bring horses that they know are or have recently been sick, and there's little scrutiny of arrivals to detect any infectious horses.
So, for me, we instead deal with infection control when horses are involved, whereby we try to reduce (but know we can never eliminate) the risk of infectious diseases and outbreaks.
Is it just a matter of semantics? To a degree, yes, and maybe it's just the Professor side of me coming out. At the same time, I think it's important to consider the difference since we have to acknowledge the inherent risks that come with showing horses, think about the risks involved with different situations and come up with practical ways to reduce those risks as much as possible.
Good infection control practices for equine events, with measures taken by both organizers and attendees, are a good start.
Photo credit: John Goetzinger (click for source)
Kennel cough, also (and more properly) referred to as canine infectious respiratory disease complex (CIRDC), has been in the news lately. This condition is a syndrome, not a specific disease, being potentially caused by a range of bacteria, viruses and Mycoplasma, including canine parainfluenza virus, canine influenza virus, canine respiratory herpesvirus, canine adenovirus, distemper virus, Bordetella bronchiseptica and Streptococcus zooepidemicus. Regardless of the cause, it's still a highly infectious disease characterized by a hacking cough. Serious illness, including deaths, can occur but is uncommon.
Here are a couple of kennel cough issues have hit the press lately:
- Mandatory kennel cough vaccination is now required for dogs competing in the Iditarod Trail Sled Dog Race. It's easy to see how this disease is a concern in these sled dogs, given the stress and rigours of competing and the mixing of many dogs from different areas. Kennel cough vaccination doesn't prevent all cases, since it only protects against Bordetella bronchiseptica +/- parainfluenza virus, but it's a useful infection control tool in high risk populations. The requirement has been implemented in part due to cases of kennel cough that were encountered in the 2011 race, along with the publicity that was generated (including the attention of PETA).
- In Rocklin, California, a dog park was closed for two days because of a kennel cough outbreak. It seems the closure was in response to the diagnosis of kennel cough in two dogs, and it's an unusual move given the apparently low number of cases. The issue isn't the park environment itself being biohazardous - rather, the park provides an opportunity for dog-dog transmission. Given that, it's a questionable control measures since it's unlikely that people will keep their dogs at home. Rather, they'll probably just go to another park, where the same risks will be present. It's a bit like the debate around school closures with pandemic influenza. On the surface, it seems like a good idea, since kids won't pass around flu at school. However, in reality, what happens is kids congregate at the mall and other places if schools are closed, so it just moves the site of transmission somewhere else and probably doesn't have any net benefit. Here, a better response would probably be an educational campaign to get people to keep sick dogs at home, have people keep their dog away from other dogs at the park and encourage vaccination of high risk dogs (which would include those that go to a park and interact with other dogs).
- A kennel cough outbreak was reported in Bozeman, Montana, with veterinarians asking owners to be on the lookout for disease. Local veterinarians reported a spike in the number of cases, with one clinic reporting around 20 cases in the past month, which is a pretty remarkable number for your average vet clinic.
- And locally... nothing specific, but I keep getting reports of clusters of respiratory disease in dogs. We often don't get a chance to investigate small clusters to figure out the cause, since information often gets to me after the fact, but it's a recurrent problem in Ontario. Most of the reports are rather poorly defined clusters of sick dogs, with occasional severe outbreaks involving fatalities (including one I'm dealing with at the moment).
The parents of a US soldier who died of rabies after being bitten by a dog while deployed in Afghanistan want their son's superiors to be held accountable. Specialist Kevin Shumaker died last August, eight months after being bitten by a dog. An Army investigation concluded that he died because members of his unit ignored rules prohibiting keeping pets (they were befriending feral dogs) and that he didn't seek treatment or notify the chain of command after being bitten. His parents feel that their son is being falsely blamed and that people who should have known better didn't do their jobs. It's a complex issue with some interesting questions.
What should the average soldier know about rabies?
It should be assumed they know absolutely nothing to start off, and a risk assessment should be performed for each deployment to determine what they need to know. When they are being deployed to a rabies-endemic area, they need to learn to stay away from dogs and report dog bites promptly, and why.
Whose job is it to report a bite?
At the end of the day, everyone has to be their own advocate and make sure they report any possible rabies exposure. People up the chain of command don't see everything and individuals need to protect themselves. However, once the bite is reported, others have to act. That might be the breakdown here.
Was anyone actually notified?
The Army's investigation actually documents the fact that Spc. Shumaker notified other personnel at least twice. One was a veterinary corps officer and the other was the person doing his post-deployment health screening. Here's where the ball was probably dropped. Every veterinarian knows about rabies. A veterinarian working in a rabies endemic region is certainly aware of the risks and has a responsibility to act on a reported bite. I find it astounding that a veterinarian in this situation wouldn't initiate a response, particularly given the fact that (at least in my limited experience) the US Army Veterinary Corps has some excellent veterinarians, so this seems rather strange. Further, what's the purpose of a post-deployment health screening if health issues that arise are ignored? If the person doing the health screening didn't understand the concerns about rabies, he or she was inadequately trained and shouldn't have been doing the job. If the screener was properly trained and didn't report it, he or she was incompetent, plain and simple.
Would anything have changed the outcome here?
Absolutely. Rabies is almost 100% fatal, but it's almost 100% preventable when post-exposure treatment is given before the onset of disease. There was lots of time in this case between the bite and when the soldier became ill, and if he had been treated following one of these reports, you can almost guarantee he would not have developed rabies.
Whose fault is this?
Well, everyone plays a role here. The soldier ignored the animal contact rules. Superior officers on base presumably ignored the fact that they were ignoring the rules, probably not thinking about the possibility of rabies, and seeing the positive effect on morale of interacting with the dogs. If the veterinary officer and post-deployment health screener were told about the bite and did nothing, they played a huge role since they, of all the people in this chain, should have known better.
What should happen here?
Rather than fighting over who's to blame (the usual response), an investigation should figure out why this happened and how to prevent it from happening again, largely via better training and clear expectations of personnel.
Hopefully that's happening, since Deputy Commanding General Maj. Gen. William Rapp recently approved a series of recommendations, including:
• Further investigation to see if any members of the unit should be disciplined for their actions or omissions during the unit’s deployment to Afghanistan
• Institute an animal-borne disease surveillance program, standardize rabies vaccine requirements and improve dog bite reporting requirements (I'm surprised that wasn't already the case)
• Reinforce animal bite and rabies training for veterinarians and post-deployment health screening staff
Rabies is pretty rare in horses in North America, with only 37 reported cases in the US in 2010 and 1 in Canada in 2011 (the latest years for which data are available). So, finding two apparently unrelated cases of rabies in horses in the same area in the same month is pretty unusual and concerning. Yet, that's what's happened in Tennessee, where rabid horses were identified in both Rutherford and Marshall counties in January.
Little information is available about the cases, but both were identified as having the skunk rabies virus variant. That doesn't necessarily mean they were infected by skunks (since other species can be infected by this virus variant) but it is suggestive, and indicates that rabies must be active in the skunk population in that region.
Regardless of the source, these cases are a reminder of why rabies vaccination of horses is important, and why rabies vaccination is considered a "core" equine vaccine by the American Association of Equine Practitioners. Rabies is invariably fatal in horses and it's also a major public health risk. While I've been unable to find confirmed cases of horse-to-human rabies transmission, it's a possibility, and additionally, rabid horses have killed people because of their unpredictable and aggressive behaviour.
Vaccination is cheap insurance against rabies - it's never a 100% guarantee, but it's a whole lot better than without vaccination.
There's been a lot of publicity (aka hype bordering on paranoia, including a recent article in the Toronto Star) about the cat-associated parasite Toxoplasma gondii lately. Cats are the definitive host of this parasite and it can cause serious disease in certain people: in pregnant women who have not been previously exposed to the parasite it can infect the unborn fetus, and it can cause severe illness (including neurological disease) in people with severely compromised immune systems. It's also been very loosely implicated in various other conditions, but much of the information gets overblown, as there is lack of solid evidence of a role of Toxoplasma in most of these cases. Unfortunately, cats end up getting a bum rap in the process, even though most Toxoplasma infections don't come directly from cats.
Nonetheless, toxoplasmosis is a potentially devastating disease in some circumstances. and taking measures to reduce exposure to the parasite makes sense. To do this you need to know what makes cats more likely to be infected, so that these factors can be modified. A recent paper in Preventive Veterinary Medicine (Opsteegh et al. 2012) investigated risk factors for cats having antibodies against Toxoplasma. It's important to note that the presence of antibodies means the cat was exposed at some point and mounted an immune response, not that it's currently shedding the parasite in its feces. Most cats only shed Toxoplasma in their feces for a very short window of time (a week or two) after initial exposure, and that usually occurs early in life. Therefore, it's rare for older cats in households to be shedding the parasite.
The research group found 18% of cats they tested had antibodies against Toxoplasma, and they identified a few factors associated with previous Toxoplasma infection:
- Age: Younger cats were less likely to have antibodies. The likelihood of having Toxoplasma antibodies increased steadily from 1-4 years of age.
- Presence of a dog in the house
- Being a former stray
- Feeding raw meat
Most of these make perfect sense and are consistent with other studies. Cats typically get infected by ingesting Toxoplasma cysts found in the muscle of other animals. So, cats that are outside (indoor/outdoor cats, former strays) and hunt, or cats that are fed raw meat are more likely to be exposed. Analysis of the data indicated that hunting contributed the most.
So, while the risk of Toxoplasma infection for the average person is pretty low, some basic management practices can further reduce any risk:
- Keep cats indoors: This greatly reduces the chance they will be exposed to the parasite. It is also good idea for several other reasons.
- Don't feed cats raw meat: Cooking meat to the recommended temperature and time will kill any encysted parasites - this also helps prevent exposure of people eating the meat (to Toxoplasma and lots of other bacteria).
- Control rodents in the house (not by getting a cat!): Indoor cats can still be exposed to various infectious agents through catching mice. I know it's not always easy or even possible (my cat still catches the odd indoor critter) but taking measures to reduce the likelihood of this is wise.
Other important preventive measures include:
- Changing the litterbox regularly, especially if a high-risk person has to do it. Toxoplasma oocysts need at least 24-48h in the environment to become infective. If feces are removed daily, they don't get that chance.
- Clean up any fecal accidents and remove any fecal staining of the haircoat (e.g. poop stuck around the rear end of long-haired cats) promptly, before that 24-48h window expires.
- Wash you hands regularly, especially after contact with the litterbox or any potentially contaminated areas.
- Wash vegetables and cook meat properly. You're more likely to get Toxoplasma from food than from your cat.
More information about Toxoplasma can be found on the Worms & Germs Resources page.
TheHorse.com has reported on an outbreak of Rhodococcus equi that has claimed the lives of seven ponies at an equestrian facility on the island on Mayotte (a French protectorate off the coast of Madagascar). Local agriculture officials report that two other horses are also affected, but recovering, and the facility has been quarantined
There are a few strange aspects of this report. Rhodococcus equi is an important cause of respiratory disease in foals, in which it can cause serious abscesses in the lungs. However, it's extremely rare in mature horses, and it seems that the horses affected in Mayotte were adults. It's not impossible, but an outbreak of Rhodococcus in adults would be incredibly surprising, indicating either something that made these horses remarkably susceptible to the bacterium, or the presence of a strain of Rhodococcus more able to cause disease in adults. A more likely explanation is that it's not actually Rhodococcus. There's no mention of what type of disease the horses had or for what other infectious agents tests were done. A Department of Agriculture official stated that the diagnosis was made by blood tests, but blood testing is pretty useless for diagnosis of Rhodococcus. So, I'd consider the diagnosis highly questionable without further information.
Whatever the cause, something that kills seven horses on a farm is remarkable and thorough testing is needed to determine exactly what's happening. In the unlikely event that this was caused by Rhodococcus, more work needs to be done to explain why the outbreak occurred and why it was so severe. If (as is likely) it wasn't Rodococcus, knowing the actual cause is important for controlling further spread and preventing problems in the future.
Fortunately, the remote nature of this location makes it rather unlikely that whatever's happening there will spread to another region soon.
Image: Location of Mayotte (click image for source)
Equine Guelph has announced a series of equine biosecurity workshops across Ontario which will take place during the month of March 2012. The sessions are free to attend and will focus on how to apply basic and practical concepts of infection control to reduce the risk of disease exposure and outbreaks in horses of all types. The workshops are part of a broader Beat the Bugs biosecurity program being organized by Equine Guelph, which also includes a two-week e-session being offered in April 2012.
More information about the workshops (including dates and locations, and to register), e-session and the Beat the Bugs program can be found on the Equine Guelph website.
An article from NBCMontana.com describes a kennel cough outbreak in dogs in Bozeman, Montana. It's a pretty basic article that outlines a rather typical presentation of kennel cough (now largely referred to as canine infectious respiratory disease complex - a respiratory infection that can be caused by a range of viruses, bacteria and Mycoplasma).
As part of the story, they state that if you have a sick dog, the "best course of action is to call your local veterinarian and get medication." I realize it's a quick statement, perhaps tossed in without much consideration, but there are some important issues to consider.
Should someone call a veterinarian and get medication, or should a veterinarian actually see the dog?
- Sometimes dogs just need to be given time and rest. Viruses are often the cause of this condition, and it just takes time for the infection to resolve (just like person with a cold virus). If that's the case, a little over-the-phone veterinary advice might be fine. If drugs are needed, then the dog needs to go to a veterinarian. Affected dogs might need something to control cough, which need to be given by prescription, and occasionally antibiotics are needed, but in either case a veterinarian needs to see the dog first. If the dog is sick enough that it needs additional treatment above and beyond this, then of course it needs to be seen by a veterinarian.
Are there any problems with a dog like this going to the veterinarian?
- Here's where the ball often gets dropped. The last thing we want to see is someone walking through the from door with a hacking, biohazardous dog who goes nose-to-nose with other dogs in the waiting room, breathes on half of the surfaces in the room, sits there for ten minutes while waiting for the appointment, and gets handled by every staff member before they realize the dog might be infectious. A situation like that can turn a veterinary clinic into a source of infection for many other dogs, and help an outbreak spread.
A very basic but well coordinated approach can greatly reduce the risk of dogs infecting other dogs in the clinic. These would include:
- Not taking a biohazardous dog into the waiting room. The owner can call from the car upon arrival or come in without the dog to let the clinic know they're there.
- The dog can be admitted directly into isolation or an exam room, thereby avoiding contact with other animals in the waiting room or elsewhere in the clinic.
- Veterinarians and techs that are going to work with the dog can know in advance and come in prepared, wearing appropriate protective outerwear (e.g. gloves and a labcoat or gown that they use for only that appointment) to prevent contamination of their clothing or body.
Very easy to do. Probably very effective too, but often not done.
Rat bite fever is an infection caused by the bacterium Streptobacillus moniliformis (the main cause in most countries) or Spirillum minus (the main cause in Asia). The condition is, not surprisingly, associated with being bitten by a rat, although it can be transmitted by other routes such as dog bites. The bacteria live in the mouths of most rats (and a less-well-understood percentage of other animals). Disease occurs when these bacteria make it into the body via a bite, or other high-risk contact such as kissing the animal or letting it lick an open wound.
The Australian case report describes a 26-year-old woman who had a fever and sore throat, which progressed to a severe unrelenting headache with nausea, vomiting, sensitivity to light, neck stiffness and pneumonia. Streptobacillus moniliformis was isolated from a blood sample. The strain was fortunately susceptible to the antibiotics that had been started earlier. It wasn't until a couple of days later that a rash (a classic sign of rat bite fever) developed. Fortunately at that point the diagnosis had already been made and the woman was responding to treatment.
After "further history taking" it was revealed that the patient owned two rats and, while she had not been bitten, she had close contact with them, including kissing. It's not clear when the "further history taking" occurred, but it probably happened after they found the S. moniliformis and made diagnosis, which rounds out the case report nicely but doesn't speed up the diagnosis or improve case care. The animal contact question needs to be asked at the start. One of the Lessons from Practice that the article highlights is "A thorough history, including history of animal exposure and pet ownership, should be taken for all febrile patients." Remove "febrile" and I agree completely.
Anyway, the woman responded to treatment and went home after 17 days in hospital. Most people that are properly diagnosed and treated survive, but rat bite fever can be fatal.
Most rats carry at least one of the two bacteria that cause this disease. There's no indication to test pet rats (since we assume they all have the bug until proven otherwise, and we can't confidently prove otherwise) or treat them (since we have no evidence we can eliminate the bug from the mouth of a healthy rat). It's a limited but ever-present risk of rat ownership, and one that can be greatly reduce by avoiding kissing rats, preventing bites, proper wound care should bites occur, and ensuring that physicians know about potential rat contact if illness develops.
I've written about this topic before, but it's an important (and increasingly common) issue to understand, so bear with me while I address the subject again.
I typically get multiple case consults in person, by phone or by email about methicillin-resistant (MR) staphylococci every day. A lot of these start with "I have a case with an MRSA infection..." While trying not to be rude, I tend to interrupt the conversation at that point with "Is this actually Staph aureus or another staph?"
I do this for a few reasons:
- A few years ago, the vast majority of "MRSA" infections in dogs, cats, horses and other companion animals were actually MRSA - that is methicillin-resistant Staphylococcus aureus. However, in the past few years, there's been a tremendous upsurge in other MR-staph, particularly booming numbers of MR-Staphylococcus pseudintermedius (MRSP) infections in dogs. These days, if it's a dog or cat, when I ask the "What staph is it?" question it's usually not actually MRSA. We're starting to see more MRSP in horses too, complicating things in that species as well.
- Staph are divided into two groups, coagulase positive species (which include S. aureus and S. pseudintermedius) and coagulase negative species. The coagulase negative species are commonly found in or on healthy animals and are often methicillin-resistant, but they are not very virulent and don't usually cause disease outside of very high risk populations (e.g. very sick animals in a veterinary hospital). If a MR coag-negative staph is isolated, I am far from convinced it's the culprit, and typically the real cause of the problem still needs to be found.
- MRSA is much more of a concern from a public health standpoint, as it can move between animals and people. While MRSP can cause human infections, these are extremely rare.
- MRSA is not really adapted to live in dogs, cats, horses and many other animals. It can, for a while, but doesn't do so longterm, and the vast majority of MRSA carriers will get rid of it on their own. In contrast, it appears that MRSP (at least in dogs) can stay with the animal for a very long period of time. Therefore, an animal that has had an MRSP infection has a reasonable chance of shedding the bacterium for a long period of time, which might be of relevance for its health in the future.
- The two main MR-staph of concern in companion animals are MRSA and MRSP. Some diagnostic labs still don't try to differentiate the two, despite the fact that there are different guidelines for determining whether they are methicillin-resistant. If someone has a result that doesn't differentiate MRSA from other staph, I tell them their lab isn't doing things right and they need to talk to them so they can have confidence in the results.
More information about MRSA and MRSP can be found on the Worms & Germs Resources page.
The latest edition of the journal Orbit (a journal dealing with eyes, not planets) describes an uncommon infection linked to a pet dog. The article (Zuberbuhler et al 2012) outlines 'acute unilateral dacryocystitis' in a 23-month-old girl (translation: .acute=sudden, unilateral=one side, dacryocystitis=inflammation of the nasolacrimal system, which is made up of a small sac and duct that runs from the eye to the nose).
In this case, the child had been playing in a gated children's area in a city park. At one point, she rubbed her eye after touching the ground, and shortly after the parent noted that the area around her eye had dog feces on it (not sure how they confirmed it was dog feces, but it's a logical guess). Two days later, she was taken to an emergency room because of severe swelling around the eye. A culture from the eye detected Pantoea, a bacterium that can be found in the intestinal tract of many different animal species (including people). It is a rare cause of disease but can cause infections when given the chance (such as being rubbed into an eye, or a wound, or other compromised sites).
While the bug and the infection may be a bit unusual, it's far from surprising to find an infection caused by fecal contamination. It reemphasizes the importance of basic hygiene measures such as hand washing (especially when feces are involved) and supervision of children, along with responsible pet ownership to prevent fecal contamination (i.e. picking up after your dog), particularly in enclosed children's playgrounds.
Yet another outbreak of salmonellosis traced back to pet turtles has been investigated by CDC and Pennsylvania's State Health Department. Pet turtles are notorious Salmonella vectors, for several reasons, including the fact that small aquatic turtles very commonly carry the bacterium, they are marketed towards young kids (who are increased risk of infection), and people tend to use poor (or no) hygiene practices when handling turtles or having contact with their environments. Efforts to restrict the sale of small (less than 4-inch long) turtles have greatly reduced Salmonella infection rates in people in the US, but have come under continual pressure from the turtle breeding industry, and the regulation is often flaunted by pet stores and road-side turtle sellers.
From August 5 to September 26, 2011, 132 cases of Salmonella Paratyphi B infection were identified in 18 US states.
- The median age of infected individuals was 6 years, and 2/3 were less than 10 years of age. This is consistent with a pet-associated outbreak.
- 56 patients (and their families, presumably) were interviewed, and 64% of them reported turtle exposure. That's a lot higher than one would expect if a random sample of the general US population was surveyed, and suggests that turtles were an important source.
- Of the 15 people who could provide details about the turtle, 14 of them described turtles that would have been too small to be legally sold in the US. This isn't surprising, and shows both the risk associated with these small turtles and the fact that this law is being widely ignored.
- The same strain of Salmonella was isolated from turtle tank water in five homes (it's not clear if only five were tested or if there were some negative tanks too). That's further evidence implicating the turtles.
This is yet another reminder of the risks posed by small turtles, particularly to young kids. Small turtles have high Salmonella shedding rates, are easy to handle and are even small enough for kids to put in their mouths (yuck!). That's a bad combination.
In 2007, Louisiana turtle breeders sued to reverse the FDA's small turtle ban. Fortunately they weren't successful, however it's clear that the turtle ban needs to be enforced, but that's hard to do. Perhaps more important, then, is increasing public awareness of the risks. If people are better informed of the issues, they can make better decisions about acquiring pets and how to properly manage them. One such resource for the public is the Turtles fact sheet that we have freely available on the Worms & Germs Resources page.
Norovirus sucks. It's been a while since I had it, but it doesn't conjure up fond memories. A bunch of Canadian tourists returning from Cuba (and presumably all of the other people on their planes) can also attest to the unpleasant nature of this viral infection.
Norovirus in people is (logically) caused by human norovirus. There are some other types of norovirus that infect other species, but the human version predominantly infects people. Predominantly doesn't mean always, though, and other hosts of the virus need to be considered. A recent study published in the Journal of Clinical Virology (Summa et al 2012) looked at whether human norovirus could be found in dogs. Researchers collected fecal samples from 92 indoor pet dogs in Finnish households where people had vomiting and diarrhea or where the dog owner had had close contact with someone with norovirus. Fecal samples were tested for the presence of the virus using molecular tests.
Norovirus was detected in feces of 4 of the 92 (4.3%) canine fecal samples. All positive dogs were from households that had more than two sick people. Additionally, kids were present in all households with positive dogs. Two of the dogs had been sick, with nausea and loss of appetite. Illness in the dogs was pretty mild and only present for one day, and it's not clear whether norovirus was responsible. Fecal samples from owners were only available from one of the positive households, and there the same norovirus strain was found in the owner and the dog.
These results are interesting and indicate that a small percentage of dogs in contact with people with norovirus can shed the virus. The big question is, "what does this mean?" That's not so clear. Finding norovirus in the dogs' feces is one thing. Determining that it's relevant to human (or animal) health is another, and it's important not to over-interpret the results, because...
- The testing that was used detects norovirus RNA, i.e. genetic material from the virus. That means that the virus passed through the intestinal tract. It does not necessarily mean that live virus was present, since this type of testing detects both live and dead virus. Dead virus obviously poses no risk to anyone.
- Even if live virus was being passed in the dogs' feces, the amount of virus coming out the rear end of the dogs isn't known. It might be pretty low and therefore of less concern.
- The relative risk posed by the household dog is a big thing to consider. All dogs that were shedding the virus were from households with multiple sick people, therefore they were already in pretty biohazardous environments with lots of virus being tossed around (in many different ways). This suggests that it may take a lot of exposure for dogs to shed (potentially only a little) virus. Also, it minimizes the relative risk posed by the dog, since if only dogs from severely affected households shed the virus, the dog is only one of many possible sources and probably of lesser risk than exposure to sick people and environmental surfaces they contaminated. Dogs from households with active disease are probably not very likely to encounter lots of other people or dogs (probably less so than the people in the house), therefore limiting their potential role in transmission. There's no evidence that dogs are long-term carriers of norovirus.
Does this change what you should do if you have norovirus? Not really. It means you should try to limit contamination of the environment, wash your hands frequently, stay away from others as much as possible and avoid puking on your pets. Maybe we should add "keep your dog isolated along with you," just in case.
Another interesting finding was the association between sick kids and norovirus-shedding dogs. It's further evidence of the "kids are biohazardous" theory. We know that kids are at increased risk of various infectious diseases. At the same time, we have previously shown that contact with kids is a risk factor for dogs shedding Clostridium difficile and MRSA. Whether that's because kids are more likely to be shedding these bugs, they have closer contact with pets, they pay less attention to hygiene or a combination of these isn't clear, but this result isn't particularly surprising. (No, I'm not recommending banning kids from pet-owning households. As parents, we know our kids are effective disease vectors... that's just part of having kids.)
This study doesn't tell us whether pets are sources of human norovirus, and we really shouldn't expect it to. A single study rarely answers all the questions, and good studies sometimes raise more questions than they answer. This is an interesting study and it shows that more work is indicated to clarify the answers to the questions raised above, and to determine whether there is any real concern about dogs and this nasty virus.
An article in the Winnipeg Free Press by Dr. W. Gifford-Jones, MD, talks about recurrent yeast infections in women. It covers several pertinent points, such as the fact that lots of women who think they have yeast infections actually have different types of infections, and that over the counter treatment might be a concern because of the lack of a proper diagnosis.
Why mention that here? Because of a little anecdote at the end of the story (and one that's gathering the most attention).
'My colleague, faced with repeated failure, decided to ask if his patient had an animal living with her. She replied she did have a small dog and the dog did, in fact, enjoy the comforts of her bed on many occasions. But that was nothing new. It was only after intense probing that she finally admitted with embarrassment to teaching her dog a trick. Since she was away all day at work, she had taught the dog to urinate in the bathtub! The dog had a yeast infection!'
Good for them for thinking about pets. It may have taken time to get there, but at least the question came up. However, this may be yet another example of finally asking the question but stopping the thought process too soon.
Was the pet a possible source of recurrent yeast infection in the person? I can't discount the possibility. We really don't know much about the potential for transmission of this kind of infection, but the pet could have been contaminating the bathtub, leading to subsequent exposure of the person.
Did the pet really have a yeast infection? That's an important question, since they just finished saying a lot of women who think they have a yeast infection don't actually have one. I wonder whether the yeast infection was properly diagnosed by a veterinarian.
Was there any evidence that, if they both had an infection, the same bug was involved? Probably not. However, if you really want to know if the pet is potentially involved, a culture of both the pet and owner to see if the same yeast is present would be needed. Is it really worth doing? Perhaps, because if the pet and person have different yeast, it means that the MD needs to keep looking for possible causes of recurrent infection.
Could the pet have been getting infections from the owner? Possibly. If a pet and person have the same infection, and it's not an infection that classically originates in a pet, then you have to consider the direction of transmission. If the woman had recurrent yeast infections, she could have been regularly contaminating the tub, where the dog could have been exposed when peeing.
It's an interesting case that should raise some questions and hopefully lead to more thought about pets as a potential source of infection in cases like this, but at the same time, a more thorough investigation as well.
Following reports of a veterinarian warning colleagues and horse owners about West Nile infection in a British Columbia horse, Dr Brian Radke, a Public Health Veterinarian at the BC Ministry of Agriculture, has clarified the situation.
"The BCCDC co-ordinates WNV surveillance for the province of BC including monitoring of mosquitoes, birds, horses and humans. The BC Ministry of Agriculture supplies information to BCCDC on horse cases. In Canada, equine cases of WNV are reportable the Canadian Food Inspection Agency (CFIA).
The CFIA has no reports of WNV consistent with the Prince George horse. Discussions with the veterinary practitioner have clarified that the horse's illness, which occurred in November, was not due to WNV.
The testing discussed in the article was not conducted at the provincial government animal health laboratory. The BC Ministry of Agriculture is following up to determine the nature of the WNV testing and the appropriate interpretation of the test results.
BCCDC WNV surveillance indicates the following:
- In 2011 no humans, mosquitoes, or birds were detected with WNV infection in BC. One horse in the Central Okanagan was reported as positive and that report is under review.
- There have been no positive WNV indicators in the Prince George area.
- In BC, WNV has been detected in southern parts of the province, all below N50 latitude. (By comparison, Prince George is N54 latitude.)
- Risk modelling by BCCDC suggests that Northern BC, including Prince George, experience insufficient sustained heat during the short summer for WNV to amplify and be transmissible by the low density of vector mosquito species.
- The risk modelling also suggests that even in the warmest (that is, southern interior) areas of the province, the risk of WNV infection decreases significantly in September as the vector typically ceases seeking blood meals.
The BC Ministry of Agriculture and BCCDC look forward to working with the province's equine practitioners to interpret WNV testing results and epidemiology to assess the risk of WNV to horses in the various regions of BC. The assessment of risk could then inform decisions about the appropriate interventions for WNV infection in horses in the various regions."
We thank Dr. Radke for the information.
Pasteurella multocida is a bacterium that's commonly found in the mouths of dogs and cats. It's a common cause of cat and dog bite infections in people, but can also be spread through close contact with pets (without bites). It's logical to assume that the closer the contact, the greater the risk of transmission. A recent report in Clinical Infectious Diseases (Myers et al 2012) describes three people with life-threatening Pasteurella infections. A unique aspect was all three people got sick from nursing dying pets.
- A 55-year-old woman with sore throat, fever and difficulty swallowing was diagnosed with epiglottitis (inflammation of the epiglottis, a part of the throat region) and hospitalized. Pasteurella multocida was identified on a blood culture. It was subsequently revealed that she had provided palliative care to her dying dog. As part of this, she was dropper-feeding the dog honey, and also eating honey with the dog from the same dropper.
- A 63-year-old woman with sore throat, difficulty swallowing and hoarseness was diagnosed with uvulitis (inflammation of a different part of the throat region) and narrowing of her airway. As with Case 1, P. multocida was isolated from her blood. Her cat had died six weeks earlier and she had "continuously held, caressed, hugged and kissed her cat during its last 7 days of life."
- A 66-year-old woman was hospitalized with fever, chills, cough and difficulty breathing. She had severe pneumonia and P. multocida was grown from a sample of respiratory secretions. Two weeks before she got sick, she had provided palliative care for her dying cat, by "holding, hugging, and kissing the head of the cat and allowing the cat to lick her hands and arms."
Fortunately all three women recovered from their infections, but the severity of disease is certainly a concern. As is common, there was no attempt to see whether the implicated pets actually carried the same Pasteurella multocida strain as the owners, but here the authors at least had a good excuse, since all of the pets had died before the owners got sick.
There are some interesting points in the Discussion section of the paper.
"Our 3 patients’ histories of having recently provided palliative pet care to their dying animals were obtained only after P. multocida was identified in cultures and only after subsequent detail-oriented, animal contact histories were obtained."
- Pet contact (or animal contact in general) is still not asked enough by physicians investigating unknown illnesses. It's unclear whether it would have made a difference in these cases, but knowing more and knowing it earlier can help speed the path to the right diagnosis. Here, pet contact was only considered after a pet-associated bacterium was identified.
"Simply asking whether or not the patient had a pet would not have uncovered the defined association of these respiratory illnesses with palliative pet care. The patient with P. multocida uvulitis even denied having a pet (it had died 6 weeks previously) and only admitted to having provided palliative pet care when asked specifically if she had any animal contacts in the past 3 months."
- This shows some of the challenges and how care must be taken when asking about pet contact. Simply asking "Do you have a pet?" doesn't cover it.
"Only diligence and very detail-oriented, pet-related histories will likely uncover further patients with invasive P. multocida infection related to the pet owner’s provision of palliative pet care to dying animals."
- This shouldn't be focused on palliative pet care, since that's a minor component of pet contact. Many other people have close contact with their pets, even when the pets are healthy. It's something that should be considered at all times.
A Prince George, British Columbia veterinarian is warning other veterinarians and horse owners about West Nile in the province. Little information is available at this point, but the warning is in response to a diagnosis of West Nile infection in a horse from the area. The report calls it a "deadly disease" but it would be more appropriate to call it a "potentially deadly disease," since most horses that are exposed don't get sick, and many sick horses recover. I don't want to downplay the seriousness of West Nile, but it's important to keep it in perspective and make people panic.
The BC CDC has an ongoing West Nile surveillance program because of the obvious concern as this virus has worked its way across North America over the last decade. While it's taken it's time getting to BC, West Nile virus has been identified in the province, and only time will tell whether it becomes a serious health concern for horses or people. The latest update of the BC CDC surveillance data indicates one positive horse, but no positive humans (of 415 tested) or mosquito pools (2282 tested). The one equine case that was documented was from Central Okanagan. The horse had clinical signs consistent with infection, although the severity and outcome are not reported.
It's unclear to me whether this Prince George case is something that's happened just recently or whether the horse was sick. It's pretty late in the year for a mosquito-borne virus, but not impossible in some areas.
Does this report mean that horse owners in BC should be concerned? Maybe. "Aware" might be a better term.
Horse owners and veterinarians always need to be aware of the infectious disease risks in their area, and areas to where a given horse may travel. Keeping apprised of ongoing West Nile virus surveillance can help determine the likelihood of exposure, but that doesn't mean you can wait until there's a case next door before you do anything. (Someone has to have the first case in an area, and you don't want that to be you.)
Whether or not to vaccinate against this virus depends on the likelihood of exposure and risk aversity. Available vaccines are rather safe and effective (not 100% on either account, like any vaccine, but quite good overall), and vaccination decisions should be made based on a well-reasoned discussion between veterinarian and owner, considering a variety of factors such as where the virus has been found and how much risk everyone is willing to take.
The news report has a quote recommending vaccination in the spring. That's the typical time people vaccinate against mosquito borne diseases, but that's not my recommendation. For me, the goal is to vaccinate so that peak immunity is present at the time when exposure is most likely. West Nile virus is classically a late summer/fall disease, based on mosquito types and their biting patterns. For that reason, I like to see horses vaccinated a little later in the year - closer to the high risk period. Again, it's important to know disease trends in each region to make the most informed decision.
So, horse owners in BC should be aware but not panic. A good discussion about vaccination and about general mosquito avoidance practices should be the first thing that happens.
Although the weather in Southwestern Ontario seems quite confused lately regarding whether it wants to be winter or spring, at least we're still a few months off from having to worry about mosquitoes and the viruses they carry once again. Warmer parts of the world, however, are in the midst of their mosquito season, and some chickens are lending a hand to give people in the area a "heads up" about what's around.
The Health Department of Western Australia has detected Murray Valley encephalitis virus (MVEV) in chicken flocks in East Kimberley. The department has also tested and found the virus in its sentinel chickens in Wyndham and Kununurra. These sentinel birds play an important role as an early warning system when viruses like MVEV are circulating in the area. Just like West Nile virus, MVEV typically circulates between birds and the mosquitoes that like to feed on them, but problems occur when the same mosquitoes start to bite people (or other susceptible animals such as horses), particularly when there are a lot of mosquitoes, like when the weather is very wet or when there's been flooding. Although most people who are infected with MVEV or WNV fight off the virus with no difficulty, or may simply develop short-term, non-specific signs of illness like mild fever and malaise, in some people these viruses can cause severe infection of the brain (encephalitis) and may even be fatal.
Knowing that MVEV has been found in these "guardian" chickens lets people know (via warnings issued by the health department) to take extra precautions against mosquito bites, such as:
- Staying indoors during peak mosquito activity - dusk and dawn
- Wearing protective clothing including long-sleeves and long pants
- Applying insect repellent
In North America, you can pretty much substitute West Nile for Murray Valley in a case like this. Sentinel chickens have been used to provide early warnings of circulating WNV here, before cases are detected in people or horses. Another means of early detection that is also used is testing pools of mosquitoes directly.
It just goes to show you can still be an important part of the country's defenses, even if you're a little chicken :p
Case reports of infections acquired from pets are sporadically found in the human medical literature. A common problem with these reports is the failure to look for true evidence of zoonotic transmission. The typical thought process is "We found this bug in a person, it's most often found in animals, so this person must have gotten it from their pet." Often, this likely is actually the case (although some evidence would be nice). In other instances, like the Pasteurella bone infection described in the Orthopedics paper I wrote about recently, this assumption is probably completely off-base.
Something that is usually missing from these reports is any investigation of the suspected pet. Finding the bacterium in question in/on the pet, and showing that it's the same strain as was found in the person goes a long way to supporting the conclusion that the pet was the source. It's not a 100% guarantee, since you can't say whether it went from pet-to-person or person-to-pet, but with a typically pet-associated bacterium its much more likely to have come from the pet, so finding the same strain in both pet and person is pretty solid evidence. Most case reports don't bother even trying to get this much information (but they still get published...).
A case report in an upcoming edition of Zoonoses and Public Health (Register et al 2012) is another example of a study that provides some information about a potential pet-associated infection, but stops short of the type of proof that is needed. To their credit, the pet wasn't available for testing and they are clear that it's a "possible" case of zoonotic transmission, which puts them a step up on other studies, but it's still too bad the additional information couldn't be reported.
The case report describes an 11-year-old girl with cystic fibrosis (CF). People with CF are at greatly increased risk of respiratory infections, including infections caused by microorganisms that typically don't cause disease in other people. This child had a sputum sample collected during a routine doctor's visit, when she didn't have any signs of respiratory infection. Bordetella bronchiseptica, a bacterium most often found in dogs and cats (and one of the causes of kennel cough (aka canine infectious respiratory disease syndrome) in dogs), was isolated from the sample. When this was explored further, it was revealed that child's family had obtained a new kitten three weeks earlier, and the kitten had signs of respiratory disease.
Unfortunately, the kitten had been removed from the household by the time B. bronchiseptica was diagnosed in the girl, so it couldn't be tested. (They don't say why the family got rid of the cat.) However, the authors at least took it a step further and did some detailed molecular characterization of the bacterial strain they recovered from the sputum sample. Different genetic traits suggested that the strain was feline in origin, and, combined with the fact that the child had contact with the kitten, this provided a little more support to the hypothesis that the cat was the source. It's not proof, but still interesting. They also determined that the B. bronchiseptica strain was missing a gene that's associated with helping cause disease, suggesting it's not as able to make people sick. That might explain why the child was carrying the strain in the absence of disease, although people can carry lots of different bacteria that can potentially cause disease without being clinically ill.
In the end, it was an interesting little report and the authors conclude with a couple of good statements:
"Acquisition of detailed clinical and epidemiological data paired with discriminatory genetic comparison of case isolates and contact isolates is needed to more firmly establish transmission patterns and identify likely contact risks." (A fancier way to say what I said above.)
"...it seems advisable to counsel CF patients regarding adherence to practices that minimize opportunities for zoonotic transmission of B. bronchiseptica from family pets or other potentially infected animals."
Headshaking is a frustrating problem in horses. It's often hard to identify a cause and treatments are frequently unrewarding. Many different possible causes of headshaking have been proposed, including equine herpesvirus type 1 (EHV-1) infection.
As is common with herpesviruses, EHV can lie dormant in the body, and it may be re-activated during times of stress. There's ample evidence that other herpesviruses can cause nerve pain with reactivation. In humans, re-activation of the varicella-zoster virus (the herpesvirus that causes chickenpox) causes shingles, which is a very painful disorder. Since dormant EHV-1 can be found in nerves in a horse's head, it has been suggested that pain caused by reactivation of dormant virus could be a trigger for headshaking.
A recent study published in the Journal of Veterinary Internal Medicine (Aleman et al 2011) investigates this theory. The researchers looked for the presence of EHV-1 in trigeminal ganglia (a group of nerve "nodes" in the head) in headshaking horses and healthy controls. While it was only a small study, there was no evidence indicating a role of EHV-1 in headshaking, since the virus was only detected in 1/8 headshakers compared to 0/11 controls.
This study doesn't absolutely rule out EHV-1 as a cause a headshaking, since it still could be one of many potential causes that is involved in only a minority of cases. However, this study suggests that EHV-1 is not a particularly common cause of headshaking, if it causes it at all.
No, not gravy made from bearded dragons (a type of reptile), but foodborne Salmonella with a link to the reptile.
Reptiles are an important source of Salmonella, which is why standard guidelines recommend that high-risk people (e.g. children less than 5 years of age, elderly individuals, people with compromised immune systems, pregnant women) not have contact with reptiles or have them in the house. A report in Zoonoses and Public Health (Lowther et al 2011) highlights another possible risk.
The report describes a Salmonella outbreak that was traced back to a potluck dinner. Nineteen cases were identified, 17 primary cases (people that attended the dinner) and two secondary cases (household members of people that attended the dinner). Overall, 29% of people that attended the dinner got sick. A further 18 people had some intestinal disease but strictly speaking didn't fit the definition for a case (however it is suspected that they were part of the outbreak). Salmonella subspecies IV (a type mainly associated with reptiles) was isolated from the stool of five people, confirming the occurrence of an outbreak.
As is typical, food consumption history was evaluated. Sixteen of the 17 primary cases reported consuming turkey gravy, which was a statistically higher proportion than that of people who did not get sick. The gravy was made at the private home of a person who didn't attend the dinner. This was the only home of the people involved where reptiles were kept. Two healthy bearded dragons lived in the house, in a terrarium in the living room.
The investigation focused on the reptiles, since the Salmonella strain found is typically associated with reptiles, and the turkey (the source of the gravy) had no evidence of Salmonella contamination based on testing. Samples from the environment of the household where the gravy was made were collected, and two types of Salmonella were identified. One of these Salmonella types (Salmonella Labadi, which was different from the outbreak strain) was isolated from one of the bearded dragons, as well as the inside and outside of the terrarium glass, other terrarium surfaces, surfaces around the terrarium, the bathroom sink drain and kitchen sink drain.
A common question that comes up when people have reptiles and high risk people in the house is "If I don't take the critter out of the cage, I should be ok, right?" Unfortunately, that's not true. Human Salmonella infections have been clearly identified in situations where reptiles don't leave the terrarium because (as was the case here), while the reptile may not leave the terrarium, Salmonella often does.
The person who made the gravy said that the bearded dragons had not been out of the terrarium when food was being prepared. A child was responsible for feeding the reptiles and cleaning the terrarium, and was supposed to use the bathroom for terrarium cleaning. However, it was reported that the reptiles' dishes "might have" been cleaned in the kitchen sink during the the day period when food was being prepared for the party.
The overall conclusion was that this outbreak "probably resulted from environmental contamination from bearded dragon faeces." It's a reasonable conclusion. Even though the same Salmonella strain wasn't found in the reptile, it makes sense because the reptiles were the most likely source of environmental contamination in the household, and that was the most likely source of the foodborne contamination. Reptiles can shed various Salmonella strains and they can shed intermittently. It takes multiple samples over time to get a real idea of the scope of Salmonella shedding, and I assume that one or both of these reptiles were shedding the outbreak strain at some point.
How can something like this be prevented, since the standard recommendation of having high risk people avoid contact with reptiles doesn't apply to this type of situation?
- Good hygiene practices should be used when handling reptiles and their environments. In particular, there should be proper attention to hand hygiene after contact with reptiles or their cages.
- Reptiles should not be allowed in the kitchen. Ever.
- Food and water bowls should not be cleaned in kitchen sinks. Terrariums should not be cleaned in kitchen sinks. Ideally, they shouldn't be cleaned in bathroom sinks either. (If possible they should be cleaned outdoors with a hose.)
- Good food handling practices are critical. Here, gravy wasn't re-heated to a high enough temperature to kill the contaminating Salmonella. Adequate re-heating would have prevented this outbreak.
Bob Katter, an Australian Member of Parliament and leader of the Australian Party, has proposed culling flying foxes (fruit bats) as a way to control Hendra virus, which is spread by these large Australian bats. He's not the first person to make such a proposal, but it's a knee-jerk reaction that in reality doesn't make a lot of sense.
It's not completely clear whether Mr. Katter is proposing a plan to completely eradicate the flying foxes altogether, or to simply let people kill any such bats they find on their property, but neither approach is likely to be effective in terms of decreasing the risk of Hendra virus transmission.
If people kill flying foxes on their property, they'll just be replaced in short order by bats from neighbouring areas.
Trying to eradicate the entire species is a bad idea for a variety of reasons:
- Tinkering with a complex ecosystem doesn't often turn out the way you want it to. Australians certainly know from past experiences that bad things can happen when new species are introduced (rabbits are just one example). The same might happen when a species is removed.
- Eradication of the species is probably impossible or at least very difficult. I don't know much about the reproductive rate of flying foxes, but if the species can reproduce at a reasonable rate, they can probably replace the culled animals unless people are really aggressive and seek out all remote breeding sites. The limitations of culling have been clearly shown in rabies control, where it doesn't do much because culled dogs are quickly replaced by new dogs.
- Eradicating flying foxes would be very expensive. What could that money do if put into research on vaccination, treatment, and other worthwhile ventures? What if efforts were focused on eliminating flying fox roosting sites in horse pastures? Overall, the impact would probably be much greater.
Why stop with flying foxes? Australia has lots of nasty critters, ranging from spiders to saltwater crocodiles. Should we kill all of those too? Dog bites kill more people than Hendra every year. Should we kill all dogs?
Hendra virus is not something to ignore. While infections in horses are rare, they are usually fatal and there's the risk of transmission to people. Human infections are very rare but often fatal. So, ways to reduce infection of horses as a means of reducing both human and horse disease are important, but the slaughter of flying foxes doesn't make a lot of sense.
The Redlands Animal Shelter in California is looking into bird control measures after blaming Giardia infections in dogs on exposure to wild bird poop. On Facebook, Redlands Friends of Shelter Animals have declared "We have a serious problem with birds at the shelter. They land on the kennels and poop goes into the water bowls and give the dogs giardia - which is a parasite that gives them explosive diarrhea."
Giardia is a protozoal parasite that can cause diarrhea in dogs and other species. It can also be carried by healthy dogs, at relatively high rates in some groups. The scope of the problem at the Redlands shelter isn't clear since the news article only talks about one case. Whatever the scope, shelter management is blaming the birds.
Apparently, discussions are underway with different companies about a solution to the bird problem, something that is anticipated to be expensive. However, it's all too common for people to jump the gun on expensive interventions when there's an outbreak and overlook the root causes. While news reports don't always give the whole story, I'd be wary about blaming birds without much more evidence.
Can wild birds carry Giardia? Yes. However, there's more to the Giardia story than that. It doesn't sound like they've actually tested the bird feces to determine whether Giardia is there. Additionally (and critically) it doesn't sound like they've determined the type of Giardia that's infecting the dogs. There are different types (assemblages) of Giardia and most have a limited range of species they can infect. The vast majority of dogs with Giardia in most regions are infected by Assemblage D, a dog-specific strain that comes from other dogs and poses no risk to people. I'm not aware of Assemblage D being found in birds. Dogs can also be infected by Assemblage A, a type that infects people, and also can infect birds.
So, if Assemblage D is involved, they need to look at transmission between dogs within the shelter. If Assemblage A is involved, they still need to focus on dogs but could investigate birds as a potential source.
Overall, Giardia transmission is much more likely due to breakdowns in cleaning, disinfection, hand hygiene and general shelter practices rather than birds pooping in water bowls. It's a lot cheaper to address these shelter management practices (which will also help control various other infectious diseases) rather than dumping a lot of money into controlling bird exposure when in fact that may not be causing the problem. Trying to reduce exposure to bird poop is a good thing as a general practice, but it's important to focus efforts and resources on finding and addressing the true root problems during an outbreak.
More information about Giardia can be found on the Worms & Germs Resources page.
It's been a while since I wrote about petting zoos. Part of the reason is that the state of petting zoos in this area has improved quite a bit over the past few years, so I haven't been coming home from fairs or other events with a need to vent. However, improvements are not universal, and even with improved conditions, there are always going to be disease risks associated with petting zoos and other events where people have contact with animals.
This week's edition of Morbidity and Mortality Weekly Reports (a rather gruesomely named but very interesting publication by the US CDC) describes a 2011 outbreak of E. coli O157 from a North Carolina State Fair. After receiving reports of infections in four people who had attended the fair, an investigation was launched. Here are the highlights:
- A total of 25 suspected cases were ultimately identified. (Usually, there are many more milder cases that go undiagnosed). Stool samples were collected from 19 of these individuals and the same strain of E. coli O157 was confirmed in 11 of them.
- Affected people ranged from 1-77 years of age.
- Eight people (32%) were hospitalized. Four of those had hemolytic uremic syndrome (HUS), a severe form of disease caused by E. coli O157.
- When compared to people who did not get sick, having visited one of the buildings were sheep, goats and pigs were housed for livestock competitions was the only risk factor identified. While the public was not supposed to have contact with animals in those buildings, 25% of people reported having had direct contact with animals anyway.
An investigation like this often can't determine the source of the pathogen with 100% accuracy, because the investigation occurs after the fact (sometimes long after). That means the animals aren't around anymore for testing, the area/fair may have been cleaned up already, and people may not completely (nor accurately) recall exactly what they did. Regardless, it's quite suspicious that contact with this particular building was the root of the problem. How people became infected isn't clear. Some had direct contact with animals, and that's an obvious potential source. Cattle are the most common source of E. coli O157, but it doesn't appear that any were present in the building. Sheep and goats are a more likely source than pigs. Other people could have been infected through contact with contaminated surfaces in the building, something that has been documented in other outbreaks.
After a large 2004 petting zoo outbreak at this same fair, the state passed a law (named Aedin's Law, after a child who became seriously ill) that set strict requirements for animal exhibits where contact with the public is intended. This facility was not subject to Aedin's Law because animal contact was not intended (even though it was apparently common) and a multiagency task force is looking into additional measures for exhibits where animal contact might occur.
Cost/benefit is an important issue when it comes to infectious disease control. There will always be some risk of disease when interaction with animals is allowed. We can take measures to reduce the risk, but never eliminate it. Therefore, the key is maximizing the benefit and minimizing the risk. Animal contact at fairs and similar events can be very rewarding for some people, so most people will accept some degree of risk. This outbreak involved a relatively small number of people, particularly when you consider approximately 1 million visitors attended the fair. The infection rate was really very, but with a potentially life-threatening disease, it's not something that should be ignored.
As is the case here, infection control is often reactionary, with changes only taking place after problems occur. However, it's good to see that actions are being taken (at least in NC) to reduce the risk of this happening again.
While you don't want to read too much into a single case, 2012 has started off in a bad way for Queensland horses. Hendra virus was identified in a Townsville area horses that died. This zoonotic viral disease is largely restricted to Queensland, Australia, but it has a high fatality rate in horses (and people). Hendra virus is spread by fruit bats and is an ever-present concern to Queensland horse owners and veterinarians, but a mid-summer infection is quite unusual (remember that it's currently mid-summer in Australia). Most cases tend to occur from July to September - this case is a reminder that seasonal trends are just that: trends, not absolute rules.
Fortunately, the attending veterinarian used proper precautions when handling the horse to limit the risk of zoonotic transmission of Hendra virus. However, there will presumably be an investigation to determine who had contact with the horse and their potential for exposure. There is currently no way to prevent or specifically treat Hendra virus infection. An experimental antiviral treatment has been tried in the past, but it's effectiveness if far from clear.
Last year was quite bad in terms of the number of Hendra cases that were detected in Australia. Let's hope this early 2012 case isn't a sign of things to come.
The executive director of the SPCA of Niagara is under pressure from charges that he's "presided over the killing of hundreds of animals." As is common with shelter controversies, sorting through the emotion and rhetoric is difficult. At best, running a shelter can be a thankless task, due to the overwhelming number of animals, emotion, lack of understanding by the public (and often personnel) of the relevant issues, financial challenges and often poorly designed facilities. At the same time, bad things do happen in shelters, and it's critical to put in the time and effort to determine whether things are being done poorly and what needs to be fixed. Here are some of the issues from the Niagara situation.
"From Oct. 1 to Dec. 15, the local SPCA euthanized 473 cats and 100 dogs, a staggering total of killings, according to sources familiar with the situation at the Lockport Road shelter."
- Apart from the problem of relying on information from anonymous sources, it's hard to put this number into context. You need to know the overall number of animals that come in and the shelter's capacity. It's a sad fact that about 50% of cats are euthanized at most shelters internationally because of massive overload. Shelters shouldn't be cat warehouses. It does no one (including the cats) any good to stockpile huge numbers of cats that never have a chance of adoption, and it creates a perfect environment for disease outbreaks. So, while that number of animals seems high at first glance, it may just reflect the reality of supply and demand, shelter capacity and the health/adoptability status of the animals.
"When he was hired, Faso admitted, “My animal care experience is very minimal.”"
- A shelter director doesn't need to be an expert in shelters and animal health. In fact, some excellent shelter directors have come into the job with no experience whatsoever. Their job shouldn't be running animal care. They should be running the shelter, managing personnel, raising funds, liaising with the community and doing a host of other activities. The key is having good veterinary and animal care support, and a willingness to listen to those people. It would be great if every shelter manager was a veterinarian with a shelter medicine residency under his/her belt, along with an MBA and training in communications, but that's not going to happen. Someone with little animal knowledge but the ability to listen and take advice can be an excellent shelter director.
"McAlee and others tell horror stories of animals brought to the shelter for surrender or picked up on the streets and in need of medical care, who are then left to suffer in their cages. In one case, a cat that appeared to be suffering from a broken jaw was brought in and allowed to stay for a week in a cage without treatment. Finally, a concerned staffer took the cat to an emergency veterinary clinic where it was treated and then returned to the shelter."
- That's a big problem. If true, and if this was done because of pressure from the director overriding advice from medical staff, then that's completely inappropriate. Interference with medical decisions and medical care does occur in some shelters and is a major problem.
"When the cat then developed a common respiratory infection, rather than provide further medication for the animal, Faso directed that it be euthanized."
- This is a tougher issue. I hate to see potentially treatable animals euthanized, but euthanasia is an appropriate response in some situations. If they are unable to properly manage an infectious case or are overwhelmed with healthy cats, keeping an infectious cat may pose a huge risk to all of the other cats in the facility. It's impossible to say much here without more details.
"Other sources tell the Gazette that cats at the shelter have been injuring themselves in out-dated display cases and that a donor offered to fund the replacement of those cages. Faso, reportedly, refused to accept the donation."
- Poor housing is a common problem in shelters. Good cages are expensive. It would be bizarre for a shelter manager to turn down money (that came with no strings attached) and if that was done, it would be another sign that Mr. Faso's not right for the job.
"..he has reportedly told board members and others that the local SPCA will “never be a no-kill shelter because it’s too expensive."
- That's an unfortunate fact. No kill shelters just aren't viable in the grand scheme of things. Individual shelters can be no kill, but that's often done by cherry picking the adoptable animals.
It comes down to math. If 50% of cats coming into shelters are euthanized every year because of lack of space, to convert to a no-kill approach we'd need to massively increase shelter capacity every year to accommodate the increasing population. Millions of dollars would be required to create cat warehouses where millions of unadoptable cats lived marginal lives in facility confinement until dying of natural causes or from the massive disease outbreaks that would be certain to happen. I know I'll get reams of emails complaining about this paragraph, but to me it's a simple fact. If you increase supply by 100% per year by not euthanizing any animals, and demand doesn't increase, the math quickly shows you the size of the problem that would be created.
The only way to get to the point where no-kill is a viable approach is to have more responsible pet owners and better animal population control. Euthanasia rates are much, much lower in dogs, in part because of much better population control and also because people tend to try harder to recover lost dogs compared to lost cats. Recovery rates of lost dogs that make it to shelters are very high. Cats... not so much.
So, if you want to help out shelters and the animals in them:
- Spay and neuter your pets.
- Donate to good quality shelters to help them provide optimal care.
- Volunteer, if you have the time and interest.
- Hold shelters to a high standard, but make sure it's a realistic standard.
- Encourage municipalities to properly fund animal shelters and enforcement.
- Consider adopting from a shelter if you are getting a new pet.
- Take the time to learn about the issues, and make assessments based on fact, not just emotion.
It seems like pet bite articles come in waves, with a recent cluster showing the variable quality in advice that's available.
Often, they are holiday "filler" articles that provide some basic useful information but overall are of limited use or even harmful based on their very superficial approach. They often mention rabies, get a quick quote from a veterinarian or someone in public health, but don't emphasize the potential problems that can occur with even apparently minor bites. The thing that often raises my ire is the common statement about watching the bite and going to a doctor if your limb swells up or has pus oozing out, without talking about the need for proper post-bite care to actually prevent that from happening.
Anyway, I came across a couple of better articles recently, that get some good information across in a nice, readable manner. One, an article in "The Herald News" entitled "Cat bites always require check by doctor", gets a very important point across quickly.
The news story details the saga of the PJ, a 13-year-old cat, and his owner. PJ bit the woman on the arm causing a seemingly minor wound, but by the next day, her arm was red and swollen, necessitating a round of intravenous antibiotics and four days in hospital. In the article, Gail Steele, an infection prevention nurse, states "Cat bites.. must always be considered medical emergencies. This is especially true when they occur in the hand because that area has a richer blood supply...Their sharp little teeth are like little needles, and they inject bacteria right into soft tissue..."
This is a pretty extreme example of what can happen after a cat bite, but it's far from rare. It's not really clear whether this person's infection would have been prevented with normal practices. Bites over certain sites, like the hand, foot, joints, tendon sheaths and prosthetic devices, and bites to young kids, elderly individuals and people with compromised immune systems typically require prophylactic antibiotics.
If this was actually a bite over the arm, as reported, antibiotics might not have been given, even though cat bites are much higher risk for infection than dog bites. However, the key is that bites should be assessed so proper determination can be made about the need for antibiotics. All infections won't be prevented but appropriate medical care should reduce the risk and also allow for adequate consideration of whether rabies exposure might be a concern.
There's a sad end to this article, as PJ bit his owner again a few months later. The bite was over the shin and, given her previous problems, antibiotics were provided. However, the owner still ended up with an abscess that required surgical intervention and took months to heal. (Whether this person has really bad luck, whether PJ has a particularly bad mix of bugs in his mouth or whether the owner has an unidentified problem with her immune system is unclear, but back-to-back severe infections is a major issue, especially with a cat that is prone to biting.) The woman's daughter ended up taking PJ home with her, but after another unprovoked bite, he was euthanized.
Cat bites aren't always this bad, and in fact, most don't result in complications. However, that's not to downplay the potential problems. When you consider how often cats bite, how often cat bites are not properly cared for because they appear to be minor, and the ability of a cat bite to inoculate bacteria deep into the tissues, it's easy to see how bad things can happen. Reducing the risk of cat bite infections involves a few basic steps:
- Reducing bites. Good handling and training (of both cats and people) can reduce the likelihood of bites. This is particularly important with kids, who may be bitten through rough or excessive handling of a cat.
- Bite first aid. Prompt cleaning of the wound can reduce bacterial contamination. Thorough cleaning with soap and water can have a big impact on the likelihood of infection.
- Medical care. Bites over certain sites or to certain individuals (see above) almost always require antibiotics. There's less consensus over other types of bites, but getting medical care is a good idea in any case to determine if there are any factors that indicate a need for antibiotics.
- Rabies avoidance. Every bite should be reported to public health so the rabies aspect can be covered. The biting animal needs to be identified and observed for 10 days. If it's healthy after 10 days, it couldn't have been shedding rabies virus. If the biting animal cannot be identified, it's likely that post-exposure treatment for rabies will be required.
I avoided the "snakes on a plane" title, as ever since the (bad) Samuel L. Jackson movie came out, every reptile smuggling headline seems to use use it. Regardless, would you like to be on a long trans-Atlantic flight with 247 smuggled animals, including a collection of venomous vipers? Probably not.
Fortunately for passengers on a flight from Buenos Aires to Madrid in early December, security screeners took note of the "organic substances moving inside" Karel Abelovsky's baggage. Inside, they found over 200 reptiles and mollusks, including 15 venomous vipers. Among these were two yararas (Bothrops jararaca), a viper that can grow up to 160 cm (~5 ft) in length, and which is a common cause of snakebites in some regions. Two of the animals were dead by the time they were found. Probably many (or most) of the others would have died during transit.
Animal smuggling is a big problem for many reasons:
- It's an major animal welfare issue, since it is reasonable to suspect that only a small minority of smuggled animals survive the process, and even fewer thrive in their new homes.
- Smuggling of endangered species can threaten survival of some species in the wild.
- Smuggling of venomous or otherw