Dog cull considered in Israel
Israel has experienced a major upswing in canine rabies cases since 2009. There had been a significant decline since 2003, when oral rabies vaccination of foxes was started, but the recent increase has been in dogs and jackals, not foxes. Now, stray jackals and dogs are the main rabies vectors in northeastern Israel, the area affected by the current outbreak.
Stray dogs are a significant concern in terms of rabies because they can have close contact with humans and wildlife. Dogs are the most common source of human rabies internationally and thousands of people die each year from rabies acquired from dogs.
The increase in rabies in stray dogs and jackals has lead to discussions about how to control the stray population and reduce the risk of rabies. Previously, it was common for authorities to shoot strays in parks and nature reserves. This practice was stopped a while ago, however the Israel Nature and Parks Authority has now asked for permission to shoot strays in the interest of rabies control. The proposed regulations would allow strays to be shot in national parks, reserves, and "any other open area where wildlife species are considered at risk", but not unless their presence poses "an immediate discernible risk to wildlife and never within 1 km of human habitation."
This seems to be a wildlife protection program disguised as a rabies control program. The emphasis is on protection of wildlife, since packs of stray dogs have had major impacts on some endangered wildlife (e.g. fallow deer). It's not really a good rabies control program, since culling alone is unlikely to be effective, and only culling when the dogs pose a risk to wildlife and away from human habitation presumably would only have a limited impact on the prevention of human rabies. If they want to control the dog population to protect endangered species, they should just say that. If they want to control rabies, they need a comprehensive rabies control program that involves consideration of various approaches such as vaccination of strays and jackals, sterilization of strays, public education to decrease the risk of exposure, and vaccination of domestic animals. A cull alone won't cut it for rabies control.
Photo: A pair of Golden Jackals (Canis aureus) in Israel (photo credit: Michael Baranovsky)(click for source)
Leptospirosis in Michigan
Veterinarians are reporting an apparent spike in cases of leptospirosis in dogs in southern Michigan. Leptospirosis is considered a re-emerging disease in many areas of North America. This disease, caused by various types of the Leptospira bacterium, can affect many different species, including dogs and people. A wide range of illnesses can result, including fatal infections. In dogs, kidney failure is a common problem.
Classically, leptospirosis is diagnosed in dogs that spend time in the woods and similar areas, where they may be exposed to the bacterium from contact with the urine of infected wildlife. Different types of Leptospira have different animal hosts, and infected hosts can shed large numbers of bacteria in urine. These bacteria can survive in wet conditions for long periods of time, and other animals can be infected through ingestion of urine-contaminated water or contact of urine-contaminated water with broken skin (e.g. tiny cuts or open sores on their feet) or mucous membranes (eyes, mouth, nose).
Michigan vets have suggested that the recent spike in cases is the result of local highway construction, which may have driven rats out of their normal habitats and into areas that people and dogs frequent. That's possible, but it could also be increasing natural re-emergence of the disease, or increasing recognition of the disease, as more attention is being paid to it. Regardless, an understanding that this disease is a problem in the area is important to allow for prompt diagnosis (and proper treatment), as well as preventive measures.
A vaccine is available, but it is not 100% protective and only protects against certain strains of Leptospira. Nonetheless, it's still a good idea in areas where disease is caused by the strains present in the vaccine and when dogs have a reasonable chance of being exposed.
People can also get leptospirosis. Most often, they are exposed just like dogs: from the outdoor environment. However, pet-to-human transmission has been reported, mainly involving pet rats (since rats are an important reservoir host). People who have contact with an infected dog must take precautions to reduce the risk of transmission. This includes avoiding contact with urine, good attention to personal hygiene (especially hand washing), and proper cleaning and disinfection of any areas potentially contaminated with urine. Prompt diagnosis of canine lepto is very important because treatment rapidly stops the animal from shedding the bacterium. The earlier it's diagnosed, the quicker it can be treated, and the less contamination can occur.
More information about leptospirosis and Leptospira is available on the Worms & Germs Resources page, and in our archives.
Tiger smuggler thwarted
Security screeners at a Thai airport discovered an attempted tiger smuggling, presumably by realizing stuffed animals don't have a skeleton. A 31-year-old Thai national was trying to smuggle a sedated tiger cub in a carry-on bag. As it went through the X-ray machine, screeners noticed an item resembling a real cat. Closer inspection identified the actual item and the individual was arrested.
Unfortunately, this person is presumably among the very small minority of smugglers that actually get caught. Creative smugglers, established smuggling pathways, lucrative markets and extremely lenient penalties combine to make this a pathetic but unfortunately often profitable venture that results in the deaths of huge numbers of animals, and acts as a potential way to transmit various infectious diseases that could affect other animals or humans.
Image: Tiger cub at the Philadelphia Zoo (source: http://commons.wikimedia.org)
Human rabies death in Louisiana
A field worker from Mexico died in Louisiana this weekend from rabies. This is the first case of human rabies in Louisiana in over 60 years, but based on the time the man had been in the country and the incubation period of rabies, it is believed that he was infected in Mexico. Human-to-human transmission of rabies is rare, but healthcare workers and other people he had recent contact with are being evaluated to determine if post-exposure treatment is required. In the case of the man's co-workers, they could have also been exposed to the same source of rabies that infected him.
The original source of infection isn't known, or at least has not been reported. Wildlife are the main source of rabies exposure for people in the US, but dogs are the most common source of human infection internationally. Dog-associated rabies cases in people from Mexico have been previously reported in the US, and it's certainly possible here.
Rabies vaccination requirements
I periodically get questions about whether rabies vaccination is really required or if it's just a good idea. There's not a straight answer because legal requirements vary by region. In Ontario, Regulation 567 of the Protection and Promotion Act states that all dogs and cats three months of age or older that reside in specified areas of the province must be vaccinated. Further, animals must be revaccinated by the date specified on the certificate of immunization. Basically, this means that all dogs and cats must be vaccinated and they must be up-to-date on the vaccination, based on the type of vaccine that was used.
Even if vaccination isn't legally required, if rabies is in an area, it's a good idea because:
- If a pet gets rabies, it will die.
- If a pet gets rabies, owners or other people in contact with it may need post-exposure treatment.
- If a pet gets rabies, it could infect people with this almost invariably fatal disease.
- If an unvaccinated pet gets exposed to rabies, it will need a strict 6-month quarantine or euthanasia. (Euthanasia is common in these situations.) If the pet was vaccinated, all it needs is a 45 day home observation.
Rabies vaccination of pets is easy, cheap and safe, and often required by law.
Image source: http://amcny.wordpress.com
Mass rabies exposure from raccoon
Yet again, a large number of people are undergoing rabies post-exposure treatment because they were exposed to a rabid raccoon that was "adopted" from the wild. In this case, a North Carolina family found a baby raccoon at the side of the road and decided to bring it home. Over the next couple of weeks, various family and friends handled the raccoon, and many were bitten or scratched in the process. The raccoon then died and was identified as being rabid. Forty-five people are now being assessed to determine whether they need to be treated for rabies exposure.
The family dog, which was unvaccinated, has been taken by Animal Control and now faces either a six-month strict quarantine or euthanasia. I suspect the dog will be euthanized.
So, this probably well-meaning but misguided action has resulted in:
- the need for costly post-exposure treatment of many people
- presumably a stressful period for many of those people
- probably the death of the pet dog (although not having the dog vaccinated played a big role here too, since if it was vaccinated, it would only face a 45 day observation period at home, not a strict six-month quarantine or euthanasia).
Fortunately, the raccoon was tested. Otherwise we might be talking about human deaths from rabies, instead of people needing post-exposure treatment. The people who took in the raccoon could also face charges since keeping wildlife without a permit is illegal, but it sounds like that's unlikely to occur.
A few take-home messages from a situation like this:
- Leave wildlife in the wild.
- Vaccinate your pets.
- If you are exposed to an animal that is acting strangely, make sure it's tested for rabies (they did this right, at least).
Toddler risks losing eye to dog parasite...maybe
A few UK news outlets published a story the other day about a toddler with a severe eye infection that was attributed to Toxocara canis, the canine roundworm. Some parts of it didn't make a lot of sense so I held off commenting, but the story's spreading more widely now so I might as well raise a few issues.
The story is about a toddler that fell into a pile of dog feces while playing at the park, then wiped her eye. Her mother took her right home and washed the eye out. Then, according to the BBC:
"She woke up in the early hours screaming and her eye was bright purple and red and swollen shut with the eyelashes inside. She had a temperature and was very lethargic and in a lot of pain." Hospital tests confirmed toxocariasis, which resulted in Amiee contracting optical lobe cellulosis, which can lead to blindness and death if not treated within 72 hours.
Here's where I start to get confused. Eye infections are one problem cause by Toxocara canis. However, the disease (ocular larva migrans) develops when someone ingests infectious T. canis larvae from feces. It takes a few days to a few weeks after being passed in feces before the larvae become infective, so this would have to have been a pile of old feces (something that's certainly possible).
Nonetheless, as I said, ocular larva migrans develops when someone ingests the larvae, which then migrate out of the intestinal tract, journey through the body and end up in the eye. This doesn't happen in a few hours, as is described here. It takes much longer. Even if infective T. canis larvae were injected in the eye, you wouldn't see the type of severe inflammation around the eye that is shown in the picture on the BBC website. Fever is also rarely present with ocular larva migrans. The parasite gradually causes inflammation within the eye, not around it.
The girl is being treated with 3 antibiotics and an eye ointment. Again, this makes no sense for toxocariasis, since it's a parasitic infection within the eye. Antibiotics aren't going to be useful.
The rapidity of onset, the involvement of tissues around the eye, the presence of a fever and the reported treatment suggest to me that this is actually a bacterial infection of the eye and surrounding tissues, something that certainly could be related to the multitude of bacteria present in dog feces.
Regardless of the cause, the notion that dog owners need to be responsible and clean up after their dogs remains. Let's hope the physicians know what's going on and are treating Amiee properly.
What not to do in a vet's office
TheNorthwestern.com has an interesting article about "10 things not to do with pets in a vet's waiting room." They're all good points, and I've put an infectious disease/infection control spin on them below:
1. Don’t fail to contain your cats. Even if your cat is the sweetest thing on record, some other animals may not agree. The last thing we want is to see in our lobbies is an altercation in which one animal dies. Cat carriers are cheap and widely available. Use them.
2. Don’t give dogs free reign. Don’t use retractable leashes!
- You wouldn't (hopefully) go into an emergency room and lick the face of the person puking in the corner or the kid hacking up a lung. Your pet's not as discriminating. Some pets are at the vet because they are sick. You don't want your pet to get what some other pet has. Also, not all dogs and cats are social, especially in a strange environment. You don't want to change your vaccination appointment to a "vaccinate and stitch up the big wound on my dog's face" appointment.
3. Don’t bring in animals you cannot personally control.
- As above. Lack of control equals increased risk to other animals, your animal, and potentially other people.
4. Don’t do the puppy park meet-and-greet thing. The vet’s is not the dog park. It’s a strange environment in which pets don’t always act the way you expect them to. Moreover, in a veterinary hospital the onus is on the doctor’s staff to keep your dogs safe. Please keep all pets apart. After all, no matter how well you know your pet, can you honestly say you know someone else’s?
- Same as above. More mixing and more contact equals a greater risk of disease transmission. That's acceptable in many situations where the risk of coming into contact with an infectious animal is low, but the odds are higher in a place where sick animals congregate.
6. Give the cell phone rest. In a place as potentially anxiety provoking as the vet hospital, cell phones can be a hazard. Even if you don’t feel the anxiety, your pet certainly does. She deserves the comfort of your undivided attention for her safety and her stress level.
- Not really an infectious disease issue but it's annoying.
7. Don’t walk a dog into a packed waiting room. If the lobby is crammed wall to wall with pets, don’t chance it. Ask someone to let the receptionist know you’re waiting outside. Or use your cell phone for something really useful for once.
- Good point. I'd take that a step further. Don't take a potentially infectious pet into a waiting room, packed or not. If you have an animal that might have an infectious disease (e.g. diarrhea, sudden onset of coughing and/or sneezing) it would be ideal to call when you arrive so they can take your pet right back to an exam room or isolation for examination. That way, if your pet is infectious, you won't expose other animals. We're trying to get more clinics to be proactive about doing this, and hopefully your clinic would mention it, but if they don't, feel free to bring it up yourself.
8. Don’t fail to tell the receptionist ahead of time if your pet is severely anxious or aggressive. All hospitals appreciate the warning when you make your appointment. It gives us a chance to offer you back-door alternatives or other concessions to your pet’s unique behavior issues.
- Good point. "If your pet is severely anxious, aggressive or might have an infectious disease" would be better.
9. Don’t bring small children unless you can’t help it. A busy animal hospital is tough on small kids. They’re not old enough to benefit enough from the educational experience relative to their risk of getting hurt.
- Sometimes you have to, but if you can avoid it, that's preferred. Vet clinics can be busy. There are a lot of animals around and it may be hard for a child to resist reaching out for another animal. I haven't seen any data on bites and scratches in waiting rooms, but they certainly occur. As well, if you are distracted by your child, you may not be able to tell your vet all the relevant information or ask all the questions you have.
10. Don’t be rude. Courtesy is king. Kill them with kindness. I shouldn’t have to offer so many versions of the same cliche, but the fact that they all exist is fine testament to their utility.
- Again, not necessarily an infectious disease concern, but really being polite and considerate to those around you applies to just about any situation, and generally makes everyone feel better and makes things go smoother.
Clostridium difficile and hospital visitation dogs
A couple questions that I received about C. difficile and hospital visitation dogs:
Is there any concern about cross contamination from dogs/handlers that visit health facilities and get contaminated by C. difficile? I see on this site a concern about dogs being contaminated by visitation and I wonder if the Delta Society has considered this to be an acceptable risk.
Dogs (and handlers) could be sources of C. difficile in hospitals. We have shown clearly that dogs that visit hospitals are at increased risk of shedding C. difficile in their feces, presumably because they ingest C. difficile spores from the hospital environment and/or patients' hands. All dogs that go into hospitals are at risk, with dogs that lick patients and that are allowed up on beds at increased risk (Lefebvre et al 2009). We have also shown that the dog's body can become contaminated with C. difficile after visiting a hospital.
Should there be a period of time mandated between visits to account for possible contamination?
That's hard to say, but probably not. Contamination is a potential problem and certainly occurs, but we don't know how long it lasts nor whether providing a "rest" period actually does anything. Clostridium difficile spores, the form of the bacterium that would be present on a dog's coat, are very environmentally tolerant and can survive for years. Therefore, giving a few days break in between visitation would not result in the bacteria dying. However, some spores would presumably be physically removed over time, through shedding of hair, grooming and other activities. Based on that, it's plausible that the longer the time between visits, the less likelihood of contamination still being present. Whether this actually helps, we don't know.
What to do?
Among other things, we need to consider whether there is actually any evidence of risk. We don't know whether dogs are able to transmit C. difficile in hospitals. My assumption is that there is some degree of risk, but it's limited and can be controlled with good hygiene and the use of basic visitation practices, as highlighted in the "Guidelines for animal-assisted interventions in healthcare facilities" (American Journal of Infection Control, 2008).
Another thing to consider is whether there are any measures that can be taken to reduce potential risks, while maintaining a practical and effective visitation program. A key component of this is knowing that there are factors that make it more likely that a dog will be exposed to C. difficile during visitation. If a specific subset of dogs is at increased risk, then you have a clearer way to approach it. In this case, dogs that are allowed to lick patients and that are allowed on beds are at increased risk. These activities are modifiable - you can prohibit them without having a significant impact on the visits. Licking can be prohibited. Dogs can be kept off beds unless it is required, and when that's the case, they can be placed on a towel or some other barrier to reduce their exposure to C. difficile from the bed. Additionally, we know that if a dog is being treated with antibiotics, it's more likely to shed C. difficile, so dogs that are being (or have recently been) treated with antibiotics should be excluded from visitation.
For C. difficile to be a problem, it has to go from human or animal feces to a patient's hands and then to a patient's mouth. There are multiple potential interventions to interrupt this chain of transmission. At the end of the day, however, hand hygiene is the key. If people wash their hands before and after touching the dog, there should be much lower risk of disease transmission. A problem is that when I say "hand washing," I mean hand washing - not use of an alcohol-based hand sanitizer. Clostridium difficile spores are resistant to alcohol. That creates a conundrum because the use of alcohol hand sanitizers, a common and recommended hand hygiene method, doesn't have the ability to kill C. difficile. Since not all visitation patients are able to get up and go to a sink, that complicates C. difficile control.
Plague in Saskatchewan
Plague has been identified in a dead prairie dog in Grasslands National Park in Saskatchewan, Canada. This disease, caused by the bacterium Yersinia pestis, circulates in small wild mammals in some regions, and is spread by fleas. While plague is endemic in some parts of North America, it's very rare in Canada. (The last reported human case was in 1939).
Prairie dogs are highly susceptible to plague. The most likely problem with plague occurring in prairie dogs in Grasslands National Park will be the impact on the prairie dog population itself. Outbreaks of plague in prairie dogs can be devastating, virtually wiping out entire colonies.
- Plague can be transmitted to people, but the risk here is quite low. For people to become infected, they have to be bitten by a flea that was infected by biting an infected prairie dog (or other animal). The risk of exposure to a flea infected by wildlife is pretty low if people aren't crawling around prairie dog holes and take some basic precautions.
- The risk to pets is similarly low. Cats are more susceptible to plague than dogs, but they have to be exposed via a flea or, more commonly, from hunting and eating infected wildlife. There presumably aren't too many pet cats in Grasslands National Park, so the risk of exposure is probably limited. Dogs are rather resistant to plague, but they are probably at increased risk of exposure in a situation like this because they are more likely to be taken into areas where infected animals and fleas may be present (e.g. with people going hiking).
The greatest public health and domestic pet concern would be if plague spread beyond prairie dogs and into other small mammal populations that live closer to people or that have more contact with pets. The likelihood of this becoming a major problem is pretty low, but it's a serious disease and this situation certainly needs to be monitored.
In response to this case, park personnel are monitoring prairie dog colonies to look for more cases. They are presumably also keeping a close eye out for any other unexpected deaths of small mammals. Park officials have recommended that people stay away from prairie dog colonies, tuck their pants into their socks (to keep out fleas) and use insect repellent on their shoes. They have also closed some areas to domestic pets.
Photo: Black-tailed Prairie Dogs atop their burrows in Grasslands National Park in Saskatchewan, Canada (source: www.canada-photos.com)
NDM-1, a new threat?
"NDM-1 superbugs" have received a lot of press the last day or two. That's lead to questions about whether there may be any risks for pets.
It's good to see that people are thinking about how this might affect other animal species. That's a thought process that would have been rare a few years ago, and which was probably fostered by the emergence of MRSA in animals.
What it NDM-1?
- NDM-1 stands for New Delhi metallo-beta-lactamase 1. It is a type of beta-lactamase, an enzyme that inactivates certain antibiotics (those of the beta-lactam class). The concern with NDM-1 is that it inactivates carbapenem antibiotics, an important class of drugs that is often used to treat serious and life-threatening infections.
Where is it a problem?
- It's currently mainly a problem in India and Pakistan.
Will is spread to other regions?
- Probably. It's easy for people to travel around the world quickly, and it's easy for new microorganisms to travel with them. A bug that originates in one region can very easily spread across the planet. NDM-1 has been found in a few other countries, including Australia, parts of Europe and Canada. There is concern that the increase in health tourism (traveling to countries like India for cheap and quick procedures like elective surgeries) will result in spread of NDM-1, since people could pick up the bug in hospitals and bring them home. Transmission of NDM-1 in hospitals from patients that had healthcare procedures abroad has been documented in the UK. People traveling to regions where the organism is present for other reasons are also possible sources.
Can it affect pets?
- Probably. Two important types of bacteria, E. coli and Klebsiella spp, can carry NDM-1 (and probably other related bacteria can as well). These can cause infections in many different species. As more people carry bacteria with NDM-1, there's a greater chance that pets will be exposed, as we've clearly seen with MRSA. Dogs that visit human hospitals and pets owned by people who visit India for healthcare are probably at greatest risk, with pets of people who have been hospitalized and pets of healthcare workers likely also at increased risk.
What can we do to reduce the risks?
- Nothing specific. The most important factor here is control of NDM-1 in human hospitals. At the animal level, there's nothing in particular we can do about NDM-1 at the moment. The keys are prudent use of antibiotics (to reduce the likelihood that resistant strains will get established in pets), good general infection control in households and veterinary hospitals (to reduce opportunistic infections by bacteria that can carry NDM-1), and making sure that cultures are taken when infections are present (to find out if/when this becomes a problem).
Pet food/Salmonella outbreak
An article released today in the journal Pediatrics (Behravesh et al, 2010) provides more information about a salmonellosis outbreak linked to pet food. The outbreak itself is old news - I commented about it almost two years ago. What is new is the detailed epidemiological analysis of the outbreak, and there is some interesting information in the paper that is worth reporting. Here are the highlights:
Almost 50% of people who were infected were kids two years of age or younger.
- That's not too surprising considering kids less than five years of age are a high-risk group for getting sick after being exposed to Salmonella.
Households with sick people were almost 7 times as likely to have recently purchased the affected food.
- This provides good evidence of the link between the contaminated food and disease.
The Salmonella strain that was found in people was also found in bags of pet food at the manufacturing plant, samples from the manufacturing plant environment, and fecal samples from dogs that had eaten the food.
- This is pretty convincing evidence that the food was the source. Because they were able to type the Salmonella strain in people and it was an uncommon strain, and they then found the same uncommon strain in food, animals and people, it paints a pretty clear picture of what happened.
Illnesses occurred over a 3 year period.
- This is pretty concerning. This was more than a little lapse at a plant that led to contamination of a single batch of food or a short term event. This was a major failure in quality control that was undetected for a long period of time, resulting in at least 79 human infections in 21 US states.
A cluster of infections caused by the strain involved here, S. Schwarzengrund, was identified early in the outbreak. However, a link with pet food was not considered until the following year.
- That's unfortunate but maybe not surprising. There are a lot of other more likely sources of infection that were probably focused on initially. "What kind of pet food do you feed your dog?" was unlikely to be a routine question asked of people with infections. Identification of outbreaks caused by uncommon events is difficult and typically takes more time.
People that fed their dog in the kitchen were 4 times as likely to have an infection.
- Feeding a pet in the kitchen presumably increased the chance of cross-contamination with human food or contamination of the food preparation environment.
The cause of contamination was never identified. The authors of the paper suspected that contamination occurred after extrusion (the process during which the kibble is formed), which makes the most sense. The extrusion process results in high enough temperatures to kill bacteria like Salmonella. Possible causes of contamination include contaminated equipment used after extrusion, cross-contamination of pre- and post-extrusion food and contamination of substances (e.g. flavour enhancers) sprayed on kibble after extrusion. The fact that Salmonella was found in the room where materials were sprayed on the kibble supports this further.
In general, dry pet food is quite low-risk in terms of Salmonella contamination, but just like with other non-raw-animal products such as lettuce, tomatoes and sprouts, contamination can occur and human infections can result. The best way to reduce the risk is to use good general hygiene practices, particularly washing hands after handling food, keeping pet food and pet food bowls out of kitchens and limiting contact of young children and other high-risk individuals with pet foods.
Plague in Montana cat
A cat from Ennis, Montana, has been identified as the area's first case of plague in a pet cat this summer. Plague is a disease that conjures up images of medieval pandemics and calls of "bring out your dead" (along with calls of "I'm not dead yet" from Monty Python fans).This bacterial disease, caused by Yersinia pestis, is not just of historical interest, however. It is still an important disease in some regions. In the US, it is present in wildlife in parts of the southwestern US and circulates in wild rodents. Domestic pets mainly become infected through eating infected rodents, but the bacterium can also be spread by fleas.
Cats are quite susceptible to plague, and can develop classical bubonic plague, septicemic plague or pneumonic plague, and only about 33% of infected cats survive. Dogs are relatively resistant to the disease.
Transmission of plague from pets to people is uncommon but most often involves cats. Veterinary personnel and pet owners that care for sick cats are at highest risk. While transmission from cats to people is rare, about 20% of people infected from cats die, so it certainly warrants some precautions.
In areas where plague is present, cat owners should consider the following:
- Keep cats indoors to prevent them from hunting and eating rodents.
- Keep rodents and other wildlife out of the house.
- Have a flea control program in place to prevent or treat flea infestations in pets.
- Never catch and keep wildlife (e.g. prairie dogs) as pets.
Salmonella recalls: When to test
The recent run of Salmonella recalls in dry foods, raw foods and supplements has resulted in a lot of questions about when animals should be tested for Salmonella. In general, testing is only indicated in animals that have disease suggestive of salmonellosis. Diarrhea is the main issue, but other problems such as fever, decreased appetite and bloodstream infections can also occur. Clearly, any animal with signs such as these needs to be tested for Salmonella. However, there is no indication to test healthy dogs and cats that have been exposed to recalled products.
Why is that? An important concept in medicine is that you should always have a plan about what to do with the results of diagnostic tests - the result should have an impact on what you do. When you think about what would happen with a negative versus a positive test for Salmonella in a healthy pet, it shows why testing is not useful.
What would I tell you about a negative result?
- I'd say it means the animal is probably negative, but it could be a false negative because of intermittent shedding of Salmonella in stool or a false negative test result.
- I'd also say that even if there was no Salmonella, every animal is shedding multiple potentially harmful pathogens in its stool.
- So, I'd emphasize that if the animal became sick, Salmonella still needs to be considered and that good hygiene measures should be used around the animal (particularly its stool).
What would I say about a positive result?
- I'd say that means the animal was shedding Salmonella at the time the sample was collected, but that doesn't tell us if the animal is still shedding or how long it will do so.
- There's no indication to treat the animal. There is no evidence that treatment of dogs and cats that are shedding Salmonella is needed. There's also no evidence that it's effective. In fact, there are concerns that giving antibiotics could prolong shedding of Salmonella and that it could increase antibiotic resistance.
- Salmonella is certainly a public health concern, but there's not much specific to be done.
- So, I'd emphasize that if the animal became sick, that Salmonella still needs to be considered and that good hygiene measures should be used around the animal (particularly its stool).
Since my recommendations for a positive result and a negative result from a healthy animal would be the same, why test?
E. cuniculi from rabbit to dog?
How likely is E. cuniculi to be trasmitted from an infected rabbit to a dog? My sister has a positive rabbit and my dog was just diagnosed with kidney insufficiency. Now that the dog's kidneys are compromised, should we be concerned?
Encephalitozoon cuniculi is a strange little organism that is now classified as a fungus, but is also similar to some types of protozoal parasites. It is an important (and often overlooked but potentially treatable) cause of neurological disease in rabbits. It is quite common in healthy pet rabbits, and infected rabbits shed the organism mainly in urine.
Less is known about E. cuniculi in dogs. Neurological disease, stunted growth and renal failure are the most common problems that develop. Disease usually occurs in young dogs (less than 1 year of age, with most cases in dogs a couple of months old or younger). Some studies have reported antibodies against the organism in a large percentage of healthy dogs, indicating that they've been exposed at some point, but most studies have found antibodies in few or no dogs.
The risk of transmission from rabbits to dogs is not known. There are a few different types of E. cuniculi, including one type (type I) that is called the "rabbit strain" and another (type III) that is called the "dog strain." The ability of the rabbit strain to infect dogs, particularly dogs with normal immune function, is unclear. Considering the low incidence of infection in dogs (especially older dogs), the different types of E. cuniculi that predominate in dogs and rabbits, and the commonness of kidney disease in dogs, I doubt there's a link between the rabbit's infection and the dog's kidney disease in this case.
Cats and bats and rabies
I had an advice call the other day about two cats that were found with a dead bat. One cat was vaccinated against something (not sure what or when) while the other cat was unvaccinated. This is a situation that, if managed properly, can be very minor, but if handled improperly, can be a major problem, even resulting in death of the animals.
Bats are notorious rabies vectors. The odds of this bat carrying rabies are probably low, but they are not zero and a rabid bat is going to be more easily caught than a healthy bat. Any contact of an animal with wildlife in areas where rabies is present is considered a possible rabies exposure unless proven otherwise. The only way to do this is to have the bat tested.
If the bat is tested and is negative, then everything's fine. If it's positive, then the vaccinated cat would need a rabies booster vaccine and would have to be observed at home for 45 days. The unvaccinated cat would need a strict six month quarantine or would have to be euthanized. So, it's clear that the rabies status of the bat and the vaccination status of the cats are crucial.
Here's what to do in a case like this:
- Get the bat. The bat needs to be tested so you have to maintain control of it. Don't let the cat eat it or run off with it. Don't leave it outside where a person or animal could walk off with it. Put it in a bag or container, without having direct contact with it (e.g. use gloves or a scoop to pick it up). Be very careful if it's not completely obvious that the bat is dead, because an injured bat might look dead but still be able to bite.
- Submit the bat for testing. In Canada, that's done through the Canadian Food Inspection Agency. Make sure they know that an animal has been exposed to the bat. They would not likely test the bat if there was no exposure. They can be contacted directly or through your veterinarian. There is no charge for testing.
- Find out the vaccination status of the cat(s). You need to know when the last rabies vaccine was given and what type of vaccine was used (1 year or 3 year). You need to be able to demonstrate that the pet is current on its rabies vaccination if the bat is positive and you want to avoid the long quarantine.
- Figure out why/how/where the cat(s) caught the bat, and whether that can be avoided in the future.
Another service animal scam
An Ocean City, Maryland man was told that he couldn't take his pet iguana on the Boardwalk because of a town ordinance banning "undomesticated" pets in public places. Instead of accepting the ruling, he "registered" his pet iguana as a "service animal". Protection of true service animals is critical but the very broad nature of the Americans with Disabilities Act (ADA) has let people get away with claiming that their pet is a service animal simply because they want to take their pet places where they are banned. The ADA just "celebrated" its 20th anniversary at the end of last month.
In this case, the owner will not disclose what his disability is or what the iguana does. That's his right according to the Act, and it lets people get away with anything they want. All he's saying is "You know it's like a cat. You put a cat on your lap and you pet it. It makes you feel good. There's a whole range of disabilities that allows you to do this." That's a pet, not a specially trained animal that is being used for a specific and necessary service activity, such as a guide dog.
The company that he's registered the iguana with is a bit of a joke. The first paragraph on their website states:
It's no secret that many businesses simply aren't pet-friendly, even though most of the population is. A large number of our clients register their dogs as Certified Service Animals or Emotional Support Animals (ESAs) not just to accompany them into stores, restaurants, motels, or on airline flights (for no extra cost), but to successfully qualify for housing where pets aren't allowed. Our Service Dog Certification documents formalize and simplify these processes and make qualifying for special housing hassle-free. If you and your service dog become certified with NSAR, both of you are immediately protected under federal law (ADA).
They're not separating service animals from pets. This is a very important distinction - service animals and pets need to be treated differently. Also, the implication that you have register to have a service animal protected is false advertising, presumably aimed at selling more registrations. You don't need to be registered by this group, or any other, to be a service animal.
To "register" your dog with this group, you have to
- Click a box saying you have a disability. (Their list of disabilities requiring service animals is vague and includes things like asthma and diabetes, to conditions for which I have seen no indication that service animals are useful).
- Click a box saying your dog can fulfill most of their required criteria (it actually says dog, not animal. Therefore, I guess this iguana is registered as a dog).
- Then - and this is the most important step - you send them money.
Fortunately, there's light on the horizon. The following clarification of the ADA has been released, and will take effect in early 2011.
Service animal means any dog that is individually trained to do work or perform tasks for the benefit of an individual with a disability, including a physical, sensory, psychiatric, intellectual, or other mental disability. Other species of animals, whether wild or domestic, trained or untrained, are not service animals for the purposes of this definition. The work or tasks performed by a service animal must be directly related to the handler´s disability. Examples of work or tasks include, but are not limited to, assisting individuals who are blind or have low vision with navigation and other tasks, alerting individuals who are deaf or hard of hearing to the presence of people or sounds, providing non-violent protection or rescue work, pulling a wheelchair, assisting an individual during a seizure, alerting individuals to the presence of allergens, retrieving items such as medicine or the telephone, providing physical support and assistance with balance and stability to individuals with mobility disabilities, and helping persons with psychiatric and neurological disabilities by preventing or interrupting impulsive or destructive behaviors. The crime deterrent effects of an animal´s presence and the provision of emotional support, well-being, comfort, or companionship do not constitute work or tasks for the purposes of this definition.
Dog as scalpel...maybe effective but not recommended
What happens when you combine a festering toe wound, a doctor-averse person, a dog and a lot of alcohol. Well, I guess you get Jerry Douthett and his dog Kiko, a Jack Russel who is being called a "lifesaver" for gnawing off Jerry's infected toe.
Apparently Mr. Douthett had what he believed was a small sliver in his toe a few months earlier. He picked away at it for a while, later using a knife to trim away infected tissue. The toe became so inflamed that he couldn't wear shoes. Eventually, he decided to numb the pain and his fear of doctors with a large volume of alcohol. After having 4-5 beers at a local restaurant, he downed two giant margaritas, then passed out after his wife drove him home. His wife explained "Jerry had had all these Margaritas, so I just let him sleep, but then I heard these screams coming from the bedroom, and he was yelling, 'My toe's gone, my toe's gone!'"
Indeed it was, or at least most of it. "The toe was gone," he said. "[Kiko] ate it. I mean, he must have eaten it, because we couldn't find it anywhere else in the house. I look down, there's blood all over, and my toe is gone."
After the Jack Russel relieved Jerry of most of his big toe, Jerry ended up finally going to the hospital. Doctors confirmed that the rest of the toe needed amputation and the infection (which had reached the bone) was probably the result Type II diabetes.They removed the rest of the toe and treated the infection.
Jerry's not upset with his dog. Rather, he's grateful that Kiko's snacking made him go the the doctor, which led to him finally being diagnosed with diabetes which can now be properly managed. The dog is under a 10-day quarantine for rabies observation, as would happen with any dog bite.
People with diabetes are at high risk for various types of infections. I've heard of diabetics with serious foot infections that developed because their pets were licking foot wounds or chewing on their toes. Diabetics can have decreased nerve sensation and sometimes don't notice when their pet is doing damage by licking or chewing.
Diabetes is not a reason to avoid pets, but the increased risk of infection means that extra care needs to be taken to reduce the risk of infections caused by pets, particularly from pets licking wounds directly and from people indirectly spreading bacteria from a pet to a wound. Simple, logical preventative measures around pets and good attention to hygiene are important.
Not drinking yourself into a stupor also helps.
Diagnosing Salmonella
Recent Salmonella recalls have led to some questions about the best way to diagnose salmonellosis in dogs and cats.
The first issue is when to test. In general, there is no indication to test healthy animals. Testing should be reserved for animals with diarrhea or other signs of salmonellosis (e.g. fever).
When testing is indicated, a few things should be considered:
The Sample
- A fresh sample is best. It should be submitted for testing as soon as possible, but it can be kept cool (i.e. refrigeration temperature) for a day or more if it can't be submitted right away. (Do NOT keep a fecal sample in your fridge at home! Take it to your local vet clinic and they will keep it in a designated specimen fridge.)
- More is better. A reasonable volume of stool (e.g. a tablespoon or two) is preferred to something like a rectal swab. Testing can be performed on rectal swabs but they are lower yield because they contain a lot less stool. See image right: standard-size 30 mL fecal sample containers (click for source).
The Test
There are two tests used to detect Salmonella in feces: culture and PCR.
Culture is used to grow and isolate the Salmonella bacterium. Usually, enrichment culture is used, whereby the sample is first cultured in a selective broth culture medium, then put on culture plates. This increases the recovery rate but takes more time.
Advantages of culture are:
- A positive is definitive - the bacterium is definitely there and alive.
- An isolate is available for subsequent testing such as determining the susceptibility to antibiotics and typing it to see what strain is involved.
Disadvantages of culture:
- Salmonella can be hard to grow for labs that don't have a lot of experience and good protocols.
- A few days are required to obtain results, particularly if proper enrichment methods are used.
PCR (polymerase chain reaction) is a molecular diagnostic test that looks for DNA from a particular organism (in this case, Salmonella).
Advantages of PCR:
- Speed. Results may be available within 24 hours.
Disadvantages of PCR:
- Tests validated for dogs and cats are not usually available.
- The test detects both live and dead bacteria, so a positive result could theoretically be from ingestion of dead (and therefore irrelevant) bacteria.
- False negative results can occur from low levels of Salmonella or substances in the stool sample that inhibit the test.
- Lab quality control is critical but not always good.
Current recommendations are to base diagnosis on culture. PCR can be used as a faster presumptive test, but culture should be performed to confirm the diagnosis and get a bacterial isolate that can be further tested for antibiotic sensitivity and typed to see what strain is involved.
Look up before opening your mouth
Recently, Kings of Leon canceled an outdoor concert after a pigeon (with very good aim, apparently) in the rafters above the stage managed to poop on band members, including one shot that hit the face of the band's bassist.
Besides, the "ick-factor," what are the concerns?
Various studies have found potentially nasty microorganisms in pigeon poop, including:
- E. coli
- Various microsporidia
- Various Cryptococcus species
- Multidrug resistant Staphylococcus spp
- Salmonella
- Chlamydophila psittaci
- Mycobacterium avium complex
The risk of disease is pretty low for most people, and we are potentially exposed to many of those bugs on a daily basis. The risks increase with higher ingested doses (so direct-deposit of poop is a much greater concern that inadvertent contamination of your hands) and in people with compromised immune systems. It's unlikely but not impossible that someone would get sick from exposure to pigeon feces, and don't eat poop is a good general philosophy for life.
Peritoneal dialysis and pets
Peritoneal dialysis is used to treat some people with chronic kidney failure. Infection is a major concern, particularly peritonitis (infection of the lining of the abdomen) because peritoneal dialysis involves having an indwelling catheter that goes through the skin and body wall directly into the abdominal cavity.
Infections can occur from bacteria that inadvertently get flushed into the abdomen during dialysis treatment or potentially migrate along the side of the catheter. Accordingly, most infections associated with peritoneal dialysis are caused by bacteria that are found on peoples' skin, such as Staphylococcus aureus.
While the vast majority of peritoneal dialysis infections are human-associated, infections from pets have been reported. Multiple different pet species have been implicated, even hamsters - one case report described an infection in a child that was thought to be caused by a hamster that slept in the same bed as the child (Campos et al 2000).
A recent study in the journal Seminars in Dialysis (Broughton et al 2010) involved a review of the scientific literature for reports of pet-associated peritoneal dialysis infections, as well as a review of records from the authors' peritoneal dialysis unit.
In their review, they identified 124 reported infections caused by zoonotic microorganisms in the literature, involving 12 different microorganisms. The most common microorganisms were Campylobacter, Pasteurella, Zygomycetes, Neisseria, Rhodococcus, Listeria, Mycobacterium avium complex, Capnocytophaga spp, Salmonella, Brucella and Bordetella bronchiseptica. However, only a subset of these were probably associated with pet contact, and retrospectively determining the sources is quite difficult for some. For example, Campylobacter and Salmonella could as easily (or more easily) come from contact with raw meat as from pets. Infections were fatal in 13.5% of cases, demonstrating why this is an important issue.
The most common bacterium causing convincing pet-associated infections was Pasteurella, which can be found in the mouths (and other places) of healthy pets. It is a common cause of pet bite infections and it makes sense that Pasteurella could contaminate pet owners' hands or the dialysis catheter site. In the study of their own hospital's cases, the authors found similar findings, with a low rate of zoonotic infections and a predominance of Pasteurella among those.
Literature reviews aren't a great way of determining the true scope of a problem, because they require people to:
- identify the infection
- identify a pet as a possible source (often the weak link; furthermore, identifying an infection caused by a potentially zoonotic microorganism doesn't necessarily mean a pet was the source)
- decide to write a case report
- get that case report accepted by a journal
Studying medical records has limitations as well, since steps 1 and 2 still need to be performed (with the weak link again being thinking about a pet-association). So, care should be taken when interpreting the results of this study. However, while the results indicate that pet-associated peritoneal dialysis infections do occur, they are probably relatively uncommon.
While pet-associated infections are likely uncommon, any peritoneal infection can be a major problem, so common sense measures that would likely reduce the risk should be used:
- Avoid contact of pets with the dialysis catheter and catheter site
- Wash hands after having any contact with pets
- Don't let pets sleep in the bed
- Wash hands before touching the catheter
Additionally,
- Physicians should be aware of the potential for pet-associated infections, and pet contact by their patients
- If a pet (usually a cat) bites the tubing, this should be reported to a physician ASAP and preventative treatment for infection might be indicated
- Initial antibiotic therapy choices should cover common pet-associated pathogens if there is a history of contact of pets with the catheter or tubing.
People with peritoneal dialysis catheters shouldn't fear their pets, and there is no need for these people to get rid of pets (although they should avoid high-risk pets like reptiles). Pet owners are presumably at somewhat higher risk than non-pet-owners, but the risk appears to be fairly low. In most situations, the positive aspects of pet ownership probably outweigh the risks.
Image: Schematic diagram of peritoneal dialysis (click image for source)
Expanded Iams recall
Following on the heels of a limited recall of feline dry renal diets because of potential contamination with Salmonella, Proctor and Gamble has now recalled all Iams Veterinary Dry Products, as well as Eukanuba Naturally Wild, Eukanuba Pure and Eukanuba Custom Care Sensitive Skin. These products are sold across the US and Canada, and all products with best-before dates between July 1, 2010 and Dec 1, 2010 (so, presumably everything that is on the market at the moment) are included. The broad scope of the recall is apparently a proactive measure based on the premise that since Salmonella was found in some products made at a particular production facility, there is the potential for contamination of everything made there. More data about what they have found and how widespread the contamination is would be nice (but is not forthcoming at the moment).
No illnesses have been reported. If your pet is being fed one of the recalled diets and develops diarrhea, vomiting or other signs of illness (e.g. weakness, fever, decreased appetite), it is important to consider the possibility of Salmonella. Similarly, if any people in the house develop these types of symptoms, they should make sure their physician knows they may have been exposed to Salmonella. Presumably, the level of contamination was low and the risks to the general public (human and canine/feline) are relatively low, with higher risks to people and animals with compromised immune systems or other diseases that limit their ability to fight off a bug like Salmonella.
