Prairie dog flea control

In response to a case of plague in prairie dogs in Saskatchewan's Grasslands National Park, park officials are dusting prairie dog burrows with insecticide to try to control fleas. A single case of plague, a serious bacterial infection caused by Yersinia pestis, was identified in a prairie dog in the park earlier this summer. Plague is present in some areas of North America, but it's rare in Saskatchewan. It circulates in wild small mammals, and prairie dogs are particularly susceptible to infection. The main mode of transmission is via fleas, which feed off infected animals, then bite and infect other animals.

Prairie dog numbers at the park have dropped by 50-70% this summer, however it's not known whether plague is involved in this, as there has also been a drought. It's fair to assume, though, that if there has been one case of plague found in the park, there have probably been many other undiagnosed cases. Whether or not plague is responsible for the large drop in prairie dog numbers, measures to try to reduce plague transmission are a good idea because of the impact it can have on the prairie dog population (and those of other wild mammals), as well as people or pets that may venture into the area. Anyone or anything walking through the area could plausibly be bitten by an infected flea. The odds are probably pretty low, but park officials are trying to keep people and pets out of the park to reduce this risk.

Psst...Wanna vaccinate your dog?

To me, a good general rule is "avoid buying things that are offered for sale at discount prices by a guy in a parking lot." Unfortunately, many people can't seem to pass up a "bargain" and can end up paying more in the end.

A good case in point is a man who was offering rabies vaccination of pets in retail parking lots in southern Oklahoma. James Allen advertised his vaccination "business" on Craig's List and set up shop in various parking lots. He also signed vaccine certificates and listed himself as a veterinary technician. (One problem is that veterinary technicians aren't allowed to sign rabies certificates. Another is that he is not one).  Mr. Allen has yet to be apprehended.

Mr. Allen is suspected of vaccinating hundred of pets with what is, at least from a regulatory standpoint, worthless vaccine. Since the vaccine wasn't administered by a veterinarian, all of those animals are considered unvaccinated. Therefore, if they are exposed to rabies, they face the prospect of euthanasia or a strict six-month quarantine.

Rabies vaccine must be given by a veterinarian in order for government authorities to consider an animal vaccinated in most regions. Mandating that rabies vaccine be administered by a veterinarian isn't a money-grab or veterinarians protecting their turf - it's a government regulation aimed at protecting pets and the public. Restricting rabies vaccination to veterinarians helps ensure that only proper vaccine is used, that the vaccine has been properly handled and administered, and that vaccination is adequately documented. In the absence of clear proof that an animal was properly vaccinated, it has to be considered unvaccinated, because you must err on the side of caution with a deadly disease like rabies.

It's pretty sad that it's so easy to get rabies vaccine in Oklahoma. It should only be available for purchase by veterinarians, but it's apparently easy to obtain from farm and ranch stores. Apparently, stores in Oklahoma can sell the vaccine but are supposed to post a notice saying animals are not  considered vaccinated if it's used. Why you'd allow a store to sell the vaccine when you don't recognize it as effective is beyond me, but that's what's happening.

(click image for source)

Chinese rabies vaccine fraud

Among the most despicable of the recent consumer frauds in China is the sale of counterfeit rabies vaccine. Eight people in south China's Guangxi Zhuang Autonomous Region have been arrested for producing fake vaccine that may have resulted in the death of one child, and threatened 1000 other people.

The fake vaccine was identified during the investigation of the death of a four-year-old child in December 2009. The child was bitten by a rabid dog and received a series of vaccines from a local clinic. Despite the treatment, he died a few weeks later.

There are at least a couple of very serious concerns with counterfeit rabies vaccines:

  1. The use of fake, ineffective rabies vaccine for post-exposure treatment in place of real vaccine could result in deaths that could have otherwise been prevented. Rabies is basically 100% preventable if proper treatment (with an effective vaccine) is administered in a timely manner.  Without this treatment, exposed individuals are at risk of developing clinical rabies, which is basically 100% fatal.
  2. Poorly prepared vaccines could themselves lead to serious adverse reactions, because they may contain any number of contaminants to which the body may react. Contamination of "fake" rabies vaccine with live rabies virus is not out of the question - the use of such a counterfeit contaminated vaccines could actually give a person rabies instead of preventing it.

It's not clear which of the above scenarios may have resulted in the death of the four-year-old boy last year. The child died about three weeks after being bitten by the dog, and had clinical signs of rabies at the time of death. Three weeks is an extremely short incubation period for natural infection, but it's not impossible. Short incubation periods can occur, especially with severe bites to the head or neck (the location of the bite in this case was not reported). However, if the "fake" rabies vaccine used to treat the child was contaminated with live rabies virus (which is possible), then it's not impossible that the boy didn't get rabies from the dog bite, but rather was infected by the contaminated vaccine.

Either way, it's not a good situation. Rabies is a major problem in China, with over 2000 deaths last year alone. The last thing people need is confusion about whether they should be vaccinated and fear that the vaccine might be worse than the bite.

Lyme disease in Australia?

The world is certainly getting "smaller," especially in terms of infectious diseases.  One example is the renewed controversy this month over the existence of Lyme disease in Australia.  A Sydney man was recently diagnosed with the disease following his death, and now a doctor from Laurieton claims to have "absolute proof" of at least two other Australians with the infection.

Lyme disease is caused by infection with one of three species of Borrelia, previously all known as Borrelia burgdorferi.  The disease is transmitted by a few specific species of ticks belonging to the genus Ixodes.  It is relatively common in areas of North America (including some parts of Canada) and Europe where these tick species are also found.  Ticks become infected by feeding on reservoir hosts, which are typically small mammals.  Early signs and symptoms in people following a bite from an infected tick can include a rash, fever, headaches, tiredness and joint pain.  The disease can be very difficult to diagnose because the initial signs are quite non-specific, particularly if the person does not report being bitten by a tick.

None of the tick species known to transmit Lyme disease are found in Australia, although there is one species of Ixodes tick there which some believe is a potential candidate for a vector.  However, after testing some 12 000 of these ticks, evidence of Borrelia infection has still not been found.  Also, none of the known reservoir hosts of Borrelia are said to live in Australia, and no other hosts have been identified.

The Laurieton physician, Dr, Mayne, claims he has "absolute proof" of Lyme disease in at least two of his patients, and says he has about 30 more patients with the disease as well.  "Proof" is a very strong word.  Not only is the disease hard to diagnose clinically, but there is also no perfect test that can detect infection for certain.  Even the DNA test on which Dr. Mayne is hanging his hat can be prone to false-negative and false-positive results.  The article also does not state whether or not the infected patients traveled outside the country and could have potentially picked up the disease in a Lyme-endemic area.  Further investigation is needed before anyone can claim to have "proof."

So why am I writing about this situation on a zoonotic disease blog, when there hasn't even been any mention of pets, and the disease can't be directly transmitted between people and animals anyway?  Because this is a perfect example of a situation in which physicians and veterinarians could potentially work together for the greater good, under the "one health, one medicine" banner.  Dogs in particular can also be affected by Lyme disease.  If the Australians really want to know if Lyme disease has made it to their shores - or perhaps some other tick-borne disease that mimics Lyme - then they shouldn't just be looking in people.  By alerting veterinarians that Lyme disease or a similar condition is cropping up in humans, they can start to look for it in the animal population as well.  If they're left unaware, Australian veterinarians may not consider Borrelia as a potential cause of illness in their patients and therefore not test for it.  If pets also start testing positive for Lyme disease, then hopefully that would be communicated back to the human medical community to increase testing of suspect cases there as well.  If more cases are identified, either human or animal, then further efforts could be taken to identify the tick source and reservoir hosts in Australia.

More information about Lyme disease and ticks in dogs is available in the Worms & Germs archives.

Image: The "classic" bulls-eye rash associated with a tick bite transmitting Lyme disease (source: CDC Public Health Image Library #9874)

Classroom squirrel

A Rosedale, California high school has welcomed a new pet into the classroom: a squirrel. CJ Addington, a physics teacher, caught a baby squirrel that some students spotted outside the school.

I have some (just a few) issues with this:

  • In most areas, catching and keeping wildlife is illegal, for good reason.
  • A baby squirrel wandering around outside is not necessarily an orphan that needs saving. There's a good chance this squirrel will die now that it's been taken from its habitat.
  • I doubt the teacher has a wildlife rehab license and knows how to take care of the squirrel.
  • The teacher wants to "take care of it until it's a full grown squirrel and ready to go back in its habitat." Releasing an animal that has been hand-raised in captivity back into the wild is likely going to result in a quick death, and that's completely unethical.
  • I have a hard time figuring out how to incorporate a pet squirrel into a physics curriculum.
  • The teacher says "The administration did not have any disputes about having the squirrel." The administration, therefore, is clueless about a host of issues, including capture and care of wildlife and CDC recommendations against having wild animals in situations like this.
  • Mr. Addington also said, "It is too young of a squirrel to be carrying anything, so I didn't have to vaccinate it or anything like that." This squirrel could be carrying a wide range of pathogens, including rabies. The number of people that have been exposed to rabies through handling baby wildlife is astounding.
  • "It's cool to have a squirrel that freaks out at random points of class" said one student. That certainly sounds like a healthy, stress-free animal that is thriving in its environment (note the sarcasm here). Also, it shows how it's a potential classroom disruption.

Pets can be useful additions to classrooms in specific and well-controlled situations. Things to consider when deciding if an animal is reasonable to have in a classroom include:

  • Are there any school rules that cover this?
  • Are there any students that are at increased risk of infection because they have compromised immune systems? (Part 2 of that question is "If no, are you SURE that you would know if there was an immunocompromised child in the class?)
  • Are there any students who are afraid of the animal? (Part 2: are you sure? applies here too).
  • Are there any students who might be allergic to the animal? (Part 2 again...)
  • Is there an educational value, or is it just a novelty?
  • Will children eat in the same room as the animal?
  • Can the animal be kept safely and in a humane manner?
  • Who will care for the animal on weekends and holidays?
  • What happens if the animal gets sick?
  • Will protocols be established before the animal arrives, covering the above plus other issues, such as who will have access to the animal, how it will be handled, what type of hygiene practices will be used, etc?

The list goes on. Clearly, having an animal in a classroom is something that requires a lot of thought, time and work. It is possible for animals to be valuable teaching tools in a classroom, as part of the curriculum, as well as providing entertainment and increased empathy towards other species. It's also possible for animals to expose people to serious infectious diseases, to be distracting and to disturb the education of individual students or whole classes.

Wildlife should never be classroom pets.

(click image for source)

Rabies vaccination of kids in the Philippines

The Philippine Information Agency has issued a press release detailing a rabies vaccination program for 5000 public school children in the province of Camiguin. This is prophylactic (preventive) vaccination, not post-exposure treatment.

Routine rabies vaccination is recommended for people at increased risk of exposure. Classically, this involves veterinary personnel, people working with wildlife, people working with strays or feral animals, and similar groups. Routine vaccination of the general public is not used because of the high cost and low need, given the average person's low risk of exposure and the availability of effective post-exposure treatment. By providing vaccine prophylactically, authorities are implying that the rabies exposure risk is quite high for these children.

A Camiguin health office official is reported as saying that the pre-exposure series, consisting of 2 doses, will save money compared to the post-exposure regimen of 4 doses plus a shot of anti-rabies antibody. However, that doesn't make any sense. From a cost standpoint, prophylactically treating everyone with 2 shots only saves money if over half of the population would otherwise need 4 shots. I know rabies is a problem in that area, but certainly half of the kids in the area won't exposed. Further, what really blows a hole in this reasoning is the fact that a vaccinated person who is exposed to rabies should receive a booster series of 2 vaccines regardless, thus bringing the total to 4 shots. People who have been vaccinated don't get the antibody shot if they are exposed, so that does save a little money.  (On a side note, routine vaccination usually involves 3 doses, and the release says people will get two doses but will get vaccinated on days 0, 7 and 21 or 28. That's 3 doses, which makes the math even more questionable). 

If rabies is epidemic in the area, if it's not being controlled well by other means and if there is rampant exposure of children, vaccination may be a reasonable option. However, rabies is basically 100% preventable with proper post-exposure treatment. Rabies deaths are usually because people don't seek, or are not given, proper treatment in a timely fashion. Educating the public to reduce the risk of rabies exposure and to seek medical care, ensuring that there is adequate awareness about rabies among medical personnel and ensuring that adequate vaccine and antibody is available for exposed individuals seems to be a much more logical approach

I was actually wondering whether this press release was real. I did some searching and this agency is an official government agency and a member of the presidential communications group. It would be really nice to see more details about why this decision was made, particularly some of the evidence that was used to determine that this was needed.

It's important to take rabies control seriously. The main problem with rabies in many areas is a lack of effort or adequate resources directed against stray animal control, animal vaccination, public education, medical education and availability of proper treatment. Working on those would seem to me to be a better approach than an expensive and somewhat questionable mass vaccination program of children. The reasoning in the press release is that kids might not report bites, and that is a good point to consider. But, does that actually occur and can it not be controlled by better education?

What's the cost-benefit of rabies vaccination in a situation such as this? It's hard to oppose vaccination of this fatal disease, but are there other ways to provide better overall protection?

Vaccine reactions: Real and imagined.

The other night, my daughter woke up yelling that she was "scratchy." She was quite upset and it continued for a while, despite my best attempts to calm her down. She had a bit of a fever and shortly after broke out in a good case of hives all over her body.

How is this relevant to this blog? Well, earlier that day, she was at the doctor's for her 3-year checkup. She wasn't vaccinated, but Heather made the observation that had she been vaccinated at that appointment, we would have wondered whether this was a vaccine reaction.

Determining whether something is a vaccine reaction can be tough. Too often, people blame a wide range of abnormalities on vaccination, without realizing that they occur at other times too.

The post I wrote a couple of days ago about rabies vaccination mentioned people not vaccinating their horses because of fear of vaccine reactions. I think it's fair to say that there are many more people that think their horse has a problem with vaccines than there are horses that truly have vaccine reactions. Sometimes, people are looking for an excuse not to vaccinate. Often, however, they are really convinced that a vaccine reaction occurred, even though the evidence may be weak.

A good example of this is West Nile virus vaccination. When West Nile virus vaccine first became available, there were rumours that it caused stillborn and deformed foals. There were internet sites reporting cases and publishing pictures of aborted fetuses. However, just because a mare was vaccinated and later aborts, that does not mean that the vaccine caused the problem. Lots of mares that aren't vaccinated have problems. That's why we do research - to see if problems like that are more common in vaccinated horses versus unvaccinated horses. Despite the internet paranoia, there is no evidence that West Nile virus vaccination produces dead or deformed foals, and fortunately this rumour seems to have died down. (I have to wonder how many horses died from West Nile because they weren't vaccinated as a result of this rumour. When some people stopped vaccinating children for measles because of false concerns about autism, there were tremendous increases in measles cases in many areas.)

Vaccine reactions can and do happen. There's no disputing that. Most are mild but some can be severe. However, lots of animals can develop identical-looking of problems at any given time. Just because they were vaccinated recently does not mean that the vaccine caused the problem. A vaccine reaction should be considered when abnormalities develop around the time of vaccination, but automatically blaming the vaccine must be avoided.

Some things to consider:

  • Has the horse had this specific vaccine before? A reaction is probably less likely if the horse has had this specific vaccine multiple times in the past with no problems.
  • Is the problem something that is typically observed with a vaccine reaction? Development of hives after vaccination is pretty suggestive, although it's not definitive. Other problems may be hard to link to vaccination.
  • Was a single or combination vaccine used, or were multiple vaccines given at the same time? If a combination vaccine was used and the potential reaction wasn't severe, giving the specific components of the vaccine individually next time might help determine if it is a vaccine reaction and which component caused the reaction. There's no use stopping all vaccinations if the horse might only be reacting to one specific component. Sometimes, avoiding combinations is all that is needed (although whether that's because it decreases the risk of reactions or whether there wasn't actually a vaccine reaction in the first place is debatable). If there is a problem with one component, then that single component can potentially be skipped but the other vaccines still given.
  • Was it a severe reaction? If not, then not having the vaccine may be a bigger risk than vaccinating. It depends on the disease and the risk of exposure. Also, pre-treatment of the horse with an anti-inflammatory may be enough to prevent a mild reaction or decrease the severity of a more significant reaction.
  • Are there some horses that have severe reactions and can't be vaccinated safely? Yes, but there are very few. Vaccination decisions need to take into account the cost-benefit, in terms of protection and adverse effects. Sometimes, the risks are greater with vaccination, but usually they are not. If you think your horse has a problem with vaccines, work with your veterinarian to determine the best approach. Don't let a knee-jerk reaction automatically prevent you from vaccinating.

Image: A horse with hives along its neck (click image for source)

This Worms & Germs blog entry was originally posted on equIDblog on 16-Sep-10.

Equine rabies vaccination poll's latest reader poll asked the question "If you knew rabies had been found in wildlife in your area, would you vaccinate your horse for it?"

  • 79% of respondents said they already vaccinate against rabies annually.
  • 16.5% said they don't currently vaccinate but would if it was found in wildlife in the area.
  • 4% still wouldn't vaccinate.

The high vaccination rate is very encouraging and is a good sign, considering that rabies, while rare, is 100% fatal in horses and is preventable with early vaccination.

Here are some reader comments (with some additional commentary from me):

Develop a strong immune system instead try to avoid all the drugs

  • Keeping your horse healthy is a good disease prevention measure, but it is not good enough for prevention of rabies. This is a foolish approach to rabies prevention.

Used to yrly. vaccinate in MI, but vets here in KY don't recommend it/My Vet keeps telling me it is not necessary, same with my daughter horses. I disagree.

  • This, and a few other comments about veterinarians not recommending vaccination is very surprising and concerning. Rabies vaccination is considered a "core" vaccine in North America and it makes no sense for veterinarians to be actively discouraging vaccination.

Too many adverse reactions...bad outbreak, might reconsider/There have been too many adverse reactions to the vaccine, I won't take the risk of vaccinating.

  • Adverse reactions can occur with any vaccine, but they are quite rare with rabies vaccine. Sometimes, horses react when they are given a variety of vaccines at the same time, and it might not be rabies vaccine with that caused the problem. Often, the risk of adverse reactions is just used as an excuse not to vaccinate, even if the horse has never had a problem. 

Vaccination is necessary when horses are turned out nearly 24/7

  • Yes. It's also necessary when horses are inside 24/7. Wildlife (especially bats) easily and often get into barns.

I don't vaccinate yearly because I test titers and they remain high for many years.

  • Titre testing is not useful because we don't know what a protective titre is. You can take a titre and get a result, but that doesn't mean the horse is protected. Also, if your horse is exposed, it would be considered unvaccinated by government officials if it had not been recently vaccinated, regardless of titres.

I would be especially diligent to vaccinate if aware of a wildlife outbreak of rabies/I have only vaccinated when there have been cases of rabies, otherwise, I don't.

  • I have a couple of problems with this type of approach. Firstly, you only recognize an outbreak AFTER a large number of animals get sick. Waiting until someone reports an outbreak doesn't help you if your horses are among the first ones affected. Also, rabies isn't a disease that mainly occurs in outbreaks. It is a sporadic disease, where single cases or small numbers of cases pop up all the time. Only worrying about it during an outbreak doesn't help.

I would vaccinate my dogs and cats, but not my horse.

  • Why? If there is a risk of the dogs and cats being exposed, there's a risk of the horse being exposed. (Maybe they like their dogs and cats more!)

I can't buy rabies vaccine only vets can get it so I don't give rabies shots.

  • So, if I can't do it myself (translation, if I can't do it very cheaply), I won't do it. Not a good infection control program.

NEED ANOTHER CHOICE! I run titers. Vac. is indicated every 3-5 years

  • Nope. Vaccination is safe and effective. Standard recommendations are for yearly vaccination. Could we extend that, as is now done with dogs and cats (in which 3 year vaccines are now widely used)? Probably, but we don't have the data to guide us. We can make some reasonable guesses, but do you really want to use a vaccination program designed to protect against a fatal disease to be based on guesses?

The chances of my horses being bit by a rabid critter are slim to none. I don't believe in vaccines

  • I don't think anyone can say that the chance of their horse encountering a rabid critter is slim to none. People encounter rabid critters inside their houses, while walking down the street and in various other situations. I certainly didn't plan on catching a rabid bat in my house, but it happened.
  • Not believing in vaccines is just ignorance. Vaccination is critical for protection against a wide range of diseases. Can adverse reactions occur? Sure, but they are very uncommon (internet rumour mills aren't facts). Do vaccines prevent infections and save lives? Undoubtedly. What happened when people started avoiding MMR vaccines in kids because of now-discredited autism concerns? Lots of people got sick.

Live in UK, no rabies here generally

  • Good reason. Rabies vaccination isn't needed in rabies-free countries.

Fortunately, there were also a lot of logical comments like:

  • I never go without this vaccination. it's way to risky!!!
  • With all the wildlife around, it's not worth risking an unintended encounter causing big problems.
  • Why would you take a chance and not vaccinate...
  • Ever since my uncle's horse died of rabies, I have vaccinated all my horses annually.
  • Are you kidding? Who'd take a chance with rabies?

And as one person so eloquently put it "DUH!"

Apart from the extremely small small number of horses with known and potentially severe reactions to rabies vaccine (not just any vaccine, specifically rabies vaccine), and those living in rabies-free countries, all horses should be vaccinated.

Image: A Little Brown Bat (Myotis lucifugus) roosting under the eaves of a house (click image for source)

This Worms & Germs blog entry was originally posted on equIDblog on 15-Sep-10.

Ohio animal regulations (or lack thereof) under scrutiny

An attack by a bear that killed a caretaker in a Cleveland, Ohio suburb has ignited discussion about the complete lack of regulation of ownership of large and potentially dangerous animals in many jurisdictions. Despite numerous serious injuries and deaths caused by dangerous exotic animals, some places like Ohio have had no means of restricting who keeps such beasts and how. Some places have no rules because no one has put the effort into developing them, while others have had attempts blocked by agricultural interests - people worried about regulations that could affect housing and care of farm animals. (You'd think that, with the number of lawyers in the US, someone could write some legislation that differentiates a Siberian tiger from a cow). As Wayne Pacelle, president of the humane society of the United States, said "It's just a free-for-all in Ohio... Tigers, wolves, bears in a suburban Lorain County community. It's a disaster waiting to happen."

As reported by the Associated Press, "According to a database of publicized exotic-pet escapes and attacks since 1990 kept by the animal rights group Born Free USA, Ohio ranks fifth in the number of episodes that hurt or killed a human — 14. The leader, Florida, has had 43, followed by Texas with 19, New York with 18 and California with 16. Alabama ties Ohio with 14."

Anyway, the bear in question is one of many large exotic animals owned by Sam Mazzola, a "former bear-wrestling entrepreneur." Since the animals weren't in a zoo or some other place where they were publicly exhibited, USDA rules didn't apply. Since the animals were not native endangered or threatened species, US Fish and Wildlife Service rules were avoided. In a place like Ohio, these are the only lines of protection for both these animals and the general public.

Mr. Mazzola claims that injuries and even deaths are "things that happen when you deal and love these type of animals," while explaining that he's had about 2000 stitches from his time working with animals - so much for the claim that this is a safe situation. You also have to wonder about the ethics of putting young people in a position where they are taking care of large and potentially dangerous animals with, presumably, minimal proper training: the person killed in the Ohio bear attack was 24, and people much younger than him have been killed taking care of other large exotic animals.

Large exotic animals can be very interesting, but the health and welfare of these animals, people working with these animals and anyone that might come into contact with them (including if they escape) need to be considered. Too often, large exotic animals are kept in inadequate facilities, in terms of both animal health and welfare and human safety. Since common sense clearly will not prevail, the only way to control this is with legislation clearly describing which animals can be kept by which people and under what conditions, and through diligent enforcement of the regulations (with adequate penalties for violators to act as a deterrent).

(click image for source)

Fatal dog bite

The family of a Washington state man is suing a dog owner after the man was bitten and developed a fatal infection. News reports are somewhat sketchy and contain some inconsistent information, but it appears that Kenneth Bock was bitten by Buddy, a coon hound, at his place of work. There are conflicting stories about how the bite occurred.  Some reports say that the dog was roaming freely, while the owner's lawyer says Mr. Bock was bitten while reaching into the vehicle where Buddy was sitting. Apparently, the dog had bitten someone else at the same business earlier that day, so it's clear this dog and/or its owner had some issues. Regardless, the bite occurred and blood was drawn, but at the time the bite seemed to be minor. However, Mr. Bock developed a severe infection and died a week later.

Buddy was euthanized a few days after the bite.  That in itself is an issue, because any dog that has bitten someone needs to be observed for 10 days to ensure it does not show signs of rabies infection or, if it must be euthanized within 10 days of the bite, the dog needs to be tested for rabies after euthanasia.  Mr. Bock was still alive at the time Buddy was euthanized, so Buddy's rabies status should have been confirmed by observation or testing. Any veterinarian euthanizing an animal is required to ask whether the animal has bitten anyone in the last 10 days.  None of the reports say whether or not the dog was tested.

The news reports also don't provide much information about the infection. They say that the Mr. Bock had another medical condition that put him at increased risk for infection. It could be that he had lost his spleen and he developed an infection with Capnocytophaga canimorsus. This bacterium, which is present in the mouth of most dogs, almost exclusively causes disease in people that have had their spleen removed (as well as alcoholics) and rapidly fatal infections can ensue. There are also a variety of other conditions that affect the immune system and which can thereby put someone at higher risk for various bacterial infections.

Even innocuous-appearing bites can be bad news. People need to protect themselves from bites, and know what to do if a bite occurs.

  • Make sure you know if you are in a high-risk group. If you have a compromised immune system, which includes having had your spleen removed, you need to be aware that you are at particularly high risk for severe complications of any bite. Any high-risk individuals who are bitten should seek prompt medical care.
  • Be careful around dogs. This is particularly true for dogs you don't know, dogs that have a history of being aggressive, and dogs that are in a confined space like a car. They may perceive this as a "den" and interpret someone new near them as an intrusion into their space.
  • Use common sense if you own a dog that has shown ANY tendency to be aggressive. An aggressive, territorial or fearful dog is not a dog to be taking out in public. Any aggressive tendencies must be addressed immediately.
  • Don't take pets to stores. You never know who will be there. There may be people who are very allergic or fearful of dogs. Even if you have the nicest dog on the planet, not everyone wants to be forced to be around it.

(click image for source)

Petting zoo disease prevention

Around here, fall fair season is getting into full swing. Fall fairs can be a lot of fun for kids and adults alike, with midway rides, livestock shows, horse events, lots of good (and bad for you) food... and petting zoos. Petting zoos can be entertaining and educational, but they are also the source of numerous disease outbreaks every year, sometimes resulting in serious illness.

Petting zoos are a concern because even healthy-looking farm animals can be infected with harmful bacteria like E. coli O157 or Salmonella. The odds of getting sick at a petting zoo are low, but there is always some degree of risk. Petting zoos are certainly getting better. I tend to cringe less every year, although it's still not too unusual to see some pretty major issues.

If you are going to go to a petting zoo, think about the following:

  • Kids less than five years of age, the elderly, pregnant women and people with compromised immune systems are at higher risk for infections. Particular care must be taken by these individuals, and they should avoid any contact with high-risk species like baby calves, lambs, reptiles or young poultry (chicks).
  • Take a look at the animals. Avoid contact with any animal that has diarrhea, skin lesions or that appears sick.
  • If you are taking kids into a petting zoo, watch them closely. Make sure they don't put their fingers in their mouths or do anything else that would increase the risk of them swallowing harmful microorganisms. Don't let them carry cups, toys or other personal items that might become contaminated. 
  • Make sure you don't have any food or drink with you when you enter a petting zoo.
  • Above all, wash your hands thoroughly (ideally) or use an alcohol-based hand sanitizer (second best option) after you have had contact with any animal OR been in a petting zoo environment. Even if you didn't touch an animal, you might have contaminated your hands from touching something in the area. In some outbreaks, people that didn't have contact with animals but were in the area have become sick.

By taking these simple steps you can greatly reduce the risks and make it more likely that the petting zoo will be an enjoyable and infection-free event.

At the same time, while it's important to take some responsibility for what we do, petting zoo operators need to ensure that their petting zoos are run properly. If you are at a petting zoo that doesn't comply with expectations, especially if there are problems with access to hand sanitizers or hand washing stations, don't be afraid to contact your local public health department and let them know.

Image source:

Salmonella/salmonellosis...infection/carriage...what does it all mean?

The recent Salmonella recalls and raw food debate have led to a lot of discussion about Salmonella in pets, and also some confusion about what some different terms mean.

Salmonella vs salmonellosis

  • Salmonella is the bacterium.
  • Salmonellosis is disease caused by infection with the Salmonella bacterium.

When an animal is exposed to the Salmonella bacterium from food or feces, a variety of states can develop.

  • No Salmonella, no disease: In these cases, Salmonella does not survive passage through the intestinal tract and nothing happens. The animal doesn't get sick and Salmonella is not detectable.
  • Colonization (also called "carriage"): This is when Salmonella survives passage through the stomach and grows, at least for a while, in the intestinal tract, but does not cause disease. Colonized animals may shed Salmonella, meaning they pass the Salmonella bacterium in their feces, and may therefore be a source of infection for people or other animals. Colonized animals will most often eliminate Salmonella on their own in a short period of time (days to a couple of weeks) and usually don't get sick. It is possible, however, that a colonized animal could develop salmonellosis from Salmonella living in its intestinal tract. This is most likely to occur if something allows the bacterium to overgrow in the intestinal tract or reach the bloodstream, which is most likely in young, old or sick animals.
  • Transient passage: This occurs when live Salmonella that have been ingested survive passage all the way through the intestinal tract, but without the bacterium becoming established in the body and without disease. Salmonella can be detected in feces. It's hard to distinguish transient passage from short-term colonization, and it's not clear whether transient passage really occurs.
  • Enteric salmonellosis: This is the most common form of disease, characterized by diarrhea and potentially varying degrees of depression, weakness, lethargy, decreased appetite and vomiting.
  • Systemic salmonellosis: This uncommon and severe form of disease occurs when Salmonella enters the bloodstream (by invading through the intestinal wall) and causes a bloodstream infection and/or infection of other body sites/organs. This form is often fatal. It is most common in young and old animals, or animals with other diseases that affect their ability to fight infections.
  • Contamination: It is also possible for animals to spread Salmonella that has only contaminated the outside of their bodies. For example, a dog eating contaminated food might get Salmonella on its face. The bacterium doesn't make in to the intestinal tract and can't cause colonization or disease in the dog, but the dog's face could be a source of infection for other individuals for a short period of time, until the bacteria die or are physically removed.

Image: Salmonella sp. on an XLD agar culture plate 24 hours after innoculation. (Source: CDC Public Health Image Library #6619)

Expensive dog poop

It may just be that the Brits write about it more, but it certainly seems that there is a lot more concern and indignation among Brits regarding people who fail to pick up after their pets. Some of their magistrates also seem to share that concern, much to the chagrin of a UK man.

Adrian Davis of Chorley, UK (northeast of Liverpool) was observed failing to pick up feces from his dog while on a walk in a local park.  He claimed that he didn't have any bags to pick up the feces, but the argument didn't work. He was fined 75 pounds and given a bag to clean up the mess.

At this point, the logical approach is to suck it up and pay the fine, and maybe learn something in the process. Ignoring the legal process is never a good idea, as Mr. Davis subsequently found out. Attempts by council to obtain payment were ignored, and he was eventually taken to court. He didn't show up, and ended up with the 75-pound fine, a 150-pound fine for failing to attend, 295 pounds in costs and a 15-pound victim surcharge.

That would have bought a lot of plastic bags.

(click image for source)

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Giardia in London (UK) shelter

A recent paper in the journal Veterinary Parasitology (Upjohn et al 2010) described a study looking at Giardia infections in dogs in a central London shelter. The researchers collected a fecal samples from dogs within 1 day of arrival and tested them for Giardia.

  • 21% of dogs were shedding Giardia on arrival at the shelter.
  • Shedding rates were higher in younger dogs.
  • Of the samples that were genotyped, almost all were Assemblages (types) C and D, the dog-specific types that are not thought to be able to cause disease in people.

This is one more study highlighting a couple of important facts about the protozoal parasite Giardia:

  • Giardia is common and can be found in healthy and diarrheic dogs. Studies of healthy pet populations typically reported lower rates than the 21% found here, but it is not uncommon to find Giardia in approximately 7% of healthy pet dogs.
  • Young dogs are more likely to be infected. That's also true for various other intestinal microorganisms that can cause disease. 
  • The majority of dogs that are shedding Giardia are infected with types that do not infect people. This is an important point and it needs to be considered when people are worried about infections from dogs (or trying to blame pets for human infections). There is limited risk of transmission of Giardia from pets to people. That doesn't, however, mean no risk. Since a small percentage of dogs can shed Giardia types that can infect people, common sense should be used when handling dog feces. Even if a zoonotic strain of Giardia is present in a dog's stool, it has to make it to someone's mouth to have a chance of causing an infection. Proper handling of feces and basic hygiene practices (especially hand hygiene) should greatly reduce the already low risks.

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Pets in the workplace...good or bad?

Pets at work are an often contentious issue. Some people would love to take their pets to work with them to avoid leaving them home alone all day, to save money on doggie daycare, to be able to socialize with their pet during the day, and because they think "everyone will love seeing my dog."

Having pets in a workplace could be a great way to improve employee morale and for some people could be a recruitment tool. It might boost productivity if people are happier and not rushing home because they think their dog's bladder is about to burst (or, more likely, their floor is about to get peed on).

However, it could also be a great way to create strife and legal concerns. Personally, I have no problems walking into a store and seeing a dog or cat wandering around. That being said, I have above-average exposure to animals and am not deathly afraid or allergic. I'm also (currently... hopefully) not highly immunocompromised and at increased risk of an infection from a pet.

No two workplaces are exactly the same. Some businesses might be able to do it right. Some might not. Some might be willing to put the effort into it as a way to boost morale and attract good employees, some might think it's a hassle worth avoiding. If a company allows pets or is thinking of allowing pets in the workplace, they need to consider some important points:

  • Are any people that MIGHT come into contact with the animals fearful or allergic? This is difficult to determine unless you have a small workplace and good communications. People that are allergic or fearful might not voluntarily offer that information because of various reasons, so just saying "if no one raises a concern, everyone's happy" doesn't always work.
  • Will there be any potential contact with the general public? If so, that complicates matters greatly.
  • Are there ways to properly contain and control the pets? Will the pets be allowed to roam free, be kept in the owners office, or be kept in a dedicated kennel area, away from anyone who doesn't want to see them? The more they can be contained, the better. Ideally, there would be a kennel area away from anyone who doesn't want to be in contact with the animals, but close enough that it is easy for owners to check on their pets and take proper care of them.
  • Will having pets there be a disruption to the owner or other employees? A happy workforce is more productive. That's the ideal situation. A workforce distracted by a playful puppy or a cat who loves to flop across your keyboard may not be as efficient.
  • Is there an area where a dog can be safely walked to urinate and defecate?
  • Are there any reasons that having a pet there causes an unacceptable public health concern (e.g. restaurants).
  • Is the business willing to accept the liability issues that come with having animals there? If a pet bites or scratches someone, the business' name will be first and foremost on the lawsuit, I assume.
  • Will the business create a written protocol to address animals in the workplace? This would cover things like where to keep the animal, how to handle it, preventive medicine requirements (e.g. rabies vaccination), when the animal can't come to work (e.g. when it's sick) and other relevant factors.
  • Is there a way to modify the policy over time if something happens? For example, if a new employee is hired and is severely allergic, will the rules be changed? If so, are people notified up front that while they may be able to bring their pets to work now, that can change at any time?

If the workplace can't consider and address all of these areas, then pets are clearly not appropriate. If they can, then there may not be a problem. The key is thinking about these issues in advance, not after:

  • the pet has bitten some who is now upset, threatening to sue and demanding proof of rabies vaccination
  • a person that gets fired claims their poor job performance was because they were afraid of the dog and also afraid of speaking up about it
  • the dog causes a disease outbreak
  • the public health department comes in to investigate an inappropriate situation

Photo credit: James Cheng (source: