Worms and Germs Blog : Animal Health & Diseases : University of Guelph : Ontario Veterinary College : Zoonotic Diseases : Guelph, Hamilton, Ontario

An article in the Winnipeg Free Press by Dr. W. Gifford-Jones, MD, talks about recurrent yeast infections in women. It covers several pertinent points, such as the fact that lots of women who think they have yeast infections actually have different types of infections, and that over the counter treatment might be a concern because of the lack of a proper diagnosis.

Why mention that here? Because of a little anecdote at the end of the story (and one that's gathering the most attention).

'My colleague, faced with repeated failure, decided to ask if his patient had an animal living with her. She replied she did have a small dog and the dog did, in fact, enjoy the comforts of her bed on many occasions. But that was nothing new. It was only after intense probing that she finally admitted with embarrassment to teaching her dog a trick. Since she was away all day at work, she had taught the dog to urinate in the bathtub! The dog had a yeast infection!'

Good for them for thinking about pets. It may have taken time to get there, but at least the question came up. However, this may be yet another example of finally asking the question but stopping the thought process too soon.

Was the pet a possible source of recurrent yeast infection in the person? I can't discount the possibility. We really don't know much about the potential for transmission of this kind of infection, but the pet could have been contaminating the bathtub, leading to subsequent exposure of the person.

Did the pet really have a yeast infection? That's an important question, since they just finished saying a lot of women who think they have a yeast infection don't actually have one. I wonder whether the yeast infection was properly diagnosed by a veterinarian.

Was there any evidence that, if they both had an infection, the same bug was involved? Probably not. However, if you really want to know if the pet is potentially involved, a culture of both the pet and owner to see if the same yeast is present would be needed. Is it really worth doing? Perhaps, because if the pet and person have different yeast, it means that the MD needs to keep looking for possible causes of recurrent infection.

Could the pet have been getting infections from the owner? Possibly. If a pet and person have the same infection, and it's not an infection that classically originates in a pet, then you have to consider the direction of transmission. If the woman had recurrent yeast infections, she could have been regularly contaminating the tub, where the dog could have been exposed when peeing.

It's an interesting case that should raise some questions and hopefully lead to more thought about pets as a potential source of infection in cases like this, but at the same time, a more thorough investigation as well.

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Pasteurella multocida is a bacterium that's commonly found in the mouths of dogs and cats. It's a common cause of cat and dog bite infections in people, but can also be spread through close contact with pets (without bites). It's logical to assume that the closer the contact, the greater the risk of transmission. A recent report in Clinical Infectious Diseases (Myers et al 2012) describes three people with life-threatening Pasteurella infections. A unique aspect was all three people got sick from nursing dying pets.

Case 1

• A 55-year-old woman with sore throat, fever and difficulty swallowing was diagnosed with epiglottitis (inflammation of the epiglottis, a part of the throat region) and hospitalized. Pasteurella multocida was identified on a blood culture.  It was subsequently revealed that she had provided palliative care to her dying dog. As part of this, she was dropper-feeding the dog honey, and also eating honey with the dog from the same dropper.

Case 2

• A 63-year-old woman with sore throat, difficulty swallowing and hoarseness was diagnosed with uvulitis (inflammation of a different part of the throat region) and narrowing of her airway. As with Case 1, P. multocida was isolated from her blood. Her cat had died six weeks earlier and she had "continuously held, caressed, hugged and kissed her cat during its last 7 days of life."

Case 3

• A 66-year-old woman was hospitalized with fever, chills, cough and difficulty breathing. She had severe pneumonia and P. multocida was grown from a sample of respiratory secretions. Two weeks before she got sick, she had provided palliative care for her dying cat, by "holding, hugging, and kissing the head of the cat and allowing the cat to lick her hands and arms."

Fortunately all three women recovered from their infections, but the severity of disease is certainly a concern. As is common, there was no attempt to see whether the implicated pets actually carried the same Pasteurella multocida strain as the owners, but here the authors at least had a good excuse, since all of the pets had died before the owners got sick.

There are some interesting points in the Discussion section of the paper.

"Our 3 patients’ histories of having recently provided palliative pet care to their dying animals were obtained only after P. multocida was identified in cultures and only after subsequent detail-oriented, animal contact histories were obtained."

• Pet contact (or animal contact in general) is still not asked enough by physicians investigating unknown illnesses. It's unclear whether it would have made a difference in these cases, but knowing more and knowing it earlier can help speed the path to the right diagnosis. Here, pet contact was only considered after a pet-associated bacterium was identified.

"Simply asking whether or not the patient had a pet would not have uncovered the defined association of these respiratory illnesses with palliative pet care. The patient with P. multocida uvulitis even denied having a pet (it had died 6 weeks previously) and only admitted to having provided palliative pet care when asked specifically if she had any animal contacts in the past 3 months."

• This shows some of the challenges and how care must be taken when asking about pet contact. Simply asking "Do you have a pet?" doesn't cover it.

"Only diligence and very detail-oriented, pet-related histories will likely uncover further patients with invasive P. multocida infection related to the pet owner’s provision of palliative pet care to dying animals."

• This shouldn't be focused on palliative pet care, since that's a minor component of pet contact. Many other people have close contact with their pets, even when the pets are healthy. It's something that should be considered at all times.

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Although the weather in Southwestern Ontario seems quite confused lately regarding whether it wants to be winter or spring, at least we're still a few months off from having to worry about mosquitoes and the viruses they carry once again.  Warmer parts of the world, however, are in the midst of their mosquito season, and some chickens are lending a hand to give people in the area a "heads up" about what's around.

The Health Department of Western Australia has detected Murray Valley encephalitis virus (MVEV)  in chicken flocks in East Kimberley.  The department has also tested and found the virus in its sentinel chickens in Wyndham and Kununurra.  These sentinel birds play an important role as an early warning system when viruses like MVEV are circulating in the area.  Just like West Nile virus, MVEV typically circulates between birds and the mosquitoes that like to feed on them, but problems occur when the same mosquitoes start to bite people (or other susceptible animals such as horses), particularly when there are a lot of mosquitoes, like when the weather is very wet or when there's been flooding.  Although most people who are infected with MVEV or WNV fight off the virus with no difficulty, or may simply develop short-term, non-specific signs of illness like mild fever and malaise, in some people these viruses can cause severe infection of the brain (encephalitis) and may even be fatal.

Knowing that MVEV has been found in these "guardian" chickens lets people know (via warnings issued by the health department) to take extra precautions against mosquito bites, such as:

• Staying indoors during peak mosquito activity - dusk and dawn
• Wearing protective clothing including long-sleeves and long pants
• Applying insect repellent

In North America, you can pretty much substitute West Nile for Murray Valley in a case like this.  Sentinel chickens have been used to provide early warnings of circulating WNV here, before cases are detected in people or horses.  Another means of early detection that is also used is testing pools of mosquitoes directly.

It just goes to show you can still be an important part of the country's defenses, even if you're a little chicken :p

(click image for source)

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Headshaking is a frustrating problem in horses. It's often hard to identify a cause and treatments are frequently unrewarding. Many different possible causes of headshaking have been proposed, including equine herpesvirus type 1 (EHV-1) infection.

As is common with herpesviruses, EHV can lie dormant in the body, and it may be re-activated during times of stress. There's ample evidence that other herpesviruses can cause nerve pain with reactivation. In humans, re-activation of the varicella-zoster virus (the herpesvirus that causes chickenpox) causes shingles, which is a very painful disorder. Since dormant EHV-1 can be found in nerves in a horse's head, it has been suggested that pain caused by reactivation of dormant virus could be a trigger for headshaking.

A recent study published in the Journal of Veterinary Internal Medicine (Aleman et al 2011) investigates this theory. The researchers looked for the presence of EHV-1 in trigeminal ganglia (a group of nerve "nodes" in the head) in headshaking horses and healthy controls. While it was only a small study, there was no evidence indicating a role of EHV-1 in headshaking, since the virus was only detected in 1/8 headshakers compared to 0/11 controls.

This study doesn't absolutely rule out EHV-1 as a cause a headshaking, since it still could be one of many potential causes that is involved in only a minority of cases. However, this study suggests that EHV-1 is not a particularly common cause of headshaking, if it causes it at all.

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Bob Katter, an Australian Member of Parliament and leader of the Australian Party, has proposed culling flying foxes (fruit bats) as a way to control Hendra virus, which is spread by these large Australian bats. He's not the first person to make such a proposal, but it's a knee-jerk reaction that in reality doesn't make a lot of sense.

It's not completely clear whether Mr. Katter is proposing a plan to completely eradicate the flying foxes altogether, or to simply let people kill any such bats they find on their property, but neither approach is likely to be effective in terms of decreasing the risk of Hendra virus transmission.

If people kill flying foxes on their property, they'll just be replaced in short order by bats from neighbouring areas.

Trying to eradicate the entire species is a bad idea for a variety of reasons:

• Tinkering with a complex ecosystem doesn't often turn out the way you want it to. Australians certainly know from past experiences that bad things can happen when new species are introduced (rabbits are just one example). The same might happen when a species is removed.
• Eradication of the species is probably impossible or at least very difficult. I don't know much about the reproductive rate of flying foxes, but if the species can reproduce at a reasonable rate, they can probably replace the culled animals unless people are really aggressive and seek out all remote breeding sites. The limitations of culling have been clearly shown in rabies control, where it doesn't do much because culled dogs are quickly replaced by new dogs.
• Eradicating flying foxes would be very expensive. What could that money do if put into research on vaccination, treatment, and other worthwhile ventures? What if efforts were focused on eliminating flying fox roosting sites in horse pastures? Overall, the impact would probably be much greater.

Why stop with flying foxes? Australia has lots of nasty critters, ranging from spiders to saltwater crocodiles. Should we kill all of those too? Dog bites kill more people than Hendra every year. Should we kill all dogs?

Hendra virus is not something to ignore. While infections in horses are rare, they are usually fatal and there's the risk of transmission to people. Human infections are very rare but often fatal. So, ways to reduce infection of horses as a means of reducing both human and horse disease are important, but the slaughter of flying foxes doesn't make a lot of sense.

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It's been a while since I wrote about petting zoos. Part of the reason is that the state of petting zoos in this area has improved quite a bit over the past few years, so I haven't been coming home from fairs or other events with a need to vent. However, improvements are not universal, and even with improved conditions, there are always going to be disease risks associated with petting zoos and other events where people have contact with animals.

This week's edition of Morbidity and Mortality Weekly Reports (a rather gruesomely named but very interesting publication by the US CDC) describes a 2011 outbreak of E. coli O157 from a North Carolina State Fair. After receiving reports of infections in four people who had attended the fair, an investigation was launched. Here are the highlights:

• A total of 25 suspected cases were ultimately identified. (Usually, there are many more milder cases that go undiagnosed). Stool samples were collected from 19 of these individuals and the same strain of E. coli O157 was confirmed in 11 of them.
• Affected people ranged from 1-77 years of age.
• Eight people (32%) were hospitalized. Four of those had hemolytic uremic syndrome (HUS), a severe form of disease caused by E. coli O157.
• When compared to people who did not get sick, having visited one of the buildings were sheep, goats and pigs were housed for livestock competitions was the only risk factor identified. While the public was not supposed to have contact with animals in those buildings, 25% of people reported having had direct contact with animals anyway.

An investigation like this often can't determine the source of the pathogen with 100% accuracy, because the investigation occurs after the fact (sometimes long after). That means the animals aren't around anymore for testing, the area/fair may have been cleaned up already, and people may not completely (nor accurately) recall exactly what they did. Regardless, it's quite suspicious that contact with this particular building was the root of the problem. How people became infected isn't clear. Some had direct contact with animals, and that's an obvious potential source. Cattle are the most common source of E. coli O157, but it doesn't appear that any were present in the building. Sheep and goats are a more likely source than pigs. Other people could have been infected through contact with contaminated surfaces in the building, something that has been documented in other outbreaks.

After a large 2004 petting zoo outbreak at this same fair, the state passed a law (named Aedin's Law, after a child who became seriously ill) that set strict requirements for animal exhibits where contact with the public is intended. This facility was not subject to Aedin's Law because animal contact was not intended (even though it was apparently common) and a multiagency task force is looking into additional measures for exhibits where animal contact might occur.

Cost/benefit is an important issue when it comes to infectious disease control. There will always be some risk of disease when interaction with animals is allowed. We can take measures to reduce the risk, but never eliminate it. Therefore, the key is maximizing the benefit and minimizing the risk. Animal contact at fairs and similar events can be very rewarding for some people, so most people will accept some degree of risk. This outbreak involved a relatively small number of people, particularly when you consider approximately 1 million visitors attended the fair. The infection rate was really very, but with a potentially life-threatening disease, it's not something that should be ignored.

As is the case here, infection control is often reactionary, with changes only taking place after problems occur. However, it's good to see that actions are being taken (at least in NC) to reduce the risk of this happening again.

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The executive director of the SPCA of Niagara is under pressure from charges that he's "presided over the killing of hundreds of animals." As is common with shelter controversies, sorting through the emotion and rhetoric is difficult. At best, running a shelter can be a thankless task, due to the overwhelming number of animals, emotion, lack of understanding by the public (and often personnel) of the relevant issues, financial challenges and often poorly designed facilities. At the same time, bad things do happen in shelters, and it's critical to put in the time and effort to determine whether things are being done poorly and what needs to be fixed. Here are some of the issues from the Niagara situation.

"From Oct. 1 to Dec. 15, the local SPCA euthanized 473 cats and 100 dogs, a staggering total of killings, according to sources familiar with the situation at the Lockport Road shelter."

• Apart from the problem of relying on information from anonymous sources, it's hard to put this number into context. You need to know the overall number of animals that come in and the shelter's capacity. It's a sad fact that about 50% of cats are euthanized at most shelters internationally because of massive overload. Shelters shouldn't be cat warehouses. It does no one (including the cats) any good to stockpile huge numbers of cats that never have a chance of adoption, and it creates a perfect environment for disease outbreaks. So, while that number of animals seems high at first glance, it may just reflect the reality of supply and demand, shelter capacity and the health/adoptability status of the animals.
  

"When he was hired, Faso admitted, “My animal care experience is very minimal.”"

• A shelter director doesn't need to be an expert in shelters and animal health. In fact, some excellent shelter directors have come into the job with no experience whatsoever. Their job shouldn't be running animal care. They should be running the shelter, managing personnel, raising funds, liaising with the community and doing a host of other activities. The key is having good veterinary and animal care support, and a willingness to listen to those people. It would be great if every shelter manager was a veterinarian with a shelter medicine residency under his/her belt, along with an MBA and training in communications, but that's not going to happen. Someone with little animal knowledge but the ability to listen and take advice can be an excellent shelter director.

"McAlee and others tell horror stories of animals brought to the shelter for surrender or picked up on the streets and in need of medical care, who are then left to suffer in their cages. In one case, a cat that appeared to be suffering from a broken jaw was brought in and allowed to stay for a week in a cage without treatment. Finally, a concerned staffer took the cat to an emergency veterinary clinic where it was treated and then returned to the shelter."

• That's a big problem. If true, and if this was done because of pressure from the director overriding advice from medical staff, then that's completely inappropriate. Interference with medical decisions and medical care does occur in some shelters and is a major problem.

"When the cat then developed a common respiratory infection, rather than provide further medication for the animal, Faso directed that it be euthanized."

• This is a tougher issue. I hate to see potentially treatable animals euthanized, but euthanasia is an appropriate response in some situations. If they are unable to properly manage an infectious case or are overwhelmed with healthy cats, keeping an infectious cat may pose a huge risk to all of the other cats in the facility. It's impossible to say much here without more details.

"Other sources tell the Gazette that cats at the shelter have been injuring themselves in out-dated display cases and that a donor offered to fund the replacement of those cages. Faso, reportedly, refused to accept the donation."

• Poor housing is a common problem in shelters. Good cages are expensive. It would be bizarre for a shelter manager to turn down money (that came with no strings attached) and if that was done, it would be another sign that Mr. Faso's not right for the job.

"..he has reportedly told board members and others that the local SPCA will “never be a no-kill shelter because it’s too expensive."

• That's an unfortunate fact. No kill shelters just aren't viable in the grand scheme of things. Individual shelters can be no kill, but that's often done by cherry picking the adoptable animals.

It comes down to math. If 50% of cats coming into shelters are euthanized every year because of lack of space, to convert to a no-kill approach we'd need to massively increase shelter capacity every year to accommodate the increasing population. Millions of dollars would be required to create cat warehouses where millions of unadoptable cats lived marginal lives in facility confinement until dying of natural causes or from the massive disease outbreaks that would be certain to happen. I know I'll get reams of emails complaining about this paragraph, but to me it's a simple fact. If you increase supply by 100% per year by not euthanizing any animals, and demand doesn't increase, the math quickly shows you the size of the problem that would be created.

The only way to get to the point where no-kill is a viable approach is to have more responsible pet owners and better animal population control. Euthanasia rates are much, much lower in dogs, in part because of much better population control and also because people tend to try harder to recover lost dogs compared to lost cats. Recovery rates of lost dogs that make it to shelters are very high. Cats... not so much.

So, if you want to help out shelters and the animals in them:

• Spay and neuter your pets.
• Donate to good quality shelters to help them provide optimal care.
• Volunteer, if you have the time and interest.
• Hold shelters to a high standard, but make sure it's a realistic standard.
• Encourage municipalities to properly fund animal shelters and enforcement.
• Consider adopting from a shelter if you are getting a new pet.
• Take the time to learn about the issues, and make assessments based on fact, not just emotion.

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I avoided the "snakes on a plane" title, as ever since the (bad) Samuel L. Jackson movie came out, every reptile smuggling headline seems to use use it. Regardless, would you like to be on a long trans-Atlantic flight with 247 smuggled animals, including a collection of venomous vipers? Probably not.

Fortunately for passengers on a flight from Buenos Aires to Madrid in early December, security screeners took note of the "organic substances moving inside" Karel Abelovsky's baggage. Inside, they found over 200 reptiles and mollusks, including 15 venomous vipers. Among these were two yararas (Bothrops jararaca), a viper that can grow up to 160 cm (~5 ft) in length, and which is a common cause of snakebites in some regions. Two of the animals were dead by the time they were found. Probably many (or most) of the others would have died during transit.

Animal smuggling is a big problem for many reasons:

• It's an major animal welfare issue, since it is reasonable to suspect that only a small minority of smuggled animals survive the process, and even fewer thrive in their new homes.
• Smuggling of endangered species can threaten survival of some species in the wild.
• Smuggling of venomous or otherwise dangerous species can put people at risk. This includes people that purposefully buy dangerous animals but can't handle them, people who buy them not knowing they are dangerous, people at various points of the smuggling process (e.g. security screeners) that might come across the animals, and the general public who can be exposed if the animal escapes.
• Moving animals between regions always carries some risk of bringing along infectious diseases. The less control, the greater the risk.

Mr. Abelovsky has been changed with smuggling and faces up to 10 years in prison, but typically people get off with minimal punishment. Weak enforcement and the potentially lucrative nature of smuggling means that it's going to continue until the problem gets taken more seriously, both in terms of investigation and charging of other people in the process (e.g. where did he get the animals, who was he working with, where were they going to go?) and application of penalties that are severe enough to discourage people.

Unfortunately, while an incident like this gets a lot of attention, it just represents the miniscule minority of smugglers that actually get caught.

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A paper in the journal Orthopedics (Machino et al 2011) describes the case of a 52-year-old man with an infection in the vertebrae of his neck caused by Pasteurella haemolytica. This bacterium (which was renamed Mannheimia haemolytica quite a while ago... I guess their laboratory is a bit behind the times) is most often associated with respiratory disease in cattle. In this case, "because the patient owned 2 dogs and frequently kissed them on the mouth, the cause of infection was thought to be excessive contract with pet dogs."

It's possible, but I have some issues with this.

• Despite the assertion in the paper that this bacterium is a resident in the mouth of dogs and cats, I don't know of much or any evidence supporting this.  A different but related bacterium, Pasteurella multocida, is commonly found in the mouths of healthy dogs and cats, but it's not the one that caused disease here. The authors state that Pasteurella haemolytica can be found in 71-90% of cats and 21-60% of dogs, yet the papers they cite didn't actually find P. haemolytica, they found other Pasteurella.
• The authors also state that the recent increase in pet ownership has caused an increase in P. haeamolytica infections from bite wounds, with absolutely no evidence supporting either an increase in infections caused by this bacterium or any role of pets.
• This paper takes the typical medical journal approach of blaming the pet with no effort whatsoever to find out if the pet was really involved. Would it have killed them to get some oral samples from the dogs for culture, to see if they could actually find the same bacterium?

It's disappointing, but not surprising, to see reports like this. It shows a lack of critical thought about the potential role of pets, a lack of care when writing the report, and a weak peer review process for the journal.

Zoonotic diseases are an important issue. However, we need to focus our efforts on real problems, not bad science. This article is so weak and error-filled that it should be retracted, but it's unlikely anything will happen. I'll write a Letter to the Editor, which, based on my limited previous experience in questioning poor zoonotic disease science in human medical journals, will likely be ignored. Well, we'll see.

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A South Carolina woman has been identified as the first case of human rabies in the state in the past 50 years. Very little information has been released, including whether or not she is still alive. Unfortunately, the odds are quite low that she survived. Successful treatment of a Wisconsin girl in 2004 using a radical new protocol was accompanied by much optimism for treatment of this disease, which at the time was described as invariably fatal. While a few other survivors have been reported, rabies is now often referred to as almost invariably fatal, since the protocol has not been the panacea that it was hoped to be, and death is still the typical outcome.

In the latest case, exposure to a bat in the home a few months earlier was the suspected source of infection. This is a common source of exposure and a typical time frame. Few details are presented, so it's not clear whether the woman was known to have been bitten by the bat or whether that's suspected for some other reason (such as lack of other possible sources).

This is another indication of the care that needs to be taken around bats. While human rabies is fortunately very rare in Canada and the US (it causes tens of thousands of deaths each year worldwide, mainly from dogs in a few developing countries), bats are an important source of exposure. Any encounter with a bat needs to be accompanied by a determination of whether there is a risk of rabies exposure. Anyone bitten by a bat should try to make sure the bat is caught and tested for rabies, because otherwise there's no way to prove it wasn't rabid, and post-exposure treatment would be indicated.

Image: Bat bites can be very dangerous, because they carry the risk of rabies transmission, but they can be so small that they may not even be detected. (Image source: http://agrilife.org/batsinschools/responding-to-a-bat-bite/)

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To each his own, I guess. Today's Toronto Star has an article on the front page of the Life section about the Shine family and their rather close dining relationship with their four cats.

Among some of the highlights:

One of the front page pictures shows one of the cats standing on the counter while food is being prepared.

• Would you want your cat to sit on your food before you ate it? Probably not. Would you lick the cat's feet after it got out of the litter box? Doubt it. By letting the cat sit on the food preparation area, aren't they essentially doing the same thing?

The cats' food and water bowls are on the kitchen counter.

• Feeding pets in the kitchen was a risk factor in a Salmonella outbreak linked to contaminated pet food (Behravesh et al. 2010). That's just feeding them in the kitchen, let alone on the counters.

The other front page picture shows a different cat licking dinner rolls before they are being served. "I'll eat that one" declares the husband, an anesthesiologist (to check out the photo gallery, click here)

• This maybe has a greater "ick factor" for most people, but in reality is probably much lower risk than the first two issues.

Yet another picture (slow news day?) shows a cat stretched out on the dining room table while the rest of the family eats.

As I said above, to each their own. People can make their own decisions about how to interact with animals. It doesn't seem like there are any young children (who are subjected to their parents decisions) to worry about in the household. However, it's unclear whether there might be any other high risk persons in the household to be worried about. Mrs. Shine has diabetes, and that can be associated with effects on the immune system. Further, what about other people that visit the house (or come over for dinner)? Are any of them high-risk individuals, and do they know about the potential risks? Who knows? (The Shine's say they don't have people over for dinner often.)

What's the real risk? It's hard to say. It's probably low but we know:

• people can get infections from cats
• many of the infections that people get from cats are acquired by ingesting microorganisms from these animals
• certain types of pet management (e.g. feeding them in the kitchen) have been associated with higher risk of infection

I'm all for close contact with pets and making them part of the family. If my cat jumps up on the dining room table during the day, I don't panic and try to sterilize it (the table, that is). However, I try to maintain a balance between having my pets as part of the family and not having their microorganisms as part of my family.

There are much worse things that you can do with your pets than are demonstrated here, but I can't believe that it doesn't increase the risk of disease. Maybe for this family, they are willing to accept an increased degree of risk for the benefits they perceive. Unfortunately, I doubt they have really thought about the potential infectious diseases issues or talked to someone about them, to let them make a truly informed decision. (Perhaps (hopefully) their other daughter, who is currently attending vet school overseas, will be able to provide them with some more information on this topic when she gets home!)

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Staphylococcus schleiferi doesn't get much respect. Most of the attention gets paid to Staphylococcus aureus (because MRSA, the methicillin-resistant version, is such a high profile pathogen in humans and it can be transmitted between people and pets) and S. pseudintermedius (because it's a leading cause of infection and MRSP, the methicillin-resistant type, is spreading very quickly and widely in dogs).

Staphylococcus schleiferi is another Staphylococcus species that can cause various infections in dogs, particularly skin and ear infections. It's often overlooked, or more specifically, unnoticed. The problem is it takes some effort to differentiate it from other staph. This species is relatively unique in that it has two distinct subtypes - S. schleiferi coagulans and S. schleiferi schleiferi. The first one is very similar to S. pseudintermedius, and not all diagnostic labs go through the trouble of trying to distinguish one from the other. So there may actually be a lot of S. schleiferi infections that get mistakenly diagnosed as S. pseudintermedius. The second subtype is coagulase-negative (whereas S. pseudintermidius, S. aureus the first subtype of S. schleiferi are all coagulase-positive) and most diagnostic labs don't do any identification of coagulase negative staph. As a result, we only have a superficial understanding of it and its epidemiology.

A recent study from the University of Pennsylvania (Cain et al., J Am Vet Med Assoc 2011) that looked at 225 dogs with S. schleiferi infections has provided some insight into this perhaps not-so-unusual bug. Some highlights:

Ear infections and skin infections accounted for 87% of cases.

• That's expected, since these are very common types of infections for any kind of staph.

Allergic skin disease was the most common underlying disease.

• That's also not surprising. Most staph infections occur secondary to some underlying problem or procedure (e.g. surgery). This shows the importance of taking the time and effort to diagnoses and control allergic skin disease, in order to help prevent infections before they occur.

57% of S. schleiferi  isolates were methicillin-resistant.

• Ugh! I'm not very surprised but it's scary how often we see methicillin-resistance in some staphylococci, because of the complications it can cause with treatment. Methicillin-resistant staph infections can be hard to treat because there may be few effective antimicrobials available.

Methicillin-resistance was more common in the coagulase negative subspecies, S. schleiferi schleiferi.

• It's hard to say whether this means a lot from a clinical standpoint. In generally, coagulase negative staph are much less of a concern than the coagulase positive staph since they are less likely to cause disease. However, we don't really understand the differences between the two S. schleiferi's. If the coagulase-negative version is less able to cause disease, then a lower rate of methicillin resistance in the more concerning coagulase positive type is better than vice versa, but I'm not sure we have enough evidence to say much about this at the moment.

Treatment with a penicillin (e.g. amoxicillin), first generation cephalosporin (e.g. cephalexin) or 3rd generation cephalosporin within the preceding 30 days was associated with having methicillin-resistant S. schleiferi.

• That's not surprising and is one more piece of evidence that "routine" use of antibiotics can contribute to selection for methicillin-resistant staph. It shows how we need to focus on prudent use of antibiotics.

A question I sometimes get is whether an animal with methicillin-resistant S. schleiferi poses a risk to people. We don't really know, but the risk is probably quite limited.

• S. schleiferi coagulans infections in people are extremely rare, so this bug doesn't seem to have much of an affinity for humans.
• S. schleiferi schleiferi infections in people are more common, but it is thought that this subtype is a "human Staphylococcus." Therefore, while it can cause infections in people (usually infections in people that are already sick and/or in hospital), it probably comes from people, not animals.
• So, overall, the risk posed by infected animals is minimal. However, some S. schleiferi can be very drug resistant and you don't really want to have an infection with a multidrug resistant bacterium of any kind ("you're case is very unique" isn't something you want to hear from your doctor), so using good general infection control and hygiene practices around infected dogs makes sense.

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A parvovirus outbreak has been identified at the Occupy San Francisco camp, with at least three dogs affected by the highly contagious and potentially very serious viral disease. The San Francisco SPCA has visited the camp and their temporary clinic was attended by "dozens" of dog owners (indicating lots of dogs at the camp). This is a nice proactive step to help contain the parvo outbreak and hopefully reduce the risk of transmission of various other infectious diseases amongst the animals. Some people appreciated the help. Others (probably the subset that complains about everything) accused the SPCA of spreading bad publicity to help shut down the camp. (I guess they'd rather have good press than healthy dogs.)

In many ways, it's not too surprising. "Occupy" camps are just asking for infectious disease outbreaks, more so in people, but the same risk factors are there for dogs. Whenever you mix together lots of different individuals from different sources, put them in close and prolonged contact and have hygiene challenges, you set the scene for infectious diseases. From a canine parvovirus aspect, heavy fecal contamination from dogs defecating in a small, concentrated area and unvaccinated dogs feed the fire even more. (I don't know for sure that the affected dogs were un- or incompletely-vaccinated, however given the excellent effectiveness of parvovirus vaccines, it's highly likely that sick dogs were not adequately vaccinated.)

Parvo isn't the only infectious disease problem at the camp. Kennel cough (now known as canine infectious respiratory disease complex, CIRDC) has also been identified. This syndrome, caused by a mix of bacteria, viruses and Mycoplasma, has greater potential to spread widely because some of these bugs are highly contagious and vaccination coverage in the population will be lower than for parvo. A large-scale kennel cough outbreak is quite likely if there is kennel cough activity at the camp.

What can you do to reduce the risk, whether it's while "occupying" or during your daily activities?

• Have your puppy vaccinated as per your veterinarian's recommendations.
• Don't take unvaccinated puppies to areas where there will be lots of other dogs. "Unvaccinated" includes puppies who have not had their full initial series of vaccines.
• If your dog is sick, don't take it out in the public, especially to places where other dogs will be present.
• If your dog gets sick during a public event, take it away promptly to reduce the risk of it infecting other dogs.
• Don't let healthy skepticism grow to paranoia, and don't let political squabbles interfere with proper healthcare... both human and veterinary.

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Canine influenza continues its rather puzzling spread through the US. After emerging years ago, it has spread sporadically, causing some large regional outbreaks but sparing many areas, and it has moved about in a pattern that's pretty unusual for a highly contagious virus.

There have been various reports of canine influenza activity in the New York and New Jersey areas over the past few months, and an outbreak has now been reported in a PetSmart doggie daycare in Farmingdale (NY) . Eight dogs have been diagnosed with canine flu (though not sure how or whether it's a lab-confirmed diagnosis) and the PetSmart doggie daycare has been closed since November 14. It was supposed to have re-opened on the 22nd, but dogs that had been there won't be allowed back until two week after their last visit, due to the potential that they were infected at the facility and are still infectious.

Like human influenza in people, canine flu is a viral infection that's readily transmissible between dogs. It typically causes mild disease, with coughing as the main sign, but can cause serious (and sometime fatal) pneumonia in some cases. A vaccine is available but it's not considered a "core" vaccine and is largely reserved for dogs in areas where the virus is active and/or in dogs whose lifestyle makes them more susceptible to exposure (e.g. contact with doggie daycare or boarding facilities, contact with many other dogs, travel to areas where the virus may be active).

Interestingly, PetSmart is paying for treatment of the infected dogs. That's pretty surprising, and may set a precedent they might want to avoid. Infectious diseases are a fact of life. We can do things to reduce the risk of exposure, but we can never completely eliminate the risk that our pets (or ourselves) will get an infection. Usually, infectious diseases that happen in facilities are considered an unfortunate fact of life (especially when it's a vaccine-preventable disease) and facilities rarely cover any costs associated with such outbreaks. In reality, this would be a reasonable approach assuming the facility used standard and reasonable practices to reduce the risk of disease.

If a facility has an infection control plan and adheres to it, whether it's a boarding facility or a veterinary hospital, it's hard to expect them to cover the costs of infections, since not all infections are preventable. In contrast, if there is no infection control program or if things aren't done right, it's easier to assign blame and expect some financial support. Sometimes, costs are covered purely on a public relations basis, which is perfectly reasonable as well. There's no indication why costs are being covered here, but it raises some interesting, broader questions about infection control in facilities like this and their role in covering any costs that are incurred from any type of infectious disease exposure.

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Unfortunately, because of funding challenges (translation... there was no more money), we were no longer able to maintain our equine infectious disease blog (equIDblog) as a separate site. However, based on the positive feedback we had and the amount of traffic on the original site, we still think it serves a role and are dedicated to maintaining equIDblog in some form. So, we are going to merge equIDblog with the Worms & Germs Blog. We have already moved the equIDblog Resources page, which can be accessed through the link in the title bar.  We will also gradually move all of the current archived blog posts from the site and place them under the equIDblog topic category which can be found in the left index bar.  Here we will maintain all of the site's current content and continue to provide information and commentary on equine infectious disease issues. Thanks to all of our loyal equIDblog readers for making the blog such a success, and we hope you'll continue to follow us here on the Worms & Germs Blog!

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A Kitchener, Ontario family is dealing with a household outbreak of ringworm, likely contracted from a new pet guinea pig. Ringworm is a fungal infection cause by a few different types of fungi. Some ringworm fungi are able to infect both people and animals, and those can be spread in households from direct contact with an infected person or pet. In this case, the Gross family purchased a new guinea pig from a local pet store, and unfortunately, ended up bringing ringworm home as a bonus.

As is common, the new pet was the centre of attention when it got home, and the Gross' three children, ages 8, 5, and 2, had very close and frequent contact with it. The next day, the family noticed an area of hair loss on the guinea pig, at which point they took it back to the store. Ringworm was subsequently diagnosed, though there's no mention of how this was done, nor is there any mention of what actually happened to the little critter afterward.

The big problems started a week later, when a red lesion was seen on their youngest child's back. This was also diagnosed as ringworm, though again there's no mention of how, or whether it was definitively confirmed as ringworm. The newspaper report goes on to say "More spots kept appearing on Matthew’s skin as Gross was given different steroid creams to try and contain the infection." You always need to take media descriptions of medical issues with a grain of salt.  Hopefully, the child was treated with anti-fungal cream, not steroid cream, as the latter not only won't treat ringworm, they may make it worse if used alone. Steroid creams are often prescribed for non-specific skin issues (particularly if the skin is very itchy, which can certainly happen with ringworm), but in a case like this where there was known contact with an animal with ringworm, I have to hope that the physician was treating with an antifungal cream instead of, or in addition to, a steroid cream. 

Anyway, whether despite or because of the treatment, more skin lesions kept appearing on the child. Then skin lesions were found on the family dog, and both the dog and cat ended up being treated for ringworm.  The treatment for dogs and cats is relatively straightforward, but it's still a hassle and can be somewhat expensive, and often takes several weeks.

The family has contacted the pet store about paying for cleaning supplies, air purifiers and veterinary bills, but the company did not respond to the newspaper reporter's inquiries, citing an ongoing investigation. It's hard to say whether the company should be held responsible. It largely depends on the measures they take to reduce the risk that they are selling pets at increased risk of transmitting infectious diseases. There's always a chance of picking up something from a pet, so an infection does not necessarily indicate incompetence or liability. If a store had reasonable practices in place, it's probably the purchaser's responsibility to take proper precautions when they take the pet home, and it's an example of why prompt veterinary examination of new pets is always a good idea. It's rarely done, particularly for species that cost less than the price of a veterinary exam, and you never know whether it would have helped prevent anything in this case, but in many instances it can help identify potential issues and address them before problems occur.

Preventing outbreaks like this can be difficult. Ringworm can be found on animals in the absence of any skin disease, so you can't always tell an animal is infected by looking at it. (However, in this case if a large patch of hair loss was noticed by the owners the day after the guinea pig came home, it's likely that something was evident the day before). Ringworm is spread by direct contact, which is common between pets and kids, especially new pets that often get smothered with attention in the first few days. Good hygiene practices, particularly attention to handwashing, can certainly help, but some degree of risk will remain.

Overall, guinea pigs are relatively low risk for zoonotic diseases, but this report shows that even "low risk" pets can be sources of infection. Fortunately, while controlling ringworm outbreaks can take time and be frustrating, it's not a serious disease and it is controllable.

More information about ringworm can be found on the Worms & Germs Resources page.

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Veterinarians at Michigan State University's College of Veterinary Medicine are warning of an upswing in leptospirosis in dogs in the Detroit area. More than 20 cases of leptospirosis have been reported in dogs in the Detroit area, and it's likely that many more unreported cases have occurred. Leptospirosis, a bacterial infection, can cause very serious disease, including potentially fatal renal failure. It can be vague and hard to diagnosis if people aren't thinking about the disease. The most commonly identified problem is kidney disease, and early diagnosis and treatment is critical for successful treatment.

The Leptospira bacterium can survive well in the environment, particularly in moist conditions, and dogs are often exposed through wet environmental areas that have been contaminated with leptospires from the urine of infected wildlife. The strain that has predominated in the latest Michigan cases is Leptospira Icterohemorrhagiae, a type most often associated with rats.

Prevention of leptospirosis involves avoiding exposure to the bacterium as much as possible (largely through avoiding contact with wet areas where lepto cases have been identified) and vaccination. Vaccines are available for dogs and they can reduce the incidence and severity of disease caused by four different lepto types, including Icterohemorrhagiae.  Vaccination should be considered in dogs in regions where lepto cases are identified and in dogs at increased risk of exposure based on lifestyle and travel.

(click image for source)

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One problem with keeping uncommon animal species as pets is that we don't know much about them from an infectious disease standpoint. Some species end up being pretty low risk while others end up causing unexpected infectious disease challenges.

A Texas family found this out the hard way, after their 16-year-old daughter got sick after being bitten by a kinkajou. Kinkajous are strange little critters that are somewhat related to raccoons. Paris Hilton helped fuel the kinkajou fad a few years about after she adopted one (and was bitten by it shortly thereafter). They tend not be be good pets because they are nocturnal and can be antisocial or aggressive during the day (like a lot of people that are kept awake when they want to be asleep).

I wrote earlier this year about concerns regarding the raccoon roundworm, Baylisascaris procyonis, in kinkajous. This more recent report involves an infection that set in after the Texas girl was bitten by her aunt's six-week-old kinkajou. Within 24 hours of being bitten, the girl was severely ill and ended up in hospital for six days. She was treated with antibiotics and responded to treatment.

Because "kinka-what?" was the response to being told that the girl had been bitten, the family and their doctors researched diseases that might be associate with kinkajou exposure. One thing they found was a bacterium called Kingella potus, which was recently found in kinkajous (and subsequently in people with kinkajou bites). Nowhere in the news report does it actually say that this bacterium was identified in the girl, so it's unclear what really happened.

This is yet another example of what can happen when people buy pets that neither they nor the veterinary and medical communities know much about. The recent debacle in Ohio that culminated in the deaths of a large number of exotic animals was a high profile example of the weak to non-existent laws (or enforcement) pertaining to exotic animals in many areas, something that continues to put both animals and people at risk.

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We seem to be seeing more canine papillomavirus cases in dogs in the area as of late. It isn't a high profile disease - the virus doesn't typically make dogs sick, it usually just causes warts.  Whether there is actually an increase in cases or we're simply looking for them more carefully is unclear, but it may genuinely be on the rise.

Canine papillomavirus can cause a range of skin problems in dogs, typically warty lesions (papillomas) that go away over time without specific treatment. Usually, a small to moderate number of warts are found in the mouths of infected dogs (see picture right). Sometimes, the lesions can be large and extensive, causing problems and requiring surgical removal. Most often (like warts in people), it's merely a cosmetic issue that goes away eventually, but it may take months. Depending on the size and extent of the lesions, and whether they are growing or causing problems, treatment may be recommended. This can include crushing a wart to try to stimulate the body's immune response, or topical administration of certain drugs. Complete removal of the lesions surgically should be curative.

Canine papillomavirus is spread by direct contact between an infected dog and a susceptible dog. However, because it tends not to cause severe disease, this virus doesn't get a lot of attention in the research world. However, a recent study (Lange et al J Clin Microbiol 2011) has provided more insight into the virus. In the study, researchers evaluated different ways to identify the virus. They then tested 95 healthy dogs at the University of Zurich and identified viral DNA on the skin or in the mouth of over 50% of the dogs. Whether these healthy dogs pose a risk to others is currently unclear, but it suggests that the virus could be transmitted not only from dogs with skin lesions, but from a large number of normal, healthy dogs. If that's the case, control will be a lot harder, since focusing on just the "sick" dogs (the ones with skin lesions) would miss a big pool of potentially infectious animals.

It's important to note that people cannot be infected with canine papillomavirus, nor can dogs be infected by papillomaviruses from other species.

Image from: www.marvistavet.com

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A couple of days ago, I reported about a deadly outbreak on a Queensland farm that had killed a significant number of horses. A definitive diagnosis has still not been made, but it is starting to look like botulism might be the cause. In my previous assessment, I said botulism was a potential cause of an outbreak like this, but that this particular disease has a pretty consistent clinical presentation so it was probably unlikely if no one was talking about it as a leading option. It looks like now they are, with the owner stating "I've been talking to vets all over Queensland and they're saying the symptoms are spot-on for botulism." It's unclear whether the first vet(s) didn't consider it or whether there wasn't much veterinary involvement at all initially. Regardless, botulism makes sense, particularly with the description of the type of illness that's now being provided.

Botulism testing is underway, but it's often hard to get a positive lab test for this disease in horses. Often, it's a presumptive diagnosis made based on the clinical appearance and lack of any other identifiable cause. Botulism outbreaks on horse farms can be devastating, as in this case. They are often associated with feeding improperly fermented silage or haylage, but there are a variety of ways horses can ingest feed (or water) contaminated with the toxins produced Clostridium botulinum.

The good thing that comes out of this, if botulism is diagnosed, is that there's not much risk to other horses in the region, or at least not any higher risk than is always present. Whenever a large number of horses die from an unknown cause, it's always a concern that a new disease might be involved, something that fortunately does not seem to be likely here.

Image: Poor tongue tone is one of the classic signs of botulism in horses, which results in difficulty eating and drinking (click image for source).

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A recent article in the Toronto Sun described one physician's approach to dealing with dig bites in kids. It contains some useful information, but also a couple of areas that probably require some clarification.

In the article, the physician lays out a few points regarding management of dog bites in kids:

The first thing a parent should do after such a bite is to stop the bleeding by applying pressure. Then, clean the area with warm water and soap. Dogs, like humans, have dirty mouths, so you want to wash and rinse well and even flush out the wound if it's deep.

• "The solution to pollution is dilution" is a old adage. Thorough cleaning is a critical step.

If the bite wound is small, it's usually not sutured, as this might increase the risk of infection. On the other hand, facial wounds and larger bites have to be well cleansed and irrigated, and may require stitches. The sooner this can be done the better.

For a child with a dog bite that has broken the skin, most pediatricians would recommend a seven-day course of an antibiotic, typically Augmentin (unless the child is allergic to penicillin).

• I'm not sure "most" doctors would start a child on antibiotics after any bite that has broken the skin - at least I hope not. Typical recommendations for bites include that antibiotics should be considered with moderate to severe injuries, puncture wounds, people with compromised immune systems and bites over specific areas like joints or the face. Antibiotics for minor soft tissue injuries in otherwise healthy individuals are not typically recommended, although there is some controversy.

Rabies is usually not a risk in dogs that are family pets and live in homes. If the dog is not known or their rabies status is unclear and you can't locate the pet, check with your pediatrician about rabies prophylaxis.

• True. Rabies from pet dogs is very rare in North America. However, if you get it, you almost certainly die, so we take precautions even in low risk situations. So, a little more discussion of this point is important.
• Every dog bite must be approached as a potential rabies exposure. Key points for this are identifying the dog and ensuring it's quarantined for 10 days. After 10 days, if it's healthy, it couldn't have transmitted rabies with the bite. Related to this, any dog bite should be reported to local Public Health personnel. They will ensure that quarantine is imposed if the dog is known, and facilitate rabies post-exposure prophylaxis in the rare situations that it is needed. In Ontario, physicians are bound by law to report bites to Public Health.

Dog bites are unfortunately very common. Usually they are minor and heal without much trouble, but serious or fatal injuries can occur and infections are a potential problem. Knowing what to do in response to a dog bite is important to reduce the risk of a range of complications.

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There are a lot of recommendations out there for establishing or improving sound infection control practices on horse farms, many of which can be found on this very blog.  Some refer to such practices as "biosecurity," but what's done on horse farms compared to the often very strict biosecurity protocols at facilities such as swine or poultry operations (e.g. all-in all-out management, closed barns, shower in) is very different, so we prefer to call it an infection control program, rather than "biosecurity."  Regardless, one of the biggest challenges with regard to infection control, in almost any setting, is getting people to comply with all the various policies and recommendations.  Unfortunately, it's not enough to just tell people what needs to be done (that'd be too easy!) - knowledge by itself usually won't change people's behaviour.  They also need to be motivated to change their behaviour, for example by the potential for a positive reward (e.g. they get to take their horses to shows) or the potential to avoid a negative outcome (e.g. their horses don't get sick).  Furthermore, individuals need to really believe they are capable (physically and mentally) of performing the required tasks - if they don't think they can do it or be effective at it, they're unlikely to try.  In reality, getting people to change their behaviour to adopt sound infection control practices can be quite complex.

A study soon to be published in Preventative Veterinary Medicine (Schemann et al. in press) looked at some of the factors that affect horse owners' biosecurity practices and perceptions.  The study was performed in Australia one year after the devastating equine influenza outbreak that occurred in 2007, using an online questionnaire to which 759 horse owners responded.  Each owner's biosecurity compliance was rated as low (30%), medium (20%) or high (50%) based on how often they reported using 16 different infection control measures.

Factors that were associated with low compliance or poor biosecurity practices included people who:

• were younger in age
• had two or more children
• were not involved with horses commercially
• had no long-term business impact from the 2007 equine flu outbreak
• were not fearful of a future outbreak of equine flu in Australia
• thought their current hygiene and access control practices were not very effective in protecting their horses

Now, studies based on surveys of this kind always need to be taken with a grain of salt, as the study population itself was difficult to define and the information was all self-reported by owners, which can lead to confounding and misclassification bias.  Nonetheless, the results are still interesting and on the whole are consistent with behaviour theory.  Those whose income and livelihood were not dependent on the horse industry, and those who were not fearful of another outbreak, would be less motivated to put the effort into infection control measures.  Furthermore, those who felt that what they were doing already wasn't really effective (for whatever reason) would be less motivated to try harder because they can't see the benefit.  It's quite possible (as the authors speculate) that having two or more children results in less compliance with infection control simply due to the time constraints associated with having kids.  Lack of time to properly perform infection control procedures is a major barrier to compliance, even in human hospitals, particularly with understaffing issues. The lower compliance among young people is also common to studies looking at protective behaviour in human health, possibly because young people have a sense of certain degree of invulnerability that results in riskier behaviour overall.

When it comes to infection control, the old adage "a chain is only as strong as its weakest link" is very important to remember.  Although 50% of the horse owners in this study reported having high biosecurity compliance, the 30% with low compliance could ruin all their efforts should another outbreak occur, by contributing to the transmission and propagation of the disease on their own farms as well as to others.  Hopefully this study will help the horse industry and government identify specific groups (i.e. young people, those not financially dependent on horses) at which educational and motivational campaigns can be targeted in the future.

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An outbreak of canine influenza is occurring in San Antonio, TX, as this virus continues its strange and unpredictable movement through the North American dog population. In an article published on a local San Antonio news website, Dr. Michele Wright, a San Antonio veterinarian, reports 20 confirmed and 70 suspected cases over the past month. It's not clear whether these are all from her clinic, nor is there any information about possible sources of the virus or the severity of disease. Dr. Wright also states that the virus has been identified in Austin and Dallas.

It's not particularly surprising that canine flu has been found in Texas. It's now been identified in at least 38 US states, as well as one Canadian province. An outbreak is not particularly surprising either in this case, because when a virus reaches a new area, it can easily cause widespread disease since it encounters a population of animals that don't have any pre-existing immunity (i.e. antibodies) against it.

What's strange about canine flu is how it has spread across North America. When it was first identified in Florida greyhounds in 2004, it seemed like it was going to spread widely across the dog population. It spread quickly at greyhound tracks and in clusters in Florida and in other states, but it's subsequent spread across the continent was quite patchy - it caused only localized outbreaks in different states, instead of the catastrophic continent-wide epidemic that was anticipated. Whether this relates to the amount and type of direct contact between dogs (e.g. dogs are only infectious for a short period of time and an infected dog has to meet a susceptible dog during that time to continue transmission of the virus, otherwise it dies out), specific aspects of the virus in dogs (e.g. how long it is shed) or lack of recognition of disease in some areas (e.g. mild disease that doesn't get diagnosed) is unclear.

We've been looking for canine flu in Ontario for a few years now, with no "success" (that is, we haven't found it yet).

Are we flu-free at the moment? Probably not. I suspect it's lurking out there, but it's possible that it really hasn't made it to Ontario - yet.

If it's not here now, will it make it here eventually? Almost certainly. It's taking longer than I expected but all it takes is one infected dog entering the country. With the amount of cross-border dog movement, it's probably inevitable.

What about vaccination for canine flu? It comes down to risk of exposure and risk aversion. If flu is in the area, vaccination is a good idea. If flu is in adjacent areas, it's also a good idea. If flu isn't recognized in the area, it's a matter of how much risk people are willing to take and thinking about higher risk situations, as described below.

What about vaccination in Ontario, or other places where the virus doesn't seem to be present? It's hard to say when to recommend canine flu vaccination. Certainly, vaccination of dogs traveling to areas where canine flu is or has been present is a good idea. Vaccination of dogs that engage in high risk activities such as going to shows or kennels is also prudent, since these are the places where we may see the firsts outbreaks if/when canine flu makes it here. Vaccination of low-risk dogs in the province is probably not necessary at the moment (unless people are very risk averse and don't want to take any chances).

Why vaccinate?  It's just "the flu"... This is an attitude that the human public health field battles all the time. Most people who get human influenza (humans can't get the dog version of the virus) feel crappy for a few days and get over it. The perception that it's only and always a mild disease keeps some people from getting vaccinated. However, thousands of people die from flu complications, particularly the very young and elderly individuals. Vaccinating everyone helps reduce the chance that these high-risk people will get sick. Also, while rare, serious (including fatal) infections can occur in otherwise healthy people. In dogs, there's probably actually more indication to vaccinate if there is a realistic risk of exposure. Canine flu can cause classical flu-like disease, akin to the typical human case. However, severe (often fatal) pneumonia can also occur in otherwise healthy dogs. High rates of severe disease were reported initially when canine flu was first identified. It seems like severe disease rates have dropped, but it's still a concern. I wouldn't be surprised if severe disease is more common in dogs with canine flu than in people with human flu.

Whether or not to vaccinate is a discussion dog owners should have with their veterinarian, considering the risk of exposure, risk of severe illness and risk aversion. At the same time, people in areas where flu has not been identified need to be on the lookout for it, to ensure that it gets diagnosed promptly if it emerges, and that information gets communicated to veterinarians and the dog-owning public so that appropriate responses can be made.

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Equine protozoal myeloencephalitis (EPM) is a frustrating disease. It's been referred to as one of the most overdiagnosed, underdiagnosed and misdiagnosed equine diseases - an apt description. In some areas, every horse (particularly every racehorse) that has any real or perceived abnormality (such as not running fast enough) gets treated, usually without any attempt to make a true diagnosis. Most of these animals don't have EPM, but some might, along with horses displaying a range of sometimes vague neurological signs. When an effort is made to really establish a diagnosis, unfortunately it's not straightforward, which leads to more confusion about the disease and how to manage it.

The Animal Health Diagnostic Center at Cornell University have released a document on EPM testing and diagnosis. This document discusses when and why to test, along with important information about the available, recommended tests. It's a nice, comprehensive overview of the subject and worth a look for equine veterinarians as well as horse owners wondering whether their horse may have this enigmatic disease.

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The latest update on equine infecious neurological diseases in Ontario (Eastern equine encephalitis (EEE), West Nile virus (WNV), rabies and neuropathic equine herpevirus type 1 (EHV-1)) is available from the Ontario Ministry of Agriculture, Food and Rural Affairs.

There aren't a lot of surprises, and it's good to see the numbers of cases have remained relatively low. Most notably, there have been three EEE and five WNV cases confirmed, from different regions of the province. This shows that these diseases are still occurring in Ontario horses, albeit at a very low rate.

You always have to consider the limitations of surveillance data like this. To make the list, a horse has to get infected, get sick enough for someone to notice, a veterinarian has to be called and proper samples have to be taken for diagnostic testing. There's certainly no guarantee that this happens in all instances, and it's reasonable to assume that a few more cases of these diseases have occurred in Ontario this year.

In Ontario, August and September tend to be the months of highest activity for EEE and WNV, and as we move into cooler weather (and decreased mosquito activity) the risk of EEE and WNV will start to plummet. I wouldn't be surprised if the numbers increase slightly by the time the final tally is made, but there are no indications that we have major disease activity at the moment.

Surveillance data such as this, including total numbers of cases in the province and an indication of areas where case occur, are important for horse owners and veterinarians to consider when determining their vaccination programs.

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A case report highlighted by TheHorse.com and presented at the ASM/ESCMID MRSA conference in Washington DC last week described a horse-associated methicillin-resistant Staphylococcus aureus (MRSA) infection in Dutch girl.

The girl, a 16-year-old with a severe neuromuscular disease who was wheelchair-bound and on a ventilator, developed an infection following an insect bite. When the infection didn't respond to initial treatment, a sample was taken for culture and MRSA was identified. The girl didn't have any known risk factors for MRSA infection but had had close contact with a foal. The Friesian foal had been at a veterinary hospital prior to the girl's infection. It had a wound infection that was successfully treated with antibiotics, but no culture was taken at the time. The foal was considered a possible source of the MRSA, particularly since the strain that was recovered was ST398, which is widely found in livestock and which is regularly seen in horses in the Netherlands. After the girl's infection was identified, the foal was tested and was also found to be carrying MRSA. The girl's infection was successfully treated and the foal eliminated MRSA carriage without treatment (which is expected in horses because long-term carriage of MRSA seems to be rare to non-existent in this species).

The source of the infection could not be definitively proven, but given the fact that the horse was at a facility that regularly sees MRSA cases, that the strain involved is typically associated with livestock, and that the girl had no other livestock contact, it's a reasonable to assume it came from the foal.

We've known for a few years that MRSA is an issue in horses, and that it can be passed between horses and people - in both directions. Equine veterinarians and horse owners have abnormally high MRSA carriage rates. MRSA carriers are people who have MRSA living in or on them (most often in the nose) without any signs of infection. Most carriers never have a problem, but disease can develop in some situations. The incidence of human MRSA infections transmitted from horses is low, although it's almost certain that many horse-associated MRSA infections are not reported because the link with horses isn't made or people don't mention the horse contact. TheHorse.com article is incorrect in stating that this is only the third case of horse-to-human MRSA infection, since we've already published two such reports, one of which included multiple cases. Regardless, it's an uncommon problem but it is probably also under-recognized. Horse owners shouldn't panic about MRSA, but they should realize that MRSA is circulating in the horse population and that by nature of their frequent and close contact with horses, they are at higher risk for MRSA carriage, and likely also infection.

More information about MRSA in horses can be found on the Worms & Germs Resources - Horses page.

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A huge equine influenza virus outbreak occurred in Australia in 2007 - a classic example of what can happen when a virus gets into an area where it's never been before. There were huge numbers of affected horses and a massive disruption to the industry due to quarantines and other control measures.

A special edition of the Australian Veterinary Journal (July 2011) includes a series of papers covering different aspects of this outbreak. In one paper (Smyth et al) the authors look at the economic consequences and tried to determine the financial costs of the outbreak. Such estimates are always tough to make and can never be 100% accurate, but they can give a general idea of the scope and impact of an outbreak. Not surprisingly, the costs were pretty astounding.

Australian Government

A series of measures were implemented to assist individuals and organization that were impacted. The total cost of those packages was over $263 million AusD.

State/Territory Governments

New South Wales and Queensland were most seriously affected, but all states and territories were impacted. These governments provided support in addition to the federal funds. For example, Queensland allocated over $27 million to various efforts, while New South Wales contributed more than $46 million.

Racing and Wagering Western Australia

This is the government body that regulates racing in Western Australia. The outbreak cost this agency around $500 000, a figure that does not include lost employee time and approximately $15 million in lost wagering revenue. Some of this was recovered through insurance, but it's now unlikely that they will be able to get further insurance to cover outbreaks.

Harness Racing Industry

It's always hard to figure out the true costs to an industry after a major disaster because the trickle down effect goes so far, affecting people who provide support and services (e.g. hay suppliers) to various businesses that are affected directly because people in those groups don't have money to spend. The total identifiable costs were calculated to be over $23 million, about half of which was to owners and trainers. The authors acknowledge the true costs were probably much higher.

Inquiry

A large inquiry was commissioned after the outbreak. This cost over $5 million.

Animal Health Australia

This group coordinated the emergency response and had to divert tremendous personnel time and resources. This included the vaccination program that distributed 670 000 doses of vaccine.

Households and businesses

Overall, it was estimated that horse associations lost $281 million, horse businesses $65 million and households $34 million.

Horse deaths

The value of horses that were reported to have died was close to $1 million, despite the fact that equine flu is uncommonly fatal. This number doesn't include intangible costs associated with losing a horse. However, reported deaths may be a minority and it was estimated that true horse death costs may have been $44 million. (However, I suspect the death rate estimate used for this value is high.)

Veterinary treatment

Estimated costs...$35.7 million.

Do the exact numbers matter? No. They simply show that an infectious disease outbreak can cost a lot. In many areas, horses receive little government attention because they are not food animals, despite the fact that the highly mobile horse population is probably at much higher risk of importing a new disease, and despite the fact that the economic impact of the industry is huge (and often overlooked by governments and groups that fund agricultural research).

If nothing else, this should serve as a reminder to government and industry groups that attention needs to be paid to infection control and emergency planning. While groups are often reluctant to put  much or any time, effort and funds into these areas, the amount of money that would be spent is inconsequential compared to the potential impact of even a small outbreak.

Image source: www.dailyclipart.net

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The latest edition of Emerging Infectious Diseases (Berger et al 2011) describes a case of Corynebacterium ulcerans infection in a women that was likely acquired from her cat.

Corynebacterium ulcerans is a bacterium that's related to C. diphtheriae, the cause of diphtheria. Some strains of C. ulcerans can produce toxins that cause diphtheria-like disease, and with the success of diphtheria vaccination, C. ulcerans is now the leading cause of diphtheria-like disease in people in some regions. Typically, C. ulcerans infections are associated with ingestion of contaminated milk or dairy products, but reports of infections acquired from dogs and cats appear to be on the rise. As is often the case, whether this is because it's becoming more common or that people are simply looking more is unclear.

In this report, a woman from Germany developed diphtheria-like disease, including a sore throat, ear ache, hoarseness and nasal obstruction. A swab was taken from her nose and throat, and toxigenic C. ulcerans was isolated. She didn't report any livestock contact and had not traveled abroad, so other possible sources of infection were considered, particularly other types of animal contact. She had a cat, so nose and throat swabs were collected from her pet, and the same strain of C. ulcerans was isolated.

With this type of investigation, you can't prove that the cat gave the bug to the owner. Since the cat was healthy and tested after the owner was sick, you can't say for sure whether the cat was the original source or if it was infected by the owner. However, with a bug like C. ulcerans that has been associated with pets before and that can be carried by healthy cats, the conclusion that it came from the cat is reasonable. The cat was treated with antibiotics and C. ulcerans was not detected after treatment.

This is an interesting report.  It's always good to see people thinking about the relationship between human and animal disease, but at the same time, it's important to put this into context. Yes, C. ulcerans is a potential zoonotic concern, but it's rare. Anytime you see a case report involving a single person in the medical literature, you know it's either something new or very rare. In this case, it's the latter, since we know from previous reports that this bug can cause human infection and be transmitted from animals. Rare doesn't mean never, and you can't dismiss it, but C. ulcerans is just one of many bacteria that can be found in cats and transmitted to people. It's part of the inherent risk of infection that comes with cat ownership. This relatively low risk is hopefully outweighed by the benefits of cat ownership, and the cost-benefit can be maximized by basic infection control and hygiene practices. This report also shows how it's important for physicians to query pet ownership when dealing with infectious diseases in their patients, something that still needs lots of improvement.

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A paper in the Journal of Neurooncology (Redelman-Sidi et al, 2011) describes "kitten-transmitted Bordetella bronchiseptica infection" in a cancer patient. The patient in question had a brain tumour that was surgically removed. The 56-year-old man was then started on chemotherapy, which in addition to killing cancer cells can also cause significant impairment of the immune system, which puts chemotherapy patients at high risk for infections of many kinds. This particular patient developed a persistent cough during treatment and was eventually diagnosed with B. bronchiseptica infection. This bacterium is one of the causes of kennel cough in dogs, and can cause respiratory infections in other species, including cats.

The man had acquired a kitten three weeks before he developed the cough. The kitten had (at some undefined time) conjuncitivitis and signs of respiratory disease. Unfortunately, as is too often the case in reports of supposed pet-associated disease in the medical literature, the kitten was not actually tested.  Bordetella bronchiseptica is classically an animal-associated organism, the kitten was newly acquired and it had respiratory disease.  These factors strongly suggests the kitten was the source.  However, without testing of the kitten and investigation of other potential sources of infection, it's hard to be as definitive as the title suggests. The suspicion of the kitten being the origin is reasonable nonetheless.

Some statements from this report are contrary to my typical recommendations for pets and immunocompromised individuals.

Getting a young animal

• Kittens and puppies are entertaining, but they are also higher-risk animals compared to adult dogs and cats. They are more likely to harbour a variety of infectious agents. They are also more likely to bite or scratch through playful or rambunctious behaviour, and it's harder to properly assess their temperament. If an immunocompromised person wants to get a new pet, getting an mature animal is ideal.

Source of the kitten

• The paper unfortunately doesn't mention from where the kitten was obtained and whether there was a respiratory disease problem in other animals at the source. Animals in shelters, humane societies and pet stores are more likely to carry various infectious diseases because they are densely populated facilities, often have infection control challenges, house many high-risk animals and are stressful environments. Getting new animals from these places is not ideal for a high-risk person.

Veterinary care

• The kitten had signs of respiratory disease and was seen be a veterinarian. It doesn't appear that any testing was done and the kitten was just treated with antibiotics. That's pretty common, but in a situation where there is a high-risk person in the house, it's wise to be more aggressive with diagnostic testing to determine whether there may be any concerns for the person.

A pet can be a wonderful thing for a person living cancer, by providing social and emotional support, along with other benefits. Pet ownership always carries some risk of zoonotic infections, and the risk is higher in people with compromised immune systems. Rarely, if ever, is pet ownership inappropriate for a cancer patient, although certain pets and certain situations might be, and high-risk individuals need to think about possible risks and measures to reduce those risks.

People with cancer or other problems affecting their immune system should ensure that their physician knows that they own pets. Veterinarians need to play a role as a member of the overall healthcare team too. Optimizing pet health can help reduce the risk of human infection. Prompt and proper diagnostic testing can identify potential issues. Proper counseling can reduce risky situations from inappropriate pets, inappropriate contacts and other factors that might make exposure to a nasty infection from a pet more likely.

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A recent case of canine rabies in France showed yet again the risks posed by illegal importation of animals. This case is somewhat unusual since it seems to involve ignorance of the rules and lax enforcement, compared to rampant animal smuggling, but the end result was the same.

The animal in question was a puppy that was brought to France by a family that had been vacationing in Morocco. They found the puppy on July 11 and returned to France on July 31. European Union regulations require that imported dogs be vaccinated against rabies and microchipped. Neither was done to this puppy, and it was in fact too young to vaccinate against rabies according to standard protocols. The family traveled back to France by ferry and car, and either met no customs officials or at least no officials who asked any questions about the puppy.

They day after they returned to France, the puppy started to exhibit behavioural changes and progressive sleepiness, with subsequent development of aggression. Five days later, it was taken to a veterinarian and it died the next day. Rabies was confirmed a few days later, and testing of the virus strain indicated that it was of the Africa-1 lineage and closely related to strains previously isolated in Morocco.

An investigation into possible rabies exposure ensued. Typically, it is assumed that animals can be infectious for up to 10 days prior to showing signs of rabies. Often, this is extended by several days for added confidence and because it's not always possible to determine exactly when the earliest, mildest signs might have developed. In this case, they considered the period that rabies could have been transmitted to be from July 18 until the puppy's death.

Multiple people had close contact with the puppy. Three family members had been bitten, a clear indication for post-exposure treatment. One other person (a friend of the family, it appears) was also bitten and received treatment. Another person reported being licked on non-intact skin (i.e. an area of skin with a cut, abrasion or other break in the normal barrier) and was also treated. The attending veterinarian, who had been previously vaccinated, received two booster shots.

This isn't the first time that rabies has made its way from Morocco to France, and it's concerning that it was so easy for it to happen. Nine rabid dogs have been illegally imported to France from Morocco since 2001. In 2008, one such dog subsequently transmitted rabies to several other dogs, resulting in France losing its rabies-free status until February 2010. It's not surprising that no questions were asked of the family traveling from Spain to France because of the open nature of borders between EU countries, but the ability to enter Spain from Morocco with no flags being raised is a concern. Hopefully there's an investigation into how this puppy was able to get into Europe so easily and how to reduce the chances of this happening again.

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A paper that will be published in the September edition of Emerging Infectious Diseases (Mead et al 2011) talks about the potential for dogs to act as indicators of Lyme disease activity and risk for people. The use of animals as sentinels for human disease is well established. Sometimes it's because animals are more readily affected. Sometimes it's because the disease is easier to diagnose in animals. Sometimes it's because getting access to samples from animals is easier than from humans.

Because of the distribution of ticks that transmit the causative bacterium (Borrelia burgdorferi) and wildlife that act as the reservoir, the occurrence of Lyme disease is highly variable geographically. Knowing the amount of Lyme disease activity in a specific region is important for understanding the role of this disease in humans, and for implementing preventive measures.

Like people, dogs can get Lyme disease. Dogs are NOT sources of human infection, but since both dogs and people get Lyme disease the same way (from Ixodes ticks), infections in dogs can indicate the potential for infections in people (and vice versa). Since dogs may be more prone to being exposed to ticks, and since ticks are most likely to stay on dogs for the 24 hours or so that is required for ticks to transmit the bacterium, dogs may be more likely to be exposed to Borrelia spp. in endemic regions.

That's the reasoning in the Mead paper which suggests that dogs, because of their potentially greater chance of exposure and tendency to produce a good immune response after exposure, might be good indicators of human Lyme disease risk. To examine this premise, the authors compared data about B. burgdorferi antibody levels in dogs to human infection data. (Note: These are two different things: In dogs, they looked at antibodies, which indicate exposure but not necessarily disease. In people, they looked at disease. It's not inappropriate to compare the two, but you have to be aware of what they were comparing).

Overall, they showed (not surprisingly) that there was a relationship between antibody levels in dogs and Lyme disease in people. Some key findings were:

When the percentage of dogs with antibodies against B. burgdorferi was <1%, there were extremely low rates of disease in people in the area.

• This makes sense since it would indicate that there's little or no transmission occurring in the area. Low levels of B. burgdorferi in dogs or people don't necessarily indicate that Lyme disease is active in the area, since some cases could have been acquired during travel, and false positive results are possible with current testing.

The risk of disease is generally low to non-existent outside the highly Lyme-disease endemic areas: Northeast, mid-Atlantic and upper Midwest regions of the US.

• These are the areas where ticks capable of spreading the bacterium are common and where the bacterium is resident in wildlife, so that's not surprising.

Where 5% of more dogs had B. burgdorferi antibodies in their blood, there was always an above-average incidence of Lyme disease in people in the state, with a lesser association at the county level.

• Again, this makes sense. If most dogs are exposed, more people are going to be exposed, and more people will develop disease.

In 15% of counties where dogs had a >5% rate of antibodies, people did not have above average disease rates. However, in half of them, the incidence of disease in people increased to above average in the following 3 years.

• This is quite interesting and perhaps the most important finding of this study. It suggests that monitoring rates in dogs may predict trends in people.
  

What does this all mean? Well, a lot of these results would be expected based on what we know about Lyme disease. However, the apparent close linkage between human disease rates and dog antibody rates, and particularly the potential that dog rates could predict human rates, is intriguing and could be useful. By routinely monitoring for antibodies in dogs, areas where Lyme disease might be on the rise or might be emerging in people could be identified, leading to more focused educational efforts directed at both the public and healthcare personnel. Getting the dog data (or at least getting good dog data) is perhaps the problem, since testing would need to be done on a subset of the dog population that's not biased and is of adequate size to say something useful. There are ways to do this, but it takes time and money to do it right. Taking advantage of blood samples collected for heartworm testing is one possible approach, but careful thought needs to go into what could be done and whether it would be better than more intensive surveillance of humans or ticks.

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A recent paper about toxoplasmosis in the journal Biology Letters (Thomas et al. 2011) has attracted a lot of attention because it reports a possible link between this cat-associated parasite and brain cancer in people.

Toxoplasma gondii is a protozoal parasite. Cats are the natural host and can (but rarely do) pass the parasite oocysts (eggs) in their feces. People can be infected by ingestion of Toxoplasma oocysts that have been outside of the cat long enough (24 hours or more) to develop into an infectious form. Human Toxoplasma exposure is common, although this is typically not acquired directly from pet cats.  Adult cats rarely shed oocysts, whereas exposure from contaminated soil (e.g. from working in a garden and not washing ones hands afterward) or undercooked meat of various kinds are also important sources in different areas. Almost always, when a person gets infected, disease does not occur. Rather, the immune system contains the parasite, but is unable to kill it completely.  The parasite therefore often enters a dormant state forming small cysts in various body tissues, including in the brain.

Most concern regarding Toxoplasma involves pregnant women who have not been previously exposed to the parasite (and therefore have no antibodies to fight it off quickly). If they become infected during pregnancy, serious infection of the fetus can occur. Another problem in people is Toxoplasma encephalitis, a severe brain condition that occurs most commonly in people with compromised immune systems (e.g. HIV patients), typically from re-activation of dormant Toxoplasma. 

The recent paper by Thomas et al raises an additional concern: brain cancer. The basic premise of the paper is that some types of persistent infections might be able to induce mutations at the cellular level, resulting in cancer. Since Toxoplasma can cause longterm but dormant infection in the brain, they investigated a possible linkage.

The researchers took international statistics about malignant brain cancer from the International Agency for Research on Cancer database to determine brain cancer rates in different countries. They then compared these to Toxoplasma antibody rate data from 37 countries (from a 2006 paper that collected data from other papers). They found that the prevalence of antibodies against Toxoplasma in a country was related to the prevalence of brain cancer in the country (that's an oversimplification of what they did, since they did various kinds of statistical analyses, but that was their basic conclusion).

Some things to consider, though, before you ask for an MRI because you're a cat owner:

• This is a pretty superficial study. When I started reading it, I assumed they had done a case-control study, whereby they took a group of people with brain tumours and an equivalent group of people without brain tumours, and compared Toxoplasma antibody rates. That's not what was done. Rather, what they are essentially saying is that the incidence of brain tumours is higher in countries with a higher incidence of Toxoplasma antibodies in people. There are potentially a lot of other factors that might be involved. For example, they also showed that the incidence of brain cancer increased with increased gross domestic product (GDP) of the country, i.e. brain cancer rates are higher in wealthier countries. This could be because brain cancers are most often diagnosed as a result of more advanced medical care or that there are other lifestyle issues that might be risk factors for cancer. Toxoplasma antibody rates may be higher in high GDP countries (possibly because more people own cats, or for a number of other reasons) and thus the statistics shown an association between brain cancer and Toxoplasma antibodies.  It does NOT mean that Toxoplasma infection is necessarily causing brain cancer.  As the authors say, "This leaves open the possibility that brain cancers and T. gondii are both affected by a third correlated factor."
• This study included all brain tumours. It's hard to believe that Toxoplasma would be a risk factor for all of the various brain tumour types, if there is actually an association.
• The Toxoplasma prevalence data weren't obtained in a standard manner by the researchers. Rather, they took data from a paper written in 2006. That paper obtained the data from various other published papers, some decades old. It doesn't mean that the data are not valid, but using data from studies that collected the information in different ways and from vastly different time periods creates some weaknesses.
• Studies that are looking at a subject from a high level don't necessarily tell you what the risk is at the individual level. As the authors state "...analyses of data aggregated at the population level may not pertain to individual risk." (In epidemiology, this is called the ecological fallacy.)
• A large percentage of the human population (~1/3) has antibodies to Toxoplasma, indicating previous infection. That's a huge number, yet the incidence of brain cancer is very low overall. Certainly, even if there is a true association, the likelihood of an individual developing cancer from Toxoplasma is very low.
• Pet cats rarely shed Toxoplasma. They usually only shed for a couple of weeks of their life, typically when they're kittens. Also, the Toxoplama oocysts must live in the environment for 24 hours or longer to become infectious and a person has to ingest them to get infected. Therefore basic hygiene practices should reduce the chance of exposure even if a cat is shedding oocysts.

This is an example of a study that is great for generating questions that need to be answered, but not answering the questions. They've shown a crude association between toxoplasmosis and brain cancer. What that means is more detailed study is needed to see if the association is real (i.e. not the result of some other correlated factor) and furthermore to try to determine if the association is actually causative. Unfortunately, the press and internet don't understand that aspect and freak people out with statements such as "Cat parasite linked to brain cancer. A parasite spread by cats could almost double their owner's chance of developing brain cancer, research suggests."

One of the paper's concluding statements sums it up nicely: "Clearly, further research is necessary to determine the proximate links between T. gondii and different types of brain tumours and to investigate a mechanism of action." That means we need to work to determine what the true nature of the association is, and not panic at the possibilities.

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Dusty, the dog who tested positive for Hendra virus exposure on a Queensland farm, has been euthanized. The owners confirmed through their Member of Parliament that their pet had been euthanized voluntarily, rather than waiting for Biosecurity Queensland to compel them to do so.

Based on publicly available information, this seems like an illogical and unnecessary response, as well as an unethical approach by the government because it did not explain the implications of a positive result when they ask for voluntary testing of the dog.

The family said Dusty was euthanized because "most recent blood tests confirmed that he carried Hendra virus antibodies, which meant he was able to shed the virus to other animals." However, that's false. If government officials told them that, that's incredibly frustrating, disappointing and concerning. Antibodies have nothing to do with being infectious. I carry antibodies in my blood to a wide range of viral diseases that I've had over the course of my life. That doesn't mean that I still have the viruses in m. The presence of antibodies simply means the body has been exposed and mounted an immune response.

All information that I've seen so far indicates that there's no evidence that the dog was shedding virus and therefore no evidence that it posed a potential infectious risk. Furthermore, an experimental study from 1994 showed that infected dogs did not shed the virus. So, unless there are new data that aren't being released, euthanasia is a completely unnecessary and illogical response, probably based more on fear of liability than any evidence or reasonable assessment of risk. It would have been better to quarantine and monitor the dog, to prevent unnecessary euthanasia and to learn more about this virus in dogs.

If evidence indicating a true risk of transmission of Hendra virus from pets exists, this information needs to be released so that other pet owners in Queensland know what the situation is. If not, more common sense needs to be used when dealing with this disease in such animals.

(click image for source)

This Worms & Germs blog entry was originally posted on equIDblog on 01-Aug-11.

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Neil Fearon and his family have lost three horses to Hendra virus, and are concerned about one other. They are now dealing with the implications of their dog, a Kelpie named Dusty, having tested positive for Hendra virus antibodies in its blood. As I mentioned in yesterday's post, the presence of antibodies in the blood of this dog, detected during voluntary testing as part of the outbreak response, only indicates that the dog was exposed to the virus. Viral shedding was not identified, suggesting that the exposure was a prior event and that an active infection was not present. Despite this, government authorities are requiring that the Hendra antibody-positive dog be euthanized.

Poor communication and mixed messages are often the cause of problems during outbreak management, and this seems to be the case here. Based on the news reports, there are some pretty concerning issues.

Testing of the dog was voluntary and the owner was not notified that euthanasia would be required if the dog tested positive.

• This is rather unethical. People need to understand the implications of outbreak control measures. It's not fair to have such an aggressive response to a voluntary test without proper notification.

Mixed messages are being given about the risk the dog poses to the family.

• Authorities want to euthanize the dog, indicating they must believe there is some risk. However, the owner is very concerned about his 11-year-old son who has slept with the dog in his bed for the last few weeks. Yet, ABC news indicates authorities reassured Mr. Fearon that the risks are minimal. If the risks are minimal from that type of prolonged, close contact during the period when the dog may have been actively infected, it's hard to justify euthanasia after the fact on the basis of the dog posing a risk to people or animals (especially when the virus is endemic in the bat population in the area).
• Why euthanasia is being required seems to be unclear. While fear of Hendra virus shedding makes the most sense, Queensland's chief vet has stated that the dog will be euthanized as a precaution because "As a result of that infection, it may make it aggressive." It seems rather strange to euthanize a dog because of concern that an infection (which may not be active) might cause aggression, with no evidence that disease will occur or that it can cause aggression in dogs. Quarantine and observation would make more sense. There are a lot more dogs that are prone to aggression wandering around Australia.

This type of action drives things underground.

• When overly-aggressive actions are used, and people either don't agree with them or don't understand them, faith in the system decreases. What's the likelihood that people are going to allow their pets to be tested now? I assume it's a lot lower now that they've seen what will happen. So, the ability to determine exposure of other species and the potential risks from other species will be impacted.

Hendra virus is not something with which to play around. It's a very serious disease and one must err on the side of caution. How far you err on the side of caution is the question, and it's a hard thing to determine. It's easy to be very strict when setting rules, and fear of liability or fear of making a subjective decision often override logical thought and discussion.

As a somewhat informed outsider, I have a hard time supporting mandatory euthanasia for a dog that has evidence of previous infection but no evidence of active viral shedding. Yes, no test for virus shedding is 100%, but a pretty high level of assurance can be obtained and the dog can be quarantined for further testing. There's no indication from laboratory studies that I know of that dogs (or other non-bat species) can become longterm carriers of the virus. The owners should be involved in the decision making process and be given enough information to understand the implications of keeping the dog, the risks that might be present, and what they can do to reduce the risks. Government authorities need to clearly state their concerns and the evidence supporting them. With that, it's easier to make a logical plan that protects the public but is also appropriate for the animal and its owners. If the risk is deemed to be real and/or the owners are not willing to accept some degree of risk, then euthanasia is reasonable.

"Kill the dog" is an easy knee-jerk response. I simply don't see the evidence supporting it. Is it possible that authorities have a true reason to be concerned? Sure, but if so, that indicates another communication problem. If there is really evidence that this dog is a concern, this needs to be clearly communicated so people understand what's happening and why such drastic actions are being taken.

(click image for source)

This Worms & Germs blog entry was originally posted on equIDblog on 27-Jul-11.

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A 73-year-old New Jersey woman has died of rabies after being bitten by an infected dog. The woman was visiting Haiti in April when she was bitten, and she developed signs of neurological disease in late June. Family members and healthcare workers are being assessed to determine whether they may have been exposed to rabies during care of the woman. If so, post-exposure treatment would be started.

Rabies is a devastating but almost 100% preventable disease. While rare in most developed countries, canine rabies is a huge problem internationally and kills tens of thousands of people every year. The main reason it kills so many people is because of inadequate access to proper post-exposure treatment or failure to seek medical care. Timely access to post-exposure care can virtually guarantee that a person won't get rabies.

Why this woman didn't get post-exposure prophylaxis (I'm making the assumption that she didn't) isn't reported, and it could be because of patient or healthcare factors such as:

• Assuming a minor bite isn't a big deal.
• Not thinking about the potential for rabies.
• No access to adequate heatlhcare.
• The physician not thinking about rabies.
• Inadequate or no supply of rabies vaccine (for post-exposure treatment).

All of these problems can occur.  Education of the public and medical personnel, as well as ensuring adequate access to rabies vaccine, are critical to prevention.

More information about rabies can be found in the Worms & Germs Resources page.

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A Chapel Hill, North Carolina woman is suing Orange County in response to quarantine of her dog because of possible rabies exposure. This lawsuit highlights some of the inconsistencies in application of current rules, along with some misunderstandings.

In February, her dog Russell was barking at something under her deck, and that something ended up being a raccoon with rabies. There's no evidence of a fight or contact, but it can't be ruled out. Because of this, the dog was considered potentially exposed. Russell was overdue for his rabies booster, so a strict six-month quarantine was required, and the county required that this be done at an approved facility, not in the home. (The alternative option was euthanasia.)

• The lawsuit is based on the inconsistent application of the rules by various counties. The owner is seeking permission to quarantine the dog at home. This is allowed in many regions, provided there is confidence that the owner is responsible enough to properly quarantine the animal.
• It's a reasonable argument that's based on subjective and variable application of rabies guidelines. Certainly, formal quarantine in a facility offers more containment. The question is when household quarantine is appropriate, in terms of the animal's risk of exposure and the ability of the household to properly quarantine the animal.

Some other highlights:

Russell was overdue for his rabies vaccine by 46 days.

• Dogs don't immediately go from protected to unprotected. Certainly, we want animals to be up-to-date on their vaccines, but some thought needs to go into dealing with potentially exposed overdue animals. The NASPHV Rabies Compendium states "Animals overdue for a booster vaccination need to be evaluated on a case-by-case basis (e.g. severity of exposure, time elapsed since last vaccination, number of prior vaccinations, current health status, local rabies epidemiology)."
• Knowing the age of the dog and the number of previous vaccines would help, but the news article reports vaccinations (plural), suggesting that he's been vaccinated more than once in the past. In a dog with a relatively low index of exposure that was only overdue by 46 days, it would seem reasonable to consider it protected and treat it as vaccinated (although it's hard to say this definitively based on a news report that doesn't give the whole story). It's a critical point because considering the dog up-to-date would only result in a 45 day observation period as opposed to a strict six-month quarantine. 

The owner's veterinarian stated that research shows that an animal that is vaccinated regularly is protected for many years, if not a lifetime.

• Yes and no. Vaccination is quite effective and in most animals probably confers long-lasting protection. However, I'm not aware of research that really shows this. This isn't a disease where we have good research data about duration of effect of vaccination. I suspect that most dogs that have been regularly vaccinated are well protected. Most does not equal all, and with a disease like rabies, you have to be quite sure.

A rabies antibody titre was measured. This is a blood test indicating the level of anti-rabies antibodies. The veterinarian indicated that the titre showed Russell is currently protected from contracting rabies.

• Unfortunately, no. TItres tell you antibody levels, but we don't have good data about what is actually protective. Higher is better, but we can't say a certain number is absolutely protective. Back to the NASPHV guidelines: "Titers do not directly correlate with protection because other immunologic factors also play a role in preventing rabies, and our abilities to measure and interpret those other factors are not well developed. Therefore, evidence of circulating rabies virus antibodies should not be used as a substitute for current vaccination in managing rabies exposures or determining the need for booster vaccinations in animals". That statement was echoed by North Carolina's state public health veterinarian, Dr. Carl WIlliams.

This is a tough situation. In many circumstances, home quarantine is a reasonable option. It's easier on everyone involved, by not separating the dog from the household. It's also less expensive. However, it inherently comes with some degree of risk to the household and the community. It's only a reasonable option when it's certain that people will take "strict quarantine" seriously, and truly quarantine the animal. That's hard to assess, and regulatory bodies are presumably afraid of assuming liability should they allow someone to quarantine an animal at home and something bad happens (e.g. it develops rabies and exposes people in the household, the owners take it outside where it encounters other animals or people, it escapes...). Determining whether someone can and will properly quarantine an animal isn't easy, and those issues presumably lead some people to err on the side of caution, and require formal quarantine at an approved facility.

The easiest way to avoid all this: Ensure your pets are properly vaccinated.

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When it comes to public health concerns about staphylococcal bacteria from pets, most of the attention gets paid to methicillin-resistant strains like MRSA. That's not surprising considering how important MRSA is in human medicine. However, staph that aren't methicillin-resistant can also be a problem, since they can cause the same types of infections that resistant types can (they are just easier to treat). Another issue that often gets overlooked is staphylococcal food poisoning.

Staphylococcal food poisoning is one of the most common foodborne illnesses and results from growth of certain strains of staphylococci in poorly handled or stored foods. If staph get into food and the food is kept at improper temperatures, the bacteria can grow. If the strain of staph that's in the food is one that can produce enterotoxins, these toxins can accumulate in the food at high enough levels to cause food poisoning when eaten. In most cases, people are probably the origin of enterotoxin-producing staph that contaminate food, but pets are another possible source.

A recent study in Vector-borne and Zoonotic Diseases (Abdel-moein et al 2011) looked at enterotoxigenic staph in 70 dogs and 47 cats. Swabs were collected from the mouth, nose and wounds. Nasal swabs were also collected from 26 people. The researchers isolated enterotoxigenic Staphylococcus aureus (strains of S. aureus that possessed genes for enterotoxin production) from 10% of dogs and 2.1% of cats, as well as 7.7% of people. Most of the positive samples from pets were oral samples.

This study shows that dogs and cats can be potential sources of strains of S. aureus that cause food poisoning. Since the staph are often in the animals' mouths (and therefore presumably shed in saliva), animals can potentially contaminate food with these enterotoxigenic staph fairly easily, but it's unknown how often this occurs.

Prevention measures are pretty basic but should be considered, including:

• Keeping pets off kitchen counters.
• Discarding foods that pets have licked.
• Washing hands after pet contact, before handling food.
• Properly storing food, so that even if it gets contaminated with staph, the bacteria don't get the opportunity to grow and produce toxins.
• Photo from http://www.wagreflex.com/2009/06/taking-cat-ownership-to-the-next-level.html

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An Irish woman has won a record, multi-million Euro settlement after developing severe disease while working at a pet store. Patricia Ingle was a healthy 19-year-old when she was working in a Limerick, Ireland pet store. Then she developed psittacosis, an infection caused by the bacterium Chlamydophila psittaci, which she most likely contracted from a cockatiel at the store. It doesn't sound like the source of infection was confirmed, but the bird-associated nature of the bacterium (and presumably no other high-risk source of infection for the person) and the timing of disease with respect to contact with the cockatiel, are strongly suggestive. 

Exposure to C. psittaci is an ever-present risk when working with psittacines, especially when they come from various sources and are mixed and stressed, as often occurs in pet stores. Human infections are rare, and they are usually treatable if diagnosed and managed properly. Usually, flu-like disease develops in people, however Ms. Ingle developed severe and permanent neurological disease (malpractice in management of her infection was also alleged).

This is yet another example of the need for proper education and training. Not all infections are preventable, and not all infections indicate liability. If this store had a proper training program in place, adequately informed staff of potential risks and had sound protocols in place to reduce the risk of exposure, it would have been possible to argue that this was an unavoidable infection in someone that knew the risks. In the absence of proper training, education and protocols, however, there's no way to successfully argue that any infection was not preventable, and the liability should shift to the employer. Hopefully this is a wake-up call for pet stores (as well as other facilities like veterinary clinics) that while you can never eliminate infectious disease exposure, you have a moral and legal requirement to take practical measures to protect staff, visitors and other people.

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The Tennessee Aquarium in Chattanooga is being sued for $2.4 million by the parents of a child who allegedly acquired an infection after petting stingrays and sharks. The news report contains very little information, but the reference to "fish-handler's bacteria" means the infection was presumably caused by the bacterium Erysipelothrix rhusiopathiae. This bacterium can be found in various animal species, particularly pigs, and can be spread to people. The risk of infection is greatest in people with pre-existing skin lesions, since these allow the bacterium to bypass the normal skin barrier. It can also be found in/on fish, and infections in fish handlers tend to occur because they have close contact with fish and they often have skin lesions from fish, knives or other sharp objects, hence the name fish-handler's disease. When infection occurs, it is usually limited to a local skin infection, but more invasive infections involving deeper tissues or infections that spread to other parts of the body can rarely occur. In this case, the child must have had a deeper infection since according to the report he's had to undergo multiple surgeries.

Aquarium officials (unsurprisingly) refute the suggestion that the aquarium was the source, pointing to five negative water tests after the child's visit to the facility. Unfortunately, water tests taken after the suspected time of exposure don't really tell you much. It's going to be hard to prove anything, but it's reasonable to suspect that the aquarium was the source. This is a rare infection that can be associated with contact with fish and their environment, and the child had that kind of contact. Looking at other potential sources of exposure like pig contact is also necessary.

Even if no other potential sources of exposure are identified, it's still not definitive that the child acquired the infection at the aquarium, nor does it necessarily mean that the aquarium is at fault. Every contact with an animal or its environment (just like any contact with a person) carries some degree of infectious disease risk. The key issue is whether the facility took reasonable precautions to reduce that risk. In particular, this would include providing easy access to a handwashing or hand sanitizer station immediately after the contact occurred, and clear signs indicating the need for hand hygiene. Any animal contact event, be it a traditional petting zoo, pony rides or aquatic contact exhibits like this one, need to take those basic precautions. If proper measures are used, infections can still occur, but that's a fact of life. We cannot prevent 100% of infectious diseases. What we try to do is reduce the risk as much as possible, while maintaining the benefits of activities that involve animal contact. It's a balancing act and it's never perfect, but that's all we can do and what we need to expect from animal contact events.

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Using logic akin to "Chocolate cake? It has flour, eggs and milk. It's virtually health food. You should eat it every day.", AllPetNews.com has an article on its site entitled "Dog saliva has healing properties." The article focuses on potential beneficial compounds in saliva, with specific reference to a University of Florida (Gainesville) discovery of nerve growth factor (NGF) in saliva (although I can't find any reference to nerve growth factor in dog saliva on PubMed).

The article states "Wounds that were treated with NGF actually healed twice as fast as untreated wounds, indicating that if a dog does lick a humans wound, it could in fact lead to a faster recovery."

The problem here is taking some controlled research data and spinning it out of control. Putting synthesized or concentrated nerve growth factor on a wound in a controlled manner is different from putting saliva on a wound, which is also different from having a dog lick it. You have to consider the whole picture when evaluating potential treatments. For example, rubbing alcohol kills bacteria nicely but that doesn't mean it's a good idea to put it on a wound to prevent infection. It hurts and it damages tissue. While it may kill superficial bacteria, the tissue damage can ultimately increase the risk of infection.

While there are certainly some compounds in dog (and human) saliva that stimulate healing, those potential benefits need to be weighed against the potential adverse effects, particularly infection. The oral cavity of the dog contains billions of bacteria from hundreds of different bacterial species. Many of these are able to cause infection given the right circumstances. A wound helps create the right circumstance by breaking down the body's normal protective barriers.

The article does mention some dangers, although only with licking of deep wounds (a wound doesn't have to be deep to become infected), and concludes with:

"Although the healing properties outweigh the negative impacts there will always be a number of people that find it in their best interest to treat a wound by cleaning it with soap and water...."

• At this point, there's no evidence that the beneficial properties of dog saliva outweigh the negative impacts. In reality, people would be better off if they carefully cleaned wounds with soap and water. Licking may not cause a problem in many (or even most) situations, but it can lead to serious infection, and the lack of clear evidence of benefit alongside documented risks indicate that this is an inappropriate activity.

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An interesting study published recently in Veterinary Dermatology (Bartlett et al 2011) looked at bacterial contamination of ear cleaning solutions used on dogs at home. Ear cleaners are widely used by dog owners, but since the bottles the cleaners come in are used repeatedly and can have direct contact with the ear, there’s a chance for contamination of the bottle and/or its contents.

In this study, the researchers collected ear cleaner bottles from dog owners and cultured both the applicator tips and the contents. Bacterial contamination was detected on 10% of the bottle tips and in 2% of the solutions. The relative numbers make sense, since the tips are most likely to have contact with the ear. Regardless, this shows that a small but still reasonable percentage of bottles contain bacteria that could be inoculated into the ear.

Finding bugs is one thing, but determining if they are types that can cause disease is another. The researchers identified a few different bacteria, including Staphylococcus pseudintermedius, which is an important cause of ear infections. This isn't too surprising since the bugs that cause infection are typically those that are also normally found in (healthy) ears at low levels (and therefore the types of bugs with which cleaner bottles might have contact).

Expired ear cleaners were more often contaminated. This doesn’t necessarily mean that age leads to increased risk of contamination. It could just indicate that bottles that have been used more and over longer periods of time are more likely to become contaminated. Similarly, large bottles more often had contaminated tips, probably because of more overall use (and correspondingly more chance for contamination).

An interesting aspect was the finding that solutions containing Tris-EDTA had higher contamination rates. Tris-EDTA is a solution that is often included in ear cleaners as it has been shown to be useful for treatment of infections caused by Gram-negative bacteria.

What does this mean for people that clean their dogs’ ears? It’s hard to say. We don’t know whether a little bit of bacterial contamination poses a realistic risk. However, it’s reasonable to consider using smaller bottles and discarding them after they are used to treat a dog with an ear infection (as opposed to regular ear cleaning).

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An article in the May/June edition of Canadian Vet Newsmagazine (a magazine, not to be confused with Canadian Veterinary Journal, a scientific journal), described an interesting case of an indoor pet bird acquiring an infection from a wild raccoon, despite no direct contact.

The bird was an African Grey Parrot that was admitted to the Ontario Veterinary College because it had developed neurological abnormalities over the preceding few weeks: a head tilt, unsteadiness and problems climbing. Infection of the brain caused by the raccoon roundworm Baylisascaris procyonis was suspected and treatment was started, however unfortunately (but not surprisingly) the bird continued to deteriorate and was eventually euthanized. Baylisascaris infection was confirmed at necropsy.

Baylisascaris procyonis, the raccoon roundworm, is extremely common in raccoons, with the majority of raccoons in some areas shedding the eggs of this parasite in their feces. The eggs are extremely hardy and can survive for long periods of time in the environment. The tendency of raccoons to defecate in the same areas (raccoon latrines) means that very high concentrations of eggs can be found in some spots. While this is a raccoon-origin parasite, it can occasionally cause infection in other species (including people and dogs, albeit very rarely). After ingestion of the parasite eggs, the eggs hatch and parasite larvae migrate through the body, causing damage to various tissues as they go. If they migrate through the brain, severe neurological disease can occur.

An interesting aspect of this case is the fact that it was an indoor parrot. If this was a dog that had been exposed to a raccoon latrine, while it would have been a rare occurrence of disease, the origin of infection would have made sense. Here, the parasite eggs had to somehow make it into the house and then into the parrot. The suspected source was branches that were collected from the backyard and placed in the bird's cage. The branches were presumably contaminated with Baylisascaris eggs, and the bird ingested some while chewing on the branches.

This is a very rare situation, but the article includes some basic recommendations:

• Never adopt a raccoon (for many reasons beyond the Baylisascaris risk to pet birds).
• Don't keep parrots in outdoor enclosures where raccoons have access.
• Don't put parrots in outdoor enclosures that may have previously housed raccoons.
• Avoid putting objects from raccoon-inhabited areas into parrot cages or treat them to kill eggs. Heating objects to 62C for 1 minute should kill any eggs that are present.
• Ensure that cage bedding and bird feed are not potentially contaminated with raccoon feces.

(click image for source)

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Dr. Andrew Peregrine, a veterinary parasitologist at the Ontario Veterinary College, presented some data about the types of Giardia found in dogs and cats in Ontario at this week's University of Guelph Centre for Public Health and Zoonoses annual meeting.

A lot of attention has been paid to Giardia types in recent years. That's because, contrary to earlier thoughts, it's now known that certain types (also called assemblages) of Giardia can infect multiple species while others are host specific (i.e. they only infect one species). This is very important because if a dog or cat is shedding Giardia in their stool, the type determines whether there is any risk to people.

In the Ontario study, 75 canine and 13 feline Giardia-positive fecal samples were typed. In canine samples, assemblage D accounted for 68% of samples, while assemblage C accounted for 31%. These two are dog-specific, meaning 99% of typed canine samples contained only dog-specific types and were therefore no risk to human health. The other sample contained assemblage B, a zoonotic type that infects humans and animals. In contrast, 13/13 of the feline samples were assemblage A, a zoonotic type of Giardia.

These recent Ontario data indicate a low risk of transmission of Giardia from dogs to people, but some risk from cats - at least in Ontario. It's important to note that there appears to be geographic variation in this trend. Other recent studies have reported similar results, with the predominance of dog-specific types in dogs. However, a few studies have shown a predominance of the zoonotic assemblage A in dogs. These have mainly been in low socioeconomic status areas with infrastructure challenges that could increase the chance of dogs being exposed to human feces. Therefore, it may be that in areas where there is good sanitation, dogs are most likely to get Giardia from other dogs. When there are sanitation challenges, dogs may be more likely to be exposed to human types. So, it's important to know trends in different geographic regions to understand the risk of transmission from pets to humans.

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I have no problem with people considering "alternative" therapies for the treatment of infections. I perform research on non-antibiotic alternatives and hope that results pan out in the field. I have problems, however, with people that use unproven alternative therapies in lieu of proven conventional treatment or stray from the "do no harm" philosophy.

I read an article on aromatherapy in pets that highlighted my concern. Someone can make Fluffy or Fido smell whatever they want (although my dog Meg's concept of what smells nice certainly differs from mine - she'd rather roll around on a decomposing carcass than a lavender plant). I don't think it's going to help, but it shouldn't hurt. This article went beyond that, though, talking about application of substances to treat infections. Putting tea tree oil into a dog's ear isn't aromatherapy, it's topical therapy.

Is it an issue of semantics? No.

Essential oils like tea tree oil have some powerful properties. Just because it's "natural" doesn't mean it's safe. We know that tea tree oil has antibacterial properties. However, we also know it can be toxic. There are reports of serious adverse effects in people from tea tree oil ingestion and I know of severe reactions in dogs (including 1 death) thought to be due to excessive tea tree oil application. Adverse effects can result from the dog ingesting the oil by licking it off its coat or from direct effects on the skin.

A research study presented by Dr. Becky Valentine at the 2011 North American Veterinary Dermatology Forum highlighted this concern. Her research showed that while tea tree oil was able to kill methicillin-resistant Staphylococcus pseudintermedius (MRSP), a leading cause of canine ear and skin infections, it was also quite toxic to canine skin cells. So, the cost-benefit of tea tree oil is unclear since it certainly has some toxic properties, particularly when compared to other topical therapies such as chlorhexidine, that are essentially non-toxic.

Additionally, in a good demonstration of "all pain, no gain," Dr. Valentine's research showed that grapefruit seed extract, another compound available over the counter, had no effect on MRSP but had significant toxic effects on canine skin cells.

What does this mean? It means that essential oils and any other alternative therapies need to be studied, just like any other treatment. We need safety studies to know they won't cause problems, dosage studies to know how to use them and efficacy studies to know if they work. Natural products can be quite powerful and potentially useful, but they need proper testing.

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Although limited on information, there's a recent report of a person with rabies in California, with some hope for survival. Rabies was apparently diagnosed in the person on May 6. Incredibly, not only is the woman alive, but she is reported to be in "stable condition" and improving at UC Davis Medical Center. That's remarkable because rabies is almost always fatal, and death usually occurs fairly quickly by the time rabies is suspected and diagnosed. Rabies survival has been reported but is extremely rare.

While it's far too early to talk about survival and cure of the woman's illness, there are many different factors that could be involved in this potentially successful treatment.  These include very rapid administration of anti-rabies treatment, use of the "Milwaukee protocol" (which was the first successful treatment protocol for rabies in a person, which has also failed to be successful numerous times since), pre-existing partial immunity from previous vaccination, and/or the whims of biology and the immune system. Hopefully, this person will continue to improve and more information will be made available about why treatment has been successful so far.

The source of rabies is suspected to have been feral cats, although this is far from certain and it may be that this presumption is based on the lack of other more likely possibilities. While this is an encouraging report, it doesn't change the fact that rabies almost always kills, and it's almost 100% preventable with proper post-exposure treatment. People need to be aware of how to avoid rabies and that prompt treatment is needed anytime rabies might have been encountered.

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Today (like most days) I answered questions about the potential for transmission of methicillin-resistant Staphylococcus pseudintermedius (MRSP) between people and pets. We have a long way to go before we fully understand the issues, but research continues to progress and we're learning more and more. A recent study by Dr. Engeline van Duijkeren and colleagues from Utrecht University published in Veterinary Microbiology (van Duijkeren et al. 2011) steps up our knowledge another notch.

In their study, the authors enrolled 20 households that owned pets with MRSP infections. They went into the households and collected samples from the index pet (the one with the MRSP infection), other pets, people and the household environment.  At the time of sampling, 10 of the infected pets had gotten over their illness while the other 10 still had active infections.

Some highlights of the study:

• 4/14 (36%) of other dogs and 4/13 (31%) other cats in the households were MRSP carriers. In households where the pet still had an active infection, an astounding 86% of the other animals were carriers. All these numbers are much higher than the expected baseline rate of MRSP carriage by healthy pets in households, giving strong support to the notion that MRSP is being passed between pets in households with an infected pet.  From an infection control standpoint, it's probably reasonable to assume that a pet living with an infected animal is a carrier.
• MRSP was isolated from 2/45 (4%) of nasal swabs from people. This is not too surprising, since we know that MRSP (and its susceptible counterpart, methicillin-susceptible S. pseudintermedius (MSSP)) can be transmitted between people and pets. This study shows us, however, that even when there is apparent MRSP transmission going on between pets in the household, it doesn't seem to commonly involve people.
• MRSP was found in the environment in 70% of houses (and 90% of household where the pet was still infected). These are pretty big numbers but are not really unexpected, since if MRSP is in and/or on animals, it's bound to be found in the environment. Whether the environment is a potential source of human or animal infection isn't known, but it's something to consider.

This research gives more evidence that MRSP can be spread readily between animals but less so between animals and people. It could be because animals have closer contact with each other in a household than with people, but a bigger factor is probably that S. pseudintermedius is more adapted to living on animals than on people.

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Rabbit hemorrhagic disease (RHD), a rare and reportable disease, has been identified in a pet rabbit from Winnipeg, Manitoba. The affected adult male rabbit was taken to a veterinary clinic in March after being lethargic for a short period of time. It was diagnosed with liver failure and subsequently died. The rabbit's body was forwarded to the Manitoba Ministry of Agriculture, Food and Rural Initiatives animal health laboratory. Various tests were performed and rabbit hemorrhagic disease was identified.

Rabbit hemorrhagic disease is a viral disease caused by a calicivirus. It is a serious infection that has high death rates and spreads very rapidly between rabbits through direct contact and through contaminated items such as cages and bedding.  It does not affect people. Caliciviruses are non-enveloped viruses - viruses of this kind are very hardy, and can survive in the environment for long periods of time. RHD is reportable in Canada, and has not, to my knowledge, been identified in the country before. It's endemic in wild rabbits in many countries, and is thought to have made its way to North America in 1988 in a shipment of frozen rabbits from China to a supermarket in Mexico City. It's been found in the US in sporadic outbreaks since 2000.

Finding RHD in a Canadian rabbit perhaps isn't too surprising, since it's been identified in the US periodically over the past decade. However, this is a strange situation. The affected Manitoba rabbit lived in an apartment with two other pet rabbits, and did not have any outdoor access or contact with any other rabbits (or any other wildlife). These other two rabbits were fine. They were quarantined initially but have since been released from quarantine since they stayed healthy and tests for the virus were negative.

So, where did the virus come from? That's a baffling question, because this virus is a rare and exotic disease that is not known to be elsewhere in Canada. It would have been a lot less surprising if this was in a rabbit with outdoor access or that had had contact with other rabbits (outside of a confined household group). No source has been reported, but I assume authorities have looked at aspects like the owner's contact with rabbits or wildlife, the owner's contact with areas where wild rabbits might live, when the other rabbits were obtained and from where, and whether the owner has brought rabbit meat into the house. Although mice and similar rodents aren't known to be susceptible to the virus, checking for a rodent infestation in the house would be another consideration at in a strange situation like this.

Why were the other rabbits unaffected? That's surprising as well, considering how easily the virus is normally transmitted.

Another thing this story highlights is the usefulness of diagnostic testing. I'm impressed that the owners and veterinarian submitted the rabbit's body for testing. Too often, an animal that dies of a strange disease is just buried or cremated. That's understandable from an emotional aspect, but often it occurs because testing is not even discussed after an animal has died, or because people don't think about why it might be useful. Cost is an issue, as testing is not typically subsidized for non-food-animals (in this case, even though it was a pet, I presume the rabbit was treated as a food animal, with a lot of testing done for free). While testing won't help the dead animal, it can provide useful information at times, beyond finding a rare foreign disease. It's not uncommon for me to get a call from someone saying "my dog recently died of some strange disease, is it safe for me to get a new puppy or do I have to do something first?" or less commonly "I'm sick and the doctors haven't figured it out. My dog died last month of something strange, do you think they could be linked?' With only a vague clinical description, there's often not much I can say.

Rare diseases are just that - rare. The odds of encountering one are quite low, but they do happen. Arriving at a diagnosis can help identify risks to other pets and people, and it is often money and time well spent.

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I guess I'm lucky I'm married since I'm obviously out of touch with the best ways to attract women. Unlike Dewayne Yarborough of Ford Heights, Illinois, I didn't know that a 4-foot-long alligator is a "chick magnet."

His reason for keeping the reptile was that he claimed it attracted women (I kid you not).  While it may have attracted a few dates, it ended up costing Mr. Yarborough, as he was charged with possession of an illegal animal. Investigators found the alligator in a fish tank in the man's kitchen. Apparently, he was keeping it in a small tank and feeding it minimally (aka starving it) to keep it from growing too big. (Apparently, the degree of attraction of women is not directly proportional to the size of the alligator.)

Besides being illegal in many jurisdictions, keeping alligators is rarely a good idea. They can grow very large and can be very aggressive. They need lots of space, a proper environment and a proper diet. Like all other reptiles, they are a potential source of Salmonella (and some other microorganisms), so keeping them in the kitchen is an even worse idea.

I wonder what other animal-associated dating trends I've missed over the past few years...

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As petting zoo season approaches (along with petting zoo-associated disease outbreak season, unfortunately), it's important for people who run petting zoos and other animal contact events to think about what they do to reduce the risk of infecting visitors. No petting zoo will ever be 100% safe, because any person-animal contact (just like any person-person contact) carries some degree of risk. However, the risks can be greatly minimized by some basic measures, such that the benefits of animal contact can greatly outweigh the risks for most people.

One of the standard guideline documents for managing public person-animal contact is the National Association of State Public Health Veterinarians (NASPHV) Compendium of Measures to Prevent Disease Associated With Animals in Public Settings, which has just be updated again for 2011. Anyone planning a petting zoo or similar event should know this document well and ensure that their event fulfills all the recommendations within it.

Hopefully, petting zoo operators will pay attention to these guidelines out of a desire to safeguard the health of their visitors. If that's not enough motivation, the liability aspect should be considered. Since there are well established and readily available guidelines, failing to use them could certainly increase the legal liability risk.

(click image for source)

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Another recent incident highlights yet again problems with untrained or inadequately trained service dogs.

The incident in question occurred in March, when Ava, a 14-month-old German Shepherd "service animal," lunged at a six-year-old child who lived next door. It sounds like the dog was roaming free and attacked the girl on her property. There's some debate about whether or not the girl was playing with the dog (which doesn't really matter because a service dog shouldn't attack under circumstances like that, nor should it be roaming at large). Anyway, the girl suffered a serious bite to her face that required more than 100 stitches to close.

Ava was owned by a family whose nine-year-old daughter has cancer. The dog was "trained" to steady the girl when she's dizzy. That may certainly be a good role for a service dog, as there is a wide range of beneficial activities that proper service dogs can perform. However, real service dogs are highly trained and closely evaluated, with a significant effort dedicated to making sure the dog is properly behaved and does not pose a risk to others. That's the problem here. While Ava might have been good for this one particular child, it doesn't sound like there was any training to protect the public (and if there was, it was woefully inadequate).

Ava apparently also bit another child in the fall, compounding the concerns. A settlement between the neighbours has resulted in the dog being removed from the township, with no declaration that she's dangerous, but also nothing preventing the likely lawsuit to recover medical costs, if not more.

There's nothing good that comes from a situation like this. A young girl has lost her dog, another young girl has suffered a serious bite, and true service dogs - that play a critical role in the lives of many people - get lumped in with these untrained animals.

If someone wants and needs a service dog, it's important to facilitate that. At the same time, if someone is going to take advantage of the benefits of having a service dog (e.g. broader access) they need to have an adequately trained, true service animal. Too many "service animals" are just pets with basically no additional training, but serious training is required for the animal to both do a real job as well as to ensure that there is minimal risk to the public.

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A bird specialty store owner wrote me recently, concerned about potential tuberculosis (TB) exposure. A client's bird had been diagnosed with "human TB" and that person had spent a lot of time with the bird. The source of the TB hadn't been identified, and the store owner was worried about the risk that he/she had been exposed as well.

Is it really TB?

The first thing to consider in a case like this is whether TB was really present. "Human TB" is caused by Mycobacterium tuberculosis. Birds can be infected by M. tuberculosis, but are more often infected by Mycobacterium avium complex (MAC), a related group of bacteria. Based on what the store owner wrote here, it seems that M. tuberculosis was the cause of disease.

Can TB be spread from birds to people?

Probably, but the evidence is sparse. Tuberculosis can be spread from people to birds, and it's likely it can go the opposite direction. However, close and prolonged contact is typically required for TB transmission. Human-to-bird cases tend to be birds owned by people with active TB who have close mouth-to-mouth contact with their birds (e.g. mouth-beak feeding).

What is the likelihood of transmission?

Being in the same room as a bird with TB is probably pretty low risk (just like casual contact with a person carrying TB is low risk). The risk also depends to a degree on the type of disease the bird has. If it has respiratory tract disease it is probably more likely to be shedding the bacterium in its respiratory secretions, which poses a greater risk of transmission than other forms of the disease.

Is there cause for concern?

I guess there's always some degree of concern when it comes to TB, but I assume the likelihood of transmission of TB from the bird to the store owner is quite low. The source of TB wasn't known, but most likely the bird was infected by its owner, and if so, being around the bird's owner is probably as (or more) risky.

(click image for source)

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Easter is one of those holidays when there are concerns about dumb pet purchases. Spur-of-the-moment purchases of inappropriate pets can lead to animal suffering and death, and risk of human infection. Easter's problems: baby chicks and rabbits.

Rabbits can make great pets. They're a long-term commitment, but they’re relatively low maintenance, a lot is known about how to raise them and they are generally low risk for transmission of infections to people. Chicks are a different story. Chicks are notorious Salmonella vectors and have been linked to numerous outbreaks. They are easily injured and often improperly raised. They also grow up (well, some of them do, at least) to be full sized poultry, something that most people don't really want.

A story from Vidalia, Georgia highlights some of the issues with Easter pets. In it, Tracy Gunn describes his need to buy a chick for his daughter - and not just any old chick, but a dyed chick, something that’s illegal in 36 US states, but not Georgia.  Gunn states "I don't know what she's going to do with it." Sounds like a recipe for a few minutes of novelty, followed by a relatively short life for the chick. At least his daughter’s 17, and not in the high risk group for salmonellosis.

Alongside the cage full of multicoloured chicks was a collection of rabbits.

“The bunnies sell real good for Easter.  We've been selling a lot of them about the last month. Can't keep enough of them.” said a store employee.

He followed that up with “They buy (rabbits) for their kids for Easter, then they take Easter pictures and stuff like that with them, I'm not sure about what happens to them afterward.”

That’s the problem. Kids get a few minutes of novelty enjoyment, but then a lot of those animals end up dead, released into the wild (not a good thing) or dropped off at an animal shelter, because people don't think about the "afterward" part before they buy.

Pet purchases need to be made with thought and foresight:

• Do I really want this pet?
• Am I committed to taking care of it for its entire life?
• Can I take care of it properly with my current living situation?
• Can I afford to take care of it properly?
• How do I take care of it?
• Are there any disease risks that I need to be concerned about?
• Are there any people in the household who are at high risk for disease caused by this type of animal?

If you can't answer these questions, don't buy or adopt an animal - of any kind.

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A Montreal pediatrics resident has expressed concern about rat bite fever in kids. Dr. Karine Khatchadourian described three cases of this bacterial infection in a paper called "The rise of the rats: a growing paediatric issue," published last year in the journal Paediatrics and Child Health. The article didn't really present any evidence that this is a "growing" issue, but it is a disease of concern.

Rat bite fever is a bacterial infection most commonly (but not exclusively) associated with bites from rats. Healthy rats often carry the bacterium that causes the disease (Streptobacillis moniliformis in North America), and infection can occur when the bacterium is inoculated into the body by a bite, or when it's spread to mucous membranes like the mouth through direct mouth-mouth contact with pet rats (yes, some people kiss their rats).

The disease can be serious, and even fatal, if not properly diagnosed and treated. It's also a classic example of why physicians need to ask their patients about pet contact and why people need to take bites from pets seriously. Knowing that a rat is in the house, and particularly if a bite has occurred, is a key factor in helping make the diagnosis. If the physician doesn't ask the question, this critical piece of information may be missed, along with the diagnosis.

Being concerned about rat bite fever (and other zoonoses) is good, and ways to educate pet owners and physicians about such diseases are needed. However, extrapolating "rat bite fever is bad" to "rats are bad" is a stretch. The statement in the paper "Should we, as health care professionals, advocate to have rats banned from being sold in pets stores?" is over the top.

Every animal carries many microorganisms that can cause disease in people, given the right circumstances. Similarly, every person you meet is carrying something infectious. The key things to consider are:

• What is the likelihood of infection?
• How severe is the disease that may occur?
• What can be done to reduce the risk of infection?
• What is the cost-benefit, i.e. how do the potential risks compare to the potential benefits?

How can the risks be reduced?

• Rat owners need to be aware of the disease.
• Good handling practices are needed to reduce the risk of bites.
• Any bites that occur should be promptly cleaned and a physician contacted if there are concerns.
• Contact of rat saliva with broken skin or mucous membranes (e.g. kissing the rat) should be avoided.
• Physicians need to know whether their patients own pets, including rats, and know what diseases may be associated with those types of animals.

With this type of approach, the risk of infection can be reduced and the ability to properly and promptly diagnose the disease, in the odd case that it occurs, can be maximized.

I don't want to downplay rat bite fever. It certainly can cause illness, particularly in children under the age of 12.  A recent paper reported a fatal case in a 14-month-old boy, however in that case the infection was associated with ferrets, not a rat.

Parents of small children need to think about the risks of zoonotic diseases, as well as injuries (e.g. bites) when deciding whether to get a pet, and what type of pet to get. If people like rats, take care of them properly and communicate well with their physician (and if their physician is aware of the issues), then the risks of serious disease are quite low.

Dr. Khatchadourian suggests that parents "should stick to cats and dogs, and steer clear of rats." However, that's no assurance that a zoonotic infection will not occur. There's no evidence indicating the risk of disease is less with those species. It doesn't even eliminate the risk of rat bite fever, since Streptobacillus moniliformis can be found in the mouths of dogs too.

Rather than banning rats from pet stores, we should focus on educating pet owners, veterinarians and physicians about zoonotic diseases.

(click image for source)

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People for the Ethical Treatment of Animals (PETA) is battling Ringling Brothers and Barnum and Bailey Circus because of Karen, an elephant with tuberculosis (TB). The animal rights group is claiming that the elephant poses a public health risk because she has TB, and it appears that their appeal had initially convinced Baltimore city council to bar the animal from performing.

However, while Karen does have TB (along with about 12% of all Asian elephants in captivity in North America) she does not have active disease. This means she is not known to be shedding Mycobacterium tuberculosis, the cause of TB. Standard protocols are for captive elephants to be tested each year for TB shedding through culture of trunk washes, whereby the elephant essentially sucks some fluid into its trunk and blows it back into a collection bag. If TB is grown from that sample, the elephant has active disease and needs to be quarantined. Since Karen does not have active disease (and because close and prolonged contact are needed for transmission of TB), she is not believed to pose any public health risk. 

Recently, I wrote about an outbreak of TB in people that worked with infected elephants at a sanctuary. That was a totally different situation from this one. The major differences, particularly with regard to the risk of transmission, are perhaps best explained by one of the authors of that report, Dr. William Schaffner, who said "If you're at a circus, you're at a great distance from the elephants. You do not have genuinely prolonged contact with them. You're there for 2 hours of the show. That sort of exposure should not put people at risk. I would let my grandchildren attend."

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The US CDC is investigating a large, long-lasting and widely dispersed outbreak of salmonellosis that has been linked to contact with pet frogs, such as African dwarf frogs (see image). Between April 1, 2009 and April 5, 2011, 217 infections were identified in people in 41 states. A strain of Salmonella Typhimurium has been implicated.

Of the 217 infected people, 34% were hospitalized, which is quite a large proportion, but is probably due (at least in part) to the fact that stool samples aren't often cultured from people with milder disease (who don't go to the hospital). If you have severe diarrhea and are in hospital, you're more likely to be tested. As with most outbreaks, the 217 diagnosed cases presumably represent only the tip of the iceberg.

Of the people who got sick, 64% reported contact with frogs in the week before their illness began. Of these, 84% had contact with African dwarf frogs. This type of widespread outbreak with a single strain and a fairly clear link to a specific type of animal raises questions about whether there's a major breeder or supplier that is the source of the problem. Not surprisingly, the investigation identified a single water frog breeder in California as the source of frogs associated with this outbreak. Salmonella was identified from environmental samples at the breeder's facility. Testing is still apparently underway to confirm whether it's the outbreak strain, but it's pretty likely.

As with any other reptiles or amphibians, there are standard recommendations to avoid infections from aquatic (water) frogs:

• They should not be in households with high-risk people: children less than five years of age, the elderly, pregnant women and immunocompromised individuals.
• Care should be taken to prevent contamination of the house from aquarium/terrarium water.
• To avoid contamination, aquarium water should not be dumped down kitchen or bathroom sinks.
• Hands should be washed thoroughly after contact with aquarium water or the frogs themselves.

Photo: An African dwarf frog (Hymenochirus boettgeri) (photo credit: James Gathany).

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When I give presentations to veterinarians about infection control, I often talk about legal liability as one reason they need a good infection control program. I talk about the potential bad scenarios, such as someone getting an MRSA infection from an animal and then turning around and suing the vet. I usually say something like "I don't think it's happened yet, but you never want to be an index case". I may need to change that line now that a Texas veterinary clinic is being sued over a person's MRSA infection.

However, the lawsuit, filed April 4, isn't from an owner. Rather, it's from a veterinary assistant. The woman is suing the clinic, claiming they were negligent because they didn't warn her that she would be caring for an MRSA-infected animal. She claims that she contracted the infection on the job and that it "has physically impaired her for the rest of her life."

I know nothing about this case beyond what's in the link above, however it raises a few important issues and questions.

What does this mean for the veterinary clinic?

• I've been saying for years that the bar is being raised and clinics need a good infection control program, including training and education, to reduce infections of both pets and people.
• As awareness of zoonotic diseases and veterinary infection control increases, the potential for lawsuits may similarly increase.

What level of warning is required for veterinary employees?

• This varies with the type of person.
• A veterinarian shouldn't need to be informed that they will work with animals carrying zoonotic pathogens. If they didn't pick that up in vet school, they've got some other major issues.
• A veterinary technician should have a similar understanding of the risks and measures that should be undertaken to reduce those risks.
• Lay personnel are a different story. You can't assume a lay employee has any knowledge whatsoever about infectious diseases, zoonotic diseases or infection control.
• If there are minors in the clinic (e.g. co-op students, volunteers), you need to go even farther, and there should be written notification of parents of the risks, and measures that are taken to reduce the risks.
• In general, the less the veterinary education, the greater the need for clear and documented education about disease avoidance.
  

How do you prove this person acquired MRSA on the job?

• That's tough. Perhaps there was a clear link with a case. Even stronger would be showing that the human and animal MRSA strains were the same, but that's unlikely to have been done. Just because MRSA can be found in animals doesn't mean that MRSA infections all come from animals. Humans are thought to be the source of the vast majority of MRSA infections and pets, and while pets can potentially spread it back to people, this is ultimately a human disease. People pick up MRSA all the time in the general population, although the percentage  of people who carry it at any given time is still low.
• MRSA carriage rates have been shown to be higher in veterinarians than in the general public in a few different studies. I think it's clear that MRSA exposure is a risk of veterinary practice. However, proving that an individual infection came from a pet in a clinic is still difficult.

How can vet clinics reduce the risk of MRSA (and other) infections, as well as lawsuits?

• Have an infection control program in place.
• Make sure infection control practices and policies are written down.
• Make sure all employees are appropriately trained and document the training.
• Make sure people follow all of the required protocols.

Infection control isn't rocket science. At its heart, it's the application of some very basic practices. Infection control hasn't had a high profile in companion animal veterinary medicine in the past, but things are changing (albeit slowly). Available resources can help veterinary clinics implement a decent infection control program with minimal effort. A good resource is the document Infection Prevention and Control Best Practices for Small Animal Veterinary Clinics, which is available (free) for download on the Worms & Germs Resources page.

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Leptospirosis is disease caused by several types of Leptospira bacteria. It's often called a re-emerging disease in dogs, because the incidence has been increasing over the past couple of decades in many areas. While the overall number of infections is limited, when it does occur lepto can cause serious disease, including kidney failure. It's also a zoonotic disease: lepto can be transmitted from sick dogs to the people who handle them. Infected animals shed the bacteria in their urine, and when the urine comes in contact with broken skin or mucous membranes (mouth, eyes, nose), transmission of infection can result.

Canine vaccines against lepto are available. In the past, lepto vaccination hasn't been all that popular because the vaccines tended to have a higher rate of side effects compared to most vaccines, and the types of lepto that the vaccines targeted were often not the most important types causing disease. This has changed more recently as newer vaccines have become available. These vaccines seem to have low rates of adverse effects and provide protection against the four types of lepto that tend to be the most important. These vaccines have also been shown in research studies to protect against disease and to reduce shedding of the lepto bacterium in urine (thereby decreasing the risk of transmission to other animals or people).

Lepto is not among the "core" vaccines that groups say all dogs should have. That's because the risk of lepto exposure varies greatly between regions and dogs. The key thing to consider when deciding whether or not to vaccinate is what each individual dog's risk of exposure is. The main reservoir of lepto is wildlife such as rats and raccoons. If infected wildlife are in the area, they may be peeing out lepto and contaminating the environment, particularly any type of standing water (lepto loves to live in warm, wet environments).

In the past, much of the concern has been focused on dogs that go out and swim in streams or ponds.  The "poster child" for lepto has typically been the Labrador Retriever that goes out gallivanting in the bush, but that may be changing too.  When you consider where wildlife such as rats and raccoons live and how high the wildlife infection rates can be, remember that these pests can be present in urban areas in incredibly large numbers.  Living in a city does not make a dog safe from exposure to lepto. In fact some urban areas, with large numbers of wildlife crowded into high-traffic areas like parks, are probably higher risk than rural areas.

Deciding on vaccinating requires an understanding of how common lepto is in the area and whether there is a risk of exposure for the individual animal. This is a disease for which a veterinarian's understanding of disease patterns in an area (including any specific areas that be particularly high risk) and the types of possible exposure of the dog play a big role. There's no "one size fits all" recommendation for lepto vaccination.

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A sure sign of spring is the proliferation of classrooms hatching out chicken or duck eggs. While chicks may be cute and entertaining, they are also high-risk sources of Salmonella and some other infectious microorganisms. Numerous Salmonella outbreaks have been linked to contact with hatchling chicks, and care must be taken if teachers are considering having chicks in classrooms.

Things to consider:

• Who will be in contact with the chicks? Children under 5 years of age, pregnant women and people with compromised immune systems should not have contact with young chicks. This rules out having chicks in preschool and some kindergarten classes, however not everyone follows those standard recommendations. It's also very hard to know whether there may be immunocompromised kids in the classroom. Unless a teacher/school is sure that there are no high-risk children present, they shouldn't have high risk animals.
• Where will the chicks be hatched and raised? Is it in a contained area?
• Is the chick area easily and always supervised to ensure that rules are followed? This is important for both children and chicks, since chicks can easily be injured or killed through improper handling.
• Are protocols in place regarding safe handling and hygiene?
• Are the chicks going to be in an area where students eat?
• Are parents going to be notified in advance?
• Are there plans for sending the birds to an appropriate home when they're done in the classroom?
• Are the chicks there for a true educational purpose, or just as a novelty?

Hatching chicks can be done relatively safely in appropriate classrooms, with older children, no high-risk individuals, easy access to hand hygiene stations, appropriate protocols and proper supervision. The problem is, these aren't always (or even often) present, and inadequate thought often goes into bringing chicks into classrooms.

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The pandemic H1N1 influenza virus continues to circulate, although the hype has certainly died down. During the original 2009 pandemic, there were a few reports of infection of domestic animals, particularly ferrets and cats. This wasn't particularly surprising since we know these species are susceptible to human influenza viruses, and with so many people infected and so many people owning pets, a large number of pets were presumably exposed, and a few got sick.

Three animals from the San Diego Zoo also developed H1N1 influenza in the fall of 2009: a badger, a Bornean binturong (also known as a bearcat, see photo) and a ferret. The badger and binturong had severe pneumonia and had to be euthanized, but the ferret survived. Presumably, these animals were infected by an infected person, probably a caretaker. This report just provides more evidence of the ability of this virus to infect a diverse range of species, and the need to consider both the potential role of various animal species in human influenza transmission and the potential for animal disease from contact with infected people.

Photo: A binturong (Arctictis binturong) at Overloon, NL (photo credit: Tassilo Rau, source: http://en.wikipedia.org)

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In some situations, bringing a pet to work might be acceptable. In other situations, it's totally inappropriate. A UK dentist learned that the hard way.

Ian Hulme-Ribsy, a dentist, was found guilty of unprofessional and inappropriate conduct for several bad behaviours. One was that he brought his dog to his dental clinic and failed to clean his hands after handling it. That's a pretty blatant breach of basic infection control practices, in the sense of both having an animal in a patient care area (outside of a structured visitation program) and failure to use basic standards of hygiene to reduce the risk of disease transmission. (It's particularly troubling when you consider that as a dentist the man would be putting his unwashed fingers directly in patients' mouths.)  It's pretty remarkable considering how much attention is generally paid to infection control in the dental world.

Also included in his list of bad behaviours was giving patients sedatives in liquid form without measuring. He'd just pour some into a plastic cup. Reckless disregard for dosing of sedatives is probably a bigger concern than the dog issue, but both show poor judgment.

Mr. Hulme-Ribsy didn't lose his license, but must practice with restrictions. "... Hulme-Rigby must work under supervision and take courses in record keeping, infection control and dental practice ethics. He must undergo annual infection control and record keeping audits, and is banned from administering benzodiazepine drugs, or any other sedatives. Hulme-Rigby’s case will then be reviewed to decide if he is fit to practise without restrictions."

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Kinkajous are strange little mammals from the Procyonidae family - the same family to which raccoons belong. Kinkajous are native to Central and South America and are occasionally kept as pets, but they don't make great pets because they are strictly nocturnal, can be cranky when woken during the day, and can sometimes be aggressive. Regardless, there is a niche pet trade, particularly in the US.

A recent report in Morbidity and Mortality Weekly Report describes detection of Baylisascaris procyonis (the raccoon roundworm) in pet kinkajous in the US, including:

• A 10-week-old kinkajou in Tennessee in which Baylisascaris procyonis was found during a routine fecal examination.
• Detection of Baylisascaris eggs from soil samples under the cages of a kinkajou breeder in Florida (the breeder from which the Tennessee animal was obtained).
• An unrelated case (11 years earlier) in which adult Baylisascaris worms were found in the intestinal tract of two adult kinkajous that died of other causes.

No human infections (i.e. cases of larval migrans) were linked to infected kinkiajous.

Baylisascaris is a parasite that's extremely common in raccoons, rare (but concerning and sometimes over-hyped) in dogs, and an extremely rare cause of disease in people. While rare in humans, it still gets a lot of attention because when disease does occur, it can cause serious neurological damage, typically in children. The damage is caused by migration of parasite larvae through the body, and through the brain. This can occur after someone swallows infective parasite eggs, which then hatch in the intestinal tract and then embark on their journey through the body.

It's unclear whether Baylisascaris is a common problem in kinkajous (like it is in raccoons) or a rare finding (like it is in dogs), since this report only describes the parasite in a small number of animals, and no larger studies of intestinal parasites in kinkajous have been reported. It would be useful to know whether kinkajous are true reservoirs of this parasite (and therefore whether we should consider all kinkajous to be carriers) or whether infection is just an unusual finding.

Overall, the public health risk is likely limited.

• There aren't that many pet kinkajous around, as far as I know.
• While Baylisascaris is nothing to dismiss, to get infected, a person still has to eat infective eggs from feces. The likelihood of transmission from a pet to a person is therefore low if good basic hygiene measures are used.
• The parasite eggs are not immediately infectious. They have to sit around in the environment before they are infectious, usually for 2-4 weeks. Therefore, prompt removal of feces and careful attention to basic practices like hand hygiene should greatly reduce the risk of transmission.
• Routine testing and deworming of pet kinkajous should reduce the risk even further.

What does this mean for pet kinkajou owners? Not a lot beyond what would normally be recommended. Pet kinkajous should have good veterinary care and regular fecal examinations. Regular deworming should be discussed with the attending veterinarian, and good hygiene practices should be used to avoid contact with feces, especially old feces.

Photo credit: Robrrb at en.wikipedia

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ProMedMail tends to publish a monthly rabies report. While a lot of it involves the same basic issues, there are sometimes a few more interesting stories:

Rabies in a donkey in Georgia

• Like all mammals, donkeys are susceptible to rabies virus but infections are not particularly common. Raccoon rabies has also be identified in the area, and a bite from a raccoon may have been the source.

Bite from a rabid kitten in Pennsylvania

• A York County woman was bitten by a kitten that ran into her house when the door was opened for someone else. The kitten bit her when she grabbed it to throw it (hopefully not violently) back outside... an understandable reaction but not what you want to do in a case like this. You need to know whether a wild animal that bites is rabid, and if it gets away, you can't test it. You need to get away from it but keep it contained until someone can come get it. The other problem with people getting rid of the animal is that they might not recognize the risk of rabies. In this case, the kitten was hit by a car after being removed from the house, which allowed for it to be tested.

Yet another report of a dog being exposed to rabies through contact with wildlife, then being euthanized because it was not properly vaccinated.

• An unvaccinated animal that has been exposed to a rabid animal has to be euthanized or undergo a strict six-month quarantine. A vaccinated animal only needs a 45-day observation at home.

Rabid bobcat attack in Florida

• Encountering a manic bobcat isn't something I'd like to do, and a LaCrosse, Florida woman spent nine days in hospital after being attacked by one. The 25-pound cat was trying to get the family's cat, then lunged at the woman when she came outside the house, aiming for her neck. Her husband then shot it. They knew that the bobcat needed to be examined, and took the rather unusual approach of bringing it to the hospital emergency room with them (I'd love to have seen that). I don't imagine hospital personnel did anything, but Florida Fish and Wildlife Conservation Commission personnel came and got it, and later confirmed that it was rabid. (Image: Lynx rufus, US Fish & Wildlife Service)

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When a particular animal species or breed gets a lot of attention, such as through a popular movie or TV show, there's sometimes a major increase in people wanting one as a pet. The proliferation of Dalmatians after 101 Dalmatians, and people buying Jack Russell terriers in response to Eddie from Frasier are only two examples. Sometimes the trend is fine, but it can result in problems when people get breeds or species that really aren't right for them (this was a big problem with the Dalmatians), and with puppy mills pumping out large numbers of poor quality animals to meet the demand. The problems can be even worse when an exotic species is involved.

Concern has been expressed about the potential for this to occur following the success of the animated movie Rango. The movie features a chameleon, a fascinating reptile but also one that is not that easy to properly maintain in captivity and, like all reptiles, carries a risk of Salmonella transmission to household members. 

PETA and some other groups have expressed concern about a PetSmart promotion whereby people can get a $10 discount on reptiles if they bring in a Rango movie ticket stubs. 

Any increase in demand for chameleons resulting from this promotion will be trouble, because:

• Odds are most of the animals will not do well if purchased on a whim by someone who isn't adequately prepared to take care of them.
• Smuggling or legal importation of wild-caught chameleons will probably increase, with the associated very high death rates during the collection and shipping process.
• Chameleons may end up in households where reptiles are not appropriate, such as those with kids under five years of age, elderly individuals, pregnant women or people with compromised immune systems.

Hopefully the concerns are unfounded, but anyone considering purchasing a chameleon needs to carefully research the care requirements, be aware of the risk of disease transmission in the household, and should look for ethically sourced (i.e. captive bred and properly raised) animals.

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A letter in Emerging Infectious Diseases (Ludwig et al 2011) describes an uncommon Mycobacterium infection in a pet ferret, with potential human health concerns.

The three-year-old ferret from Germany was taken to a veterinarian with a five-month history of coughing, recent weight loss, vomiting and mild diarrhea. A chest radiograph was taken and "nodular densities" were found in the lungs (these would show up as white spots on the radiograph). This type of finding is usually an indication of something bad going on in the lungs, such as tumours or granulomas. Because of the poor prognosis, the ferret was euthanized. At necropsy, the lung nodules were confirmed, and there were some other abnormalities such as and enlarged spleen and a lot of enlarged lymph nodes. Using a combination of culture and molecular tests, Mycobacterium celatum infection was identified as the cause.

Mycobacteria are a diverse group of microorganisms, whose most notable member is M. tuberculosis, the cause of (not surprisingly) tuberculosis (TB) in humans. Mycobacterium celatum belongs a large group classified as 'non-tubercular' Mycobacterium species.

Mycobacterium celatum is rather uncommon, being first diagnosed in a person with AIDS in 1993, and only being reported sporadically in people since then. Most human infections have occurred in people with compromised immune systems, but there are some reports of people with apparently normal immune systems becoming infected. There is also one previous report of an infection in a ferret. There is no evidence that the ferret reported here had a compromised immune system, so the reason for the infection is not apparent. The source of infection is also unknown. Since there were granulomas throughout the lungs, it suggests that the ferret inhaled the organism, but that can't be proven and there are no clues even suggesting a possible source.

An interesting aspect of this report is the question about whether the ferret's owner may also have been infected. It's perhaps a bit of a stretch, but there was a suggestion that the owner may have been infected as well because he/she reported a chronic cough. Testing was performed and no Mycobacterium (of any species) was detected, but the person was treated with antibiotics prior to being tested so a false-negative culture is possible. The likelihood that the person was truly infected is probably quite low, but it can't be dismissed.

Ferret owners shouldn't be too worried about M. celatum. This is an example of one of many possible rare infections that can be encountered. Similarly, this report doesn't mean that ferrets should be considered at higher risk for causing human infections. Every animal poses some degree of risk to people, and ferrets are actually pretty low-risk overall. Mycobacterial infections aren't something to be too concerned about, but, as suggested in this report, the general concept of considering human disease when something is diagnosed in a pet is excellent and too often overlooked.

(Photo credit: Luke Rutherford)

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Petting zoos can be great events (I've said it before and I'll say it again!). I end up visiting many with my kids every year.  Despite the fact that a few petting-zoo-associated disease outbreaks also occur every year, and despite the fact that I deal with infectious diseases every day, I still don't get too concerned about the risk to my family.

Why not?

The main reason is that I can control one of the most important disease prevention measures: making sure my family washes their hands after being in the petting zoo (along with some other common sense measures).

Hand hygiene is a critical infection control tool, and poor hand hygiene practices are often part of the problem in outbreaks. Figuring out how to improve hand hygiene is an important research area, albeit one in which few people are working.

A paper by Maureen and I, published recently in Epidemiology and Infection, looked at hand hygiene compliance in a petting zoo and how to improve it. The study involved using webcams to remotely and discretely observe hand hygiene practices in people attending a petting zoo. We've previously done observer-based studies, where you have someone standing there watching, but it's possible that this method falsely elevates results because some people might notice they're being watched and be more likely to wash their hands. It's also easier to record a lot of data and evaluate it over time (i.e. by watching it on video), than try to collect everything accurately in real time.

The published study involved a large petting zoo at the University of Guelph's annual open house. It's a well designed and operated event, which needs to be considered when evaluating the results, since petting zoos vary greatly in quality.

Overall hand hygiene compliance at this particular event was 58%. That means 58% of people that came into the petting zoo washed their hands or used a hand sanitizer on the way out. (It doesn't mean they all did it well, but they at least they did something). In some ways, that number's good, when you compare to our earlier petting zoo observation study, (or even to results of hand hygiene rates of physicians in some hospitals). However, for such a short-term activity where there is easy access to facilities to wash hands or use a hand sanitizer, there's much room for improvement.

During the petting zoo, a few thing were changed at defined times to see if they would improve hand hygiene rates. Two things resulted in increased hand hygiene compliance; a combination of petting zoo personnel actively offering visitors hand sanitizer near the exit and improving hand hygiene signs, and having personnel walking through the zoo reminding people to wash their hands. This suggests that people need an active reminder to clean or sanitize their hands. Whether they don't think about it, or can't be bothered unless someone points it out, is unclear, but having personnel encouraging hand hygiene is something to consider to help improve infection control. It's practical for short-term events like petting zoos at fairs and similar exhibits, although perhaps not as practical for permanent exhibits.

People who entered pens or touched animals were more likely to wash their hands than people who didn't. This is presumably because people who had contact with animals were more likely to recognize a risk. However, while people who touch animals are presumably at higher risk, simply being in the area is enough to pick up an infection. In some outbreaks, people who went into the petting zoo but never touched an animal got sick. That's why there is a need to remind people that everyone must wash their hands after leaving a petting zoo, not just those who actually petted the animals.

A few other concerns were noted. Despite warnings on prominent signs, 10% of people carried food or drink into the petting zoo area. This probably increases disease transmission risks since people may eat or drink before they wash their hands, or directly contaminate their food or drink while in the petting zoo area.

Overall, hand hygiene rates weren't bad (and were better than I was expecting), but there is still room for improvement. Considering how quick, easy and cheap it is, there's no reason not to strive for 100% compliance. 

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I've been slow getting around to this topic, which has been covered elsewhere (on Barfblog), but it's an interesting report and one that's still worth discussing. The report from Ireland involves diagnosis of botulism in a baby that was associated with a pet turtle and/or the turtle's feed.

Botulism is a very serious disease caused by a toxin produced by the bacterium Clostridium botulinum. Typically, botulism occurs when a person (or animal) eats food that was contaminated with the bacterium and then was stored improperly, allowing the bacterium to grow and produce its potent neurotoxins. The other form of botulism, one that is largely restricted to infants, occurs when the botulism bacterium itself is swallowed and starts to produce its toxins while it's in the intestinal tract. It rarely occurs in older individuals because their natural intestinal bacterial population helps suppress overgrowth of the C. botulinum.

Not much information is available about the case in Ireland. It involved quite a rare strain of C. botulinum, Type E, and there's no information provided about how the link to the turtle was made. I assume it was toxicoinfectious botulism, whereby the infant ingested the bacterium (as opposed to eating something already containing the toxin) but the reports aren't clear. Fortunately, the child is recovering, since botulism can be fatal.

Botulism isn't high on my list of potential infectious diseases you can get from reptiles, but it can happen - and it has the potential to be very, very bad. Salmonella is the main focus of reptile-associated diseases, but this report should be taken as a reminder that there are other diseases of concern as well, and that reptiles are inappropriate pets for households with children under five years of age.

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A 44-year-old Taipei man is recovering from psittacosis, a potentially severe infection caused by the bacterium Chlamydophila psittaci, which he may have contracted from his pet bird. This bacterium is commonly found in certain bird species, particularly psittacines (parrot family), and human infections are typically associated with bird contact. Healthy birds can shed the bacterium in their respiratory secretions or feces, and shedding rates can be particularly high in some groups of birds, particularly large breeding colonies.

The affected man had typically vague initial signs of disease... fever, chills, aches and cough. It appears that he was tested for psittacosis about 10 days later, but the diagnosis was only recently made (It's not necessarily an easy diagnosis in some cases). There's no information about the severity of disease or whether it progressed past those initial relatively mild signs, or when treatment was started, but he's apparently responding well to treatment and is recovering at home. His pet bird is the probable source of infection, but it's unclear whether it's being tested.

Psittacosis is an example of a disease for which an understanding of pet contact by the attending physician is critical. Typically, psittacosis starts off with flu-like signs. Most otherwise healthy people with fever, chills and aches that go to their doctor would probably be told to "go home, rest and take an anti-inflammatory" or, less diplomatically "get your infectious body out of my office, stay at home, and get over it." That would be reasonable advice for most people, because most people with these symptoms have a common viral infection, and a disease like psittacosis is rare. However, if the person had contact with psittacines and the physician knew it, psittacosis would hopefully come to mind and testing might be performed. Psittacosis is usually easily treated, but you have to know to test for it to diagnose it, so that proper treatment can be started. Untreated, psittacosis can cause severe, even fatal, disease.

Physicians' knowledge about their patients' animal contacts and zoonotic disease exposure is often very poor, which compromises their ability to promptly diagnose and manage zoonotic diseases. Better understanding of pet-associated zoonoses and communication between both people and their physicians, and between physicians and veterinarians, is needed to help reduce the risks.

A great psittacosis resource is the National Association of State Public Health Veterinarians' Psittacosis Compendium.

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A recent press release from The Pet Care Trust reported on the status of its Pets in the Classroom program, which provides support to teachers to have pets in school classrooms. On the surface, it seems like a fine concept, helping to enrich school activities. However, it's one of those ideas that can do a lot of good, or it can also be very bad, depending on how the program is run.The Pet Care Trust has some useful information about pets in classrooms, and anyone considering having a pet in a classroom needs to be aware of a variety of concerns, including:

• Welfare of the pets (e.g. minimizing stress, preventing abuse)
• Adequacy of pet care, particularly during weekends and holidays
• Access to and cost of veterinary care
• Distraction of students
• Allergies
• Fear
• Infectious disease transmission

Given the topic of this blog, I'll focus on the last one.

Infectious disease transmission from pets in classrooms is a real problem. Zoonotic infections can and do occur in these situations. The risks are quite variable, and depending on the animal, children, classroom and pet care, can range from inconsequential to quite serious.

The type of animal is very important. Certain species are very high risk for carrying particular infectious diseases and for transmitting them to people. Reptiles are notorious for Salmonella, so it is recommended that children under five years of age and immunocompromised individuals (among others) not have contact with reptiles. Even with older kids there's a risk, and older kids have picked up Salmonella in classrooms from reptiles or a reptile's food (e.g. frozen rodents).

So, it's concerning that 435 of the 2066 grants handed out by this program were for reptiles, and included kindergarten to Grade 6 classrooms. A lot of reptiles went into classrooms with a lot of young kids. Typically, elementary school children (at least around here) eat in their classrooms, which raises even more concern. While the majority of students would be five years of age or older, immunocompromised kids are not exactly uncommon, and it's unclear whether teachers have adequate knowledge of whether kids in their classes are immunocompromised, nor whether they understand that such children are at increased risk of disease from classroom pets.

I'm not saying pets in classrooms are a bad idea. However, it's often done poorly and with little forethought. To be effective and safe, you need to consider many things, such as:

• What species should it be? From my standpoint, no reptiles or other high-risk species (e.g. baby chicks) should be in any classroom, because you can't guarantee a high-risk person won't be around. The animal needs to be small enough to be properly housed in a classroom. Its care requirements need to be basic and readily met. It shouldn't be a species that gets stressed easily, and it needs to be an animal that can tolerate all the activities that go on around it (e.g. a nocturnal species is probably not a good idea).
• What types of hygiene/infection control practices need to be used around the animal and how will they be enforced?
• What disease or injury (e.g. bite) risks are present and how will they be managed?
• Who will take care of it? This means who will take care of it for its lifespan, not just the upcoming school year.
• Who will arrange and pay for any medical expenses that arise, either for preventive medicine or treatment of disease?
• Will parents be notified?
• What happens if a child in the class is allergic to or afraid of the animal?
• Will proper supervision be available at all times?
• Who from the school or school board must give permission, and is there a standard approval process? (There should be, but there rarely is.)
• Why is the animal going to be there? Will there be any educational use or it is just there for fun/decoration?

If you can answer all these questions adequately, then a pet might be a good fit in the classroom in question. If you can't answer them, or can't be bothered to try to answer them, then there should be no pets in the classroom until you can.

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A recent article in Emerging Infectious Diseases discussed infectious disease risks associated with having pets in the bedroom. It raised awareness about pets and zoonotic diseases, although some of the coverage was a bit over the top. There are risks, but for most people and most pets, the risks are quite low. Some things do increase the risk quite substantially. One is sleeping with a large predatory carnivore.

Large exotic animals such as lions and tigers are surprisingly common in small zoos, animal parks, exhibitions and even private homes. Many people get away it, but all too often it's an accident waiting to happen, as for a 17-year-old Florida girl who sleeps with a tiger in her bed.

Felicia Frisco is part of a family of animal handlers. Her father runs an "institute" that provides animals for movies, TV shows, presentations and for the public to "cuddle." Felicia has been raising Will, a now six-month-old Bengal tiger. Part of Will's training involves sleeping in Felicia's bed every night.

Felicia said her friends "think it's really cool that I have a pet tiger because most of them only have a cat or dog." Other people (the one's with common sense) think it's an appalling example of poor animal handling and weak regulations (along with poor parenting).

Will may be very friendly now, but that doesn't mean he's safe. Many people have been killed by pet lions and tigers. Sometimes it's from attacks, but sometimes it's just the result of normal playful behaviour. A playful swat to the head or neck from a large cat can be fatal. Think how aggressively some cats play. Scale that up a few hundred pounds and you can see the potential for injury or death. As Will gets older, the risks will increase based on his increasing size and natural instincts. Also, there may be behavioural changes associated with sexual maturity that could increase the risks.

Felicia's father, the ringleader of the venture, seems to be in complete denial: "She may have that young cub in her room and be taking care of him and raising him, but her mother and father who are full time professional animal trainers also live there with her and have many other tigers right outside the door that are part of their living."

• Having someone in the next room doesn't prevent an attack. They just get to see the damage first.
• Having other tigers doesn't reduce the risk. It means there are more animals to cause problems and the potential for people to be injured getting into the middle of a cat-cat quarrel.
• Being a trainer doesn't make you invulnerable to teeth and claws (remember Siegfried and Roy?)

He further distances himself from parent-of-the-year honours by saying "That Felicia is risk-free is by no means true but neither are most 17-year-olds behind the wheel of a car... they die like flies across the country. It's like having an extreme sport in your life. The potential for accident and injury is certainly there."

Jack Hanna, a famous animal trainer, summed it up nicely: "Every cat has a different killing ability, the tiger it makes no difference, it's like they can go and it's a bomb going off wherever it hits."

(click image for source)

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An Irish study has reported a high rate of Salmonella contamination in pig ear treats. Various earlier studies have identified Salmonella in pig ear treats, and human infections have been associated with contact with such treats. Recommendations for processing and handling of pig ear treats have been made and have hopefully reduced the likelihood of contamination, but there's no information about adherence to these recommendations.

In the most recent study, published in Food Research International (Adley et al. 2011), researchers purchased 102 pig ears from 4 pet shops in Limerick City, Ireland. Salmonella was detected in 28% of samples. A variety of different Salmonella types were found, including antibiotic resistant strains and types that are common causes of disease in people.

Interestingly, all of the contaminated treats were from 2 of the 4 stores. The two negative stores only sold treats sourced from within the European Union, and one of them only sold pre-packaged treats. The other two stores sold treats sourced from the EU and Brazil, and sold some in bulk bins. All positive treats were from the same distributor, and all were from bulk bins.

The high prevalence of Salmonella in these treats is concerning, particularly in light of standard guidelines for processing such treats and and EU regulation that if treats are not Salmonella-free, they must have less than 1 Salmonella bacterium per 25 g of product.

Contamination of bulk bin treats isn't surprising, as I mentioned in a post just the other day. Bulk bins allow for cross contamination, and a single positive treat (or a single contaminated hand going into the bin) can result in contamination of many other treats. Also, picking treats out of a bulk bin can potentially contaminate consumers' hands, and there's an additional concern that bulk bins are often kept at a level where young children (a high risk group) can access them.

Contact with Salmonella in pig ear treats is a risk, and people should wash their hands after any contact with a pet treat. Avoiding bulk bin treats is a good idea. Purchasing irradiated and individually packaged treats should also help reduce the risk. Unfortunately, stores do a lousy job of notifying people about the risk. As the paper states "We recommend public awareness advertising in pet shops to alert pet owners of the risks associated with pig ear pet treats and hygiene practices that should be followed."

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Merrick Pet Care has recalled Junior Texas Taffy pet treats because of the potential for contamination with Salmonella. No illnesses have been reported but contamination of treats could pose a risk to both pets and owners.

Contamination of pet treats is not uncommonly reported, but the overall scope of the problem isn't well understood. Outbreaks of salmonellosis in people have been reported in association with handling contaminated treats. The impact on animal health is unclear. Most recalls are not associated with reports of animal illness, however it's possible that small numbers of sporadic cases of disease would not be identified or reported.

Recalls like this highlight the potential risk from any pet treat or pet food. You can never absolutely eliminate risk but you can do things that will probably reduce the risk and identify situations where there are greater concerns.

• Packaged treats may be lower risk than treats from bulk-bins, because a single contaminated item can lead to cross contamination of many others in these large bins.
• Individually packaged irradiated treats are presumably of little to no risk.
• "Human-grade," "premium" or other catchy descriptions have absolutely no meaning with regard to food safety.
• People should wash their hands or use a hand sanitizer after handling treats.
• Care should be taken when handling any animal-based pet treats, particularly in households that include people with compromised immune systems, infants, elderly individuals or pregnant women. In these households, particular attention needs to be paid to handwashing after contact with treats, or - better yet - avoiding treats (or at least non-irradiated treats) altogether.

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Glanders, a very serious disease of horses, donkeys and mules caused by infection with the bacterium Burkholderia mallei, has made the news again in a rather unusual manner – it has been reported as the cause of an outbreak in lions and a tiger at an Iranian zoo in Tehran.

The story goes that two Amur tigers arrived at the Tehran zoo from Eastern Russia in April 2010 as part of an exchange program between the two countries. The tigers were supposed to be used to help restore the tiger population in northern Iran on the Miankaleh nature reserve, but their living quarters there were apparently still not ready, and thus they were being kept at the zoo. One of the tigers died in December 2010.

And that’s were the story starts to get a little dicey. The Iranians claim the tigers were imported already carrying the disease, and that the last case of glanders at the zoo was 50 years ago. The tigers had already been at the zoo for eight months - although the incubation period for glanders can be months in some cases, it is normally only weeks. The Russians of course insist that the tigers were completely healthy when they were transferred – they’d been thoroughly examined and quarantined prior to being moved. (This makes the most sense to me, since transporting an animal such a long distance is a major stress and increases the risk of illness, and transporting an animal that is already sick would be even more risky. Not a chance I would take with two members of a species of which there are fewer than 900 individuals left in the world.) They also pointed out that a sick tiger from the cold regions of Russia would be much more likely to succumb to illness during the very hot Iranian summer, not during the winter.

Another report said that three lions at the zoo also died from glanders in the last two months, and subsequently another 14 lions were diagnosed with the disease, all of which were put down by the authorities. The main concern seemed to be the spread of the disease from the big cats to the feral cat population, and then to the human population. This second report states that “the tiger died after being fed contaminated meat, though it is possible it could also be related to the glanders.”  Yet another report said that the tiger was infected with feline immunodeficiency virus (FIV - the feline equivalent of HIV).

Facts to keep in mind:

• Glanders is an highly contagious disease, and highly fatal (B. mallei is even classified as a Class B bioterrorism agent).
• Animals that do recover from the disease can become long-term carriers of B. mallei, and are a risk to other animals (and people). Prompt euthanasia of affected animals is therefore often the primary means of controlling outbreaks (but the bacterium is susceptible to antibiotics).
• The infection can be transmitted to other animals (and people), usually through close direct contact or contact with oral and nasal secretions and discharge from skin ulcers. It can also be transmitted by eating tissues from infected animals.
• The bacterium is killed by most disinfectants, and UV radiation (sunlight).

Glanders can affect species other than equids, including people and cats, however there is very little information available about glanders in any felids, let alone lions and tigers. Theoretically it might be possible for the disease to spread from the zoo animals to feral cats and then to people, but I don’t know how many feral cats are brave (or stupid) enough to wander into a lion enclosure. There’s also a possibility that a glanders-positive feral cat may have infected the zoo cats (but again, it would have to be very brave, or very stupid). It is also unclear what tests were used to confirm that the big cats were infected with glanders, and it is unknown if other animals at the zoo have been tested. Since this is typically a disease of equids (and has also been found in goats and camels), I would certainly be checking these animals first.

The big question is, where did the glanders come from in the first place? It seems unlikely that the tigers brought it from Russia, when the disease is actually endemic in Iran (even though they’d had no diagnosed cases at the zoo for many years). Is there a carrier animal in the zoo? Were the animals infected by eating contaminated meat? Was it brought in by feral cats?  The source needs to be identified and addressed or animals will continue to be infected, which is particularly bad news for the kinds of rare species that may be found in a zoological collection. Some more details about the testing would also be appreciated – given the severity of this disease, and the severity of the consequences for positive animals (euthanasia), one needs to be as sure as possible that these animals are infected with B. mallei and not something else.

Photo: Amur Tiger (Panthera tigris ssp. altaica) (click image for source)

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An upcoming article in the journal Emerging Infectious Diseases entitled "Zoonoses in the bedroom" has attracted some attention in the press. I haven't been able to access a copy yet, but will probably write about it soon. However, one article that was written about the paper had a pretty weak lead-in piece:

"Nikki Moustaki knew something was wrong when she got strep throat for the sixth time in a year. Her doctor wanted to take out her tonsils. But Moustaki, an otherwise healthy 30-something, was determined to uncover the source of the infection. "I saw a bunch of specialists, and one suggested my dog might be a carrier," said Moustaki, a New York City-based dog expert and trainer. "I had never thought of that. When you think of contagious diseases in dogs you think of rabies and ringworm, you don't think of strep." After four walks a day on the streets of Hell's Kitchen, Moustaki's dogs -- a schnauzer called Pepper and Ozzie, a schnoodle -- would curl up beside her in bed. Following her doctor's surprising suggestion, Moustaki started cleaning Pepper and Ozzie's paws with baby wipes after each walk. And she's been strep-free ever since."

While it's good to see the potential role of pets in human disease considered (since it's often overlooked), this is a example of the opposite end of the spectrum: implicating pets with absolutely no evidence, and actually, contrary to all available evidence. Saying that cleaning her dogs' feet prevented her from getting strep throat makes little sense on many levels. Firstly, if it actually made the difference, then she wasn't really getting strep from the dogs, it was coming into the house on the dogs' feet from the ground outside. There's no evidence the outdoor environment is a relevant source of strep. If strep was present on the dogs' feet, it would have to make it to her nose and mouth, and that degree of contact is hopefully unlikely (and if present, it would be associated with a lot bigger concerns that strep). Further, despite various studies, there is no evidence that dogs are even rare reservoirs of Group A Streptococcus, the cause of strep throat. Recurrent strep throat in people is caused by repeated exposure to infected people.

Like I said, it's good to see recognition of the potential role of pets. The next step, however, has to be looking for the evidence. It's not hard to find a few good references that talk about the role (or lack thereof in this case) of pets in human strep infections. Implicating the pet and recommending a rather bizarre foot hygiene regimen isn't really helping anyone.

Is it just coincidence that the infections have stopped in this woman? Probably. Recurrent infections don't tend to go on forever. However, maybe her increased attention to cleaning her dogs' paws also led to her paying more attention (consciously or otherwise) to her own hygiene practices, which would have probably played a greater role in disease prevention.

(click image for source)

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An interesting paper in the journal Emerging Infectious Diseases (Page et al. 2011) describes an impressively large effort to study the effect of anthelmintic (dewormer) baiting on parasite contamination at raccoon latrines sites in Indiana.

Raccoon latrines can be highly contaminated with various parasites, because raccoons congregate at these sites and use them as "communal toilets." Of all these parasites, the raccoon roundworm, Baylisascaris procyonis, gets the most attention.  It is very common in raccoons, but it is also a very rare cause of disease in people who swallow the infective parasite eggs from the environment.  In some of these people the parasite larvae can cause very serious neurological disease which can be very difficult to treat.

In this study, the research team identified 559 raccoon latrines in north-central Indiana. They removed debris from the areas and used a torch to help kill the parasite eggs that were there (this is one of the very few effective ways to kill the very hardy eggs of Baylisascaris). At a selection of latrine sites, they also collected baseline fecal samples. After this was all done, they distributed dewormer (pyrantel pamoate) baits in half the areas once a month (leaving the other half of the areas as controls). They then collected fecal samples at all the latrine sites approximately 6, 12 and 18 months later.

Fecal samples were tested for B. procyonis eggs. Also, they captured mice from some of the study patches. Like people, mice are intermediate hosts for B. procyonis, and they can be infected in the same manner, so researchers looked for B. procyonis larvae in the brains of the mice.

Overall, they tested 1797 fecal samples. In the first round of sampling, 33% of samples contained B. procyonis eggs. The prevalence of eggs decreases significantly (3-fold) after baiting by the first recheck, and stayed at that level throughout the study. By the one-year sample time, there was also a significant decline in B. procyonis larvae in the brains of mice (27% vs 38%).

This impressive study shows the potential impact of controlled and somewhat practical interventions on the presence of some concerning microorganisms. Certainly, no one is going to be able to treat all raccoon latrines with a torch. However, dewormer baiting might be a consideration in areas that are close to human populations, along with other control measures. Dewormer baiting could be relatively cost-effective in this case. It won't eliminate the problem, but it might help reduce environmental contamination and the associated potential for human and domestic animal exposure.

More information about Baylisascaris and raccoon latrines is available in our archives.

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Miami Beach officials, disturbed by reports of a hookworm outbreak, have taken a rather unique approach to the problem: they've created a cat and cat poop map.

This fall, several cases of cutaneous larval migrans were reported - and highly publicized - in the Miami Beach area, something that is of particular concern for a tourist city that doesn't want people thinking the city's beaches are biohazardous.

Cutaneous larval migrans is a skin condition caused by migration of hookworm larvae through the skin. Dogs and cats can be carries of hookworms and pass eggs in their feces. Larvae then hatch from these eggs and can penetrate the skin (of people and animals alike) after being in the environment for a few (usually 2-9) days. If someone has contact with infectious larvae, such as by stepping on them while bare foot on a beach, the larvae get into their skin and start migrating, causing this very itchy skin condition.

Feral (stray) cats are the main problem in Miami Beach. Stray cats and beaches are a bad combination, since stray cats tend to have high rates of hookworm carriage, they often defecate in sand on the beach, and of course people often have direct contact between bare skin and beach sand. Identifying where stray cats live (and poop) is important for disease control and public education. "We needed to identify where the cats are eating — and where they're pooping — to address this problem" stated a program organizer. To do this, city sanitation workers were given GPS devices and instructions to go find cats. Data were uploaded into a mapping system, and areas where cats tend to congregate were identified. Not surprisingly, certain areas of sane dunes are being used as industrial-sized litterboxes by the cats.

This type of information can be used in several ways. It can be useful for evaluating cat populations: where they are, where they go, and what happens to them over time. It can help identify areas where the cat population needs to be addressed through measures such as trap, neuter and release programs (as are being used in Miami Beach). It can also help with development of targeted education programs, by putting up warnings in heavily cat- and cat poop-infested areas. City health officials think that the combination of tracking, the increased spay/neuter program and targeted warnings to sunbathers have helped staunch the outbreak.

Image source: http://blogs.miaminewtimes.com

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Pseudorabies is one of those diseases with a really bad name (although it's a pretty bad disease too). It has nothing to do with rabies. Rather, it's caused by a herpesvirus; porcine herpesvirus 1. The name "pseudorabies" presumably came into existence because it causes neurological disease that, in some cases, can look like rabies.

Pigs are the reservoir of this virus, and it's a very important cause of pig disease in some regions. Spillover infections can occur in many different mammals, including dogs, cattle and sheep, and infections in these species are typically fatal.

Pseudorabies is not as widely distributed internationally as rabies, but it is present in wild boars in many regions, including many European countries. Infections in dogs are sporadically reported, typically in hunting dogs infected by contact with wild boars.

Recently, a case of pseudorabies (also known as Aujeszky's disease) was diagnosed in a dog in Luxembourg, the first diagnosis of the disease in the country since it was identified in domestic pigs in 1999. (Infections in wild boars were suspected in late 2009 but not confirmed.) Few clinical details are provided in the report to the OIE, beyond the fact that the dog died. Contact with "wild species" was listed as the source of the infection, which presumably was contact with wild boars.  

Unlike rabies, pseudorabies is not a significant concern in people.

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A Royal Oak, Michigan resident is undergoing rabies post-exposure prophylaxis after being bitten by a rabid cat. The person found a sick cat by the side of the road and took it to a vet clinic... a good deed in theory, but problematic in many ways. One obvious risk is the potential for rabies exposure, as occurred here. The cat was subsequently diagnosed as rabid, and having been bitten the good samaritan was clearly exposed. Fortunately, the veterinarian kept the contact information for the person who dropped off the cat, who can therefore now receive the necessary treatment.

Associated with this event, the Royal Oak Animal Shelter has issued the following reminder:

1. Do not approach any animal if it appears sick. Call the Police to get animal control involved.
   
2. Tell your children to stay away from any stray animals, whether they are skunks, dogs, or cats. Any of these could be infected.
   
3. Vaccinate your dogs for rabies. It is the law.
   
4. If you let your cats outside, STOP doing so. If you can't stop, please make sure your cats are vaccinated for rabies.
   
5. If they already have been vaccinated, talk to your veterinary professional about having a booster administered to protect your animal. There is no cure for this deadly disease.

(click image for source)

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A few days ago, I wrote about tuberculosis (TB) exposure in several people who performed a necropsy on an infected dog. As part of that investigation, a cat in the household was tested and was also positive for TB. It was euthanized because of the public health concerns. A logical question from a reader was "Is there no treatment for animals, as there is with humans?"

Diagnosis of tuberculosis in an animal often results in prompt euthanasia, and some individuals and groups have euthanasia as a standard recommendation.

Why?

• We have no data about how to properly treat an infected animal.
• We have no data about how effective (or ineffective) treatment may be.
• It's not easy to test animals before or during treatment to see if they are shedding the TB bacterium (Mycobacterium tuberculosis).
• It's such a concerning disease in people that the inclination is to err on the side of caution when it comes to public health.

Is it an appropriate response?

In some circumstances, it probably is. In other circumstances, treatment shouldn't necessarily be dismissed. A major problem is the knowledge gap.

• We don't know whether infected animals pose any risk to people. Human-animal transmission can occur, but it's unclear whether animals can transmit the infection back to people.
• If transmission between pets and people occurs, we don't know what circumstances are involved. TB is not readily transmitted even between people. Short term exposure is not a major concern. It's likely that close and prolonged contact is required for transmission from pets, but we don't know for sure.
• We don't know if certain infected animals are higher risk than others, although there probably are differences. A dog with respiratory TB and active disease is probably a much higher risk than a dog with a localized TB abscess.
• We don't have easy and accurate ways to test pets for TB exposure and shedding. In people, sputum cultures are tested by having people spit in a cup. Getting a sample like that is obviously difficult in dogs. Collecting a good sample for testing is much more involved in pets and not amenable to routine testing (for research or monitoring).
• We don't know for how long to treat a pet with TB, or which drugs are optimal for use.

Treatment might be reasonable when there is an animal with mild disease (or no signs of disease), when the animal was infected from a household contact (meaning that some degree of TB exposure has already occurred in the household and the dog would probably only be a secondary source of exposure), when there are committed owners who are willing to embark on time consuming and expensive treatment, when owners are able to keep the dog away from other animals and people during the treatment period, and when there is an understanding that treatment may not work.

When might treatment not be a good idea?

• When the animal is shedding the TB bacterium in respiratory secretions.
• When the owners cannot afford prolonged and expensive treatment and monitoring.
• When the owners cannot be relied on the administer every dose of medication and make every required follow-up appointment.
• When owners cannot be relied on to keep the dog away from other dogs and animals (and people) during the treatment period (or at least during the initial period).
• When there are high-risk people in the household, such as people with HIV.
• When serious disease is present, such that the chances of recovery are low.

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If an unvaccinated person is exposed to rabies, the protocol is very clear: the person receives a single dose of anti-rabies antibody and a series of four rabies vaccines over a few weeks.

If an unvaccinated dog is exposed to rabies, the typical requirement is a strict six-month quarantine (with rabies vaccination one month into quarantine or one month before the end of quarantine) or prompt euthanasia.

Why? There has been only limited investigation of rabies post-exposure treatments in dogs. Ineffective post-exposure treatment could put the people around an exposed dog at risk of rabies exposure themselves.  In the absence of convincing evidence, public health concerns trump animal issues.

A recent study published in the Journal of the American Veterinary Medical Association (Wilson et al 2010) sheds some more light on the topic. The authors reviewed records from rabies-exposed animals in Texas from 2000-2009, where a different post-exposure protocol is used for animals.  In Texas, exposed unvaccinated animals are either:

• immediately euthanized, OR
• immediately vaccinated, kept in strict isolation for 90 days and given rabies vaccine boosters during the 3rd and 8th week of quarantine.

The authors reviewed the records of 1014 animals (769 dogs, 126 cats, 72 horses, 39 cattle, 3 sheep, 4 goats and 1 llama) that were treated with this modified protocol after exposure to another animal that was confirmed to be rabid.

None of the treated animals developed rabies.

An important issue to bear in mind is whether the animals in the report were actually exposed to the rabies virus itself, not just a rabid animal. There's no way to prove that any were actually exposed to the virus, however 29% had what was considered "direct exposure," and a further 38% had "probable exposure." Presumably, not all the animals were actually exposed, but even so, because they looked at so many animals, it provides more convincing evidence that the protocol is effective for preventing rabies. The only definitive way to figure it out would be to experimentally infect animals with rabies and then see if the post-exposure treatment prevents them from developing disease, something that is unlikely to be done for many reasons.

Immediate vaccination may be a key component of this protocol. Previous reports of post-exposure treatment failure have been cases where there was a relatively long interval (e.g. a couple of weeks) from rabies exposure to first vaccination. By that time, it's possible that the infection is too advanced, particularly since the typical incubation period for rabies in dogs is 21-60 days.

The Texas post-exposure protocol makes sense. It appears to be effective and requires a shorter quarantine period. Those are both important factors, and make post-exposure treatment a more viable option.

However, while this study provides evidence that this protocol may be effective, it doesn't mean everyone can just start using it. Regional laws regarding rabies exposure supercede these results, and unless the rules are changed, this approach may not be an option. Hopefully, regulatory officials will look at the results of this study and Texas' experience, and think about modifying their own protocols.

At the end of the day, however, it's still much better to have your animal properly vaccinated against rabies so that post-exposure treatment or quarantine isn't needed. Vaccination isn't 100% effective, but it's very good overall, and the mandated response to exposure of a vaccinated animal is much easier (on both the animal and owner) than for an unvaccinated animal.

(click image for source)

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Tegus are large South American lizards that are sometimes kept as pets. As with other reptiles, Salmonella is a concern, as highlighted by a recent study in the journal Zoonoses and Public Health (Maciel et al. 2010). In that study, the authors tested feces of 30 captive-born tegus. From the first round of samples, they isolated various types of Salmonella from 87% of the animals. They collected a second fecal sample from the 4 tegus that were initially negative, and found Salmonella in feces of all of them. 

It's not particularly surprising to find Salmonella in tegus, just like in other reptiles. The fact that it wasn't too hard for the authors to find this important bacterium in all of the reptiles highlights the public health concerns regarding reptiles and Salmonella. Further, they showed (as has been shown with other reptiles like snakes) that Salmonella can be shed intermittently, so a negative culture doesn't mean the animal is truly Salmonella-free.

Reptiles can make good pets, but they are accompanied by an increased degree of risk with regard to infectious diseases. They are not recommended for households with children less than five years of age, elderly persons, pregnant women or people with compromised immune systems. In low-risk households (i.e. households without people in these categories), the risk can be reduced (though not eliminated) by basic common sense practices, particularly close attention to handwashing after touching the animal or its environment, and preventing the animal from roaming around the house.

Image from http://ns3.powerblogs.com/my_pet_tegu/

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Bomb threat? Yes.

Heart attacks? Sure.

Mechanical problems? Absolutely.

Aggressive passengers? Yes.

But a 12-pound dog? Apparently so.

"Mandy," a Manchester terrier, has joined the exclusive club of causes of airplane diversions.

Mandy and her owner were flying from Newark to Phoenix on a US Airways flight. The dog was sedated and in an airline-approved cage under the seat, as per airline policy. So far, so good.

Then the dog started to become agitated. One report suggests it was because the sedation was wearing off. Whatever the cause, the owner tried to take the agitated dog out of the protective confines of its cage, into a noisy, crowded and potentially frightening new environment. Not surprisingly, when you take a dog coming out of sedation (and perhaps not completely aware of what's going on) and put it in a unfamiliar and confusing environment, bad things can happen.

In this case, it resulted in the dog biting the passenger in the seat next to the owner (who was trying to help calm down the dog). The dog then got loose and ran up and down the aisle of the plane, barking. A flight attendant who tried to grab the dog was also bitten.

The bites were minor, but the pilot decided to divert the flight to Pittsburgh so the bite victims could be treated (and presumably to get the dog off the plane before it bit more people). The people who were bitten eventually got back on board and continued the flight. However, Mandy and her owner did not, as "separate transportation" was arranged for them.

There's no information in the reports I've seen about the dog's rabies vaccination status, something that was hopefully queried by medical personnel. There's also no information about whether any action will be taken against the dog's owner. If the airline (and/or passengers) wanted to, I imagine a lawsuit could easily follow (especially given the litigious nature of US society). They might win, too, since the dog's owner deliberately broke clear rules that say the dog must remain in the carrier at all times. As a result of her action:

• Two people were injured.
• Medical costs were incurred.
• The plane had to be diverted, probably resulting in a large cost to the airline for additional landing fees, fuel, personnel time, and perhaps the need to move flight personnel or postpone flights because of the diversion. (I'd love to know an estimate of what such a diversion actually costs.)
• 122 passengers were inconvenienced and might have incurred costs from the delay as well.

...all for something that could have been avoided by leaving the dog in its cage.

(click image for source)

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A dead otter was found floating in a pond in Florida near the site of a recent otter attack that was captured on video. Testing confirmed that the animal was rabid. It's impossible to determine whether this is the same otter that attacked the teenager in Boca Raton last week, but it's likely, and shows that rabies post-exposure treatment of the victim was a good decision.

Numerous rabid otters have been identified in Florida in recent years. I haven't seen any information about the viral types that have been involved or how it is thought that otters are becoming infected. Regardless, these incidents should be a reminder to stay away from wildlife, and to consider rabies exposure any time someone has been bitten by a wild mammal.

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A teenager who was filming an otter he spied in a pond now knows more about rabies than he probably ever wanted. The 19-year-old shot the video from the bank of a pond, watching the otter innocently swimming around. After a brief stare-down, the otter did another quick swim, then ran onto shore and attacked!  And it was all caught on camera and displayed to the world via YouTube.

This is the third recently-reported otter attack in the area. This type of behaviour obviously isn't normal, and rabies has to be a concern. Rabies has been previously identified in marauding otters in Florida, and since this otter got away, you have to assume that it was rabid. Accordingly, the victim is undergoing rabies post-exposure treatment.

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Pardon my straying from the zoonotic disease realm, but here's a little light reading... (for the pdf version with images click here).

Medical Mysteries of the 100-Acre Wood

Children around the world have been entertained by activities in the 100-acre-wood for decades. But at what cost to the animals? What kind of example is this setting given the obvious medical and ethical problems present in these animals? As protectors of animal health and welfare, and fully cognizant of the ethical requirements put upon us by the Veterinarian’s Oath, we feel bound to address these issues and call for immediate action.

Winnie the Pooh may be a lovable creature, but he clearly has numerous health problems. Despite being born in 1926, Winnie the Pooh appears not to have grown to adult height. This stunted size may be the result of a primary growth hormone deficiency, but we suspect that it is solely the result of inadequate nutrition. His body mass index is excessive, in large part from his inadequate diet. A diet based solely on honey is inadequate for a growing bear. The caloric density is a main factor in this animal’s obesity. As well, it is virtually guaranteed that Pooh has, or will soon have, numerous nutritional deficiencies based on this diet. Pooh also seems rather "slow on the uptake" which may be the result of inadequate omega-3 fatty acid intake. Unlike many other bears feasting on wild salmon and other sources of these important fatty acids, Pooh’s omega-3-deficient diet has not provided him with the neuroprotective and developmental benefits that omega-3s provide. Sadly, this is irreversible and Pooh will never be able to obtain his true genetic capacity for intelligence. Despite the irreversible nature of his improper brain development, there are other areas that can be improved and his diet must be addressed immediately. This may not be easy, given decades of inadequate diet and conditioning to only eat honey. While some may recommend the use of mirtazapine to stimulate his appetite along with provision of a normal diet, we disagree and believe that a more natural approach involving complete restriction of honey along with providing an adequate diet will be successful. Use of mirtazapine may be unnecessary, particularly once hunger sets in. Further, this would be an off-label use of the drug and we have little confidence in available ursine dosing data. There is always concern regarding the metabolic efforts of dietary restriction in overweight animals, but we are unable to find any published reports of fatty liver syndrome in obese bears being weaned from a honey-only diet, so this absence of published evidence clearly indicates that this is a completely safe approach. We do, however, recommend a complete hepatic evaluation prior to feed restriction because of the marked yellow pigmentation of this bear.

Eeyore clearly has a significant undiagnosed metabolic disease, given his body condition, poor muscle mass and lethargy. While equine metabolic syndrome has been poorly investigated in donkeys, it is a likely explanation for the excessive body condition. The slow purposeful movements exhibited by this animal also suggest the presence of a primary muscular disorder such as polysaccharide storage myopathy. At a minimum, muscle biopsy is indicated to determine the cause of his unwillingness to move beyond a crawl. Certainly, the slow movement and vocalization could be the result of a brain lesion but, sadly, Eeyore’s girth is too excessive for him to fit into existing MRI or CT scanners. Only with proper control of his metabolic disease and a good nutritional program will there be any ability to diagnose any cerebral component. Blind brain biopsy is not recommended due to the invasive nature of this diagnostic test and the rather low likelihood of actually identifying brain tissue in a donkey.

At the opposite end of the spectrum is Tigger, the hyperactive tiger whose incessant jumping and twitching likely indicates the presence of a cerebellar disorder. In the absence of advanced imaging (which would obviously require travel beyond the 100-acre-wood) one must make a presumptive diagnosis of cerebellar hypoplasia from fetal infection with feline panleukopenia virus. Unfortunately, there are no therapeutic options and there is a grave prognosis for clinical improvement. He must also have an additional neurological abnormality affecting his cerebral cortex since he has repeatedly shown an unwillingness to recognize readily available food sources, most notably a young pig.

Roo is an active young kangaroo. While his excitable, bouncy nature may simply be the exuberance of youth, we are concerned about the sustained energy. This concern is heightened by the fact that all images of this animal show profound papillary dilation to the point that his eyes appear completely black. This sign clearly indicates the potential for illicit drug exposure. Drug testing is required. His mother, Kanga, appears to be a loving, caring mother, with no apparent health problems. Despite this, she must be investigated as a potential source of Roo’s drug exposure because her attitude seems too persistently cheerful for someone spending all her time around a hyperactive youngster.

                Piglet’s most obvious abnormality involves vocalization. There are many potential causes of vocalization abnormalities in pigs, including behavioural and neurological etiologies. Piglet appears to be the only piglet left from his litter, so congenital or neonatal infection that killed his siblings and left him with a serious stutter must be considered. We are hesitant to speculate about specific causes or the potential food safety risk. CT or MRI would be required to explore this further, but it is questionable whether this is justifiable given the cost involved for a pig. Further, consumer concerns about irradiated meat may preclude CT scanning.

Rabbit, while exhibiting classical signs of dominance, does not manifest his behaviour in bites or other serious outcomes. His dominating personality is more directed at controlling the daily activities of his cohorts, without obvious negative impacts. That, combined with limited pharmacokinetic or safety data for drugs like fluoxetine (Prozac) in rabbits lead us to recommend no treatment for this disorder. However, given the high prevalence of Encephalitozoon cuniculi shedding by rabbits, we must assume that he is carrying this animal and human pathogen in his kidneys, and ensure that contamination of the environment with urine is avoided. Concerningly, there consistently appears to be a dearth of hand hygiene opportunities in the 100-acre-wood, with few sinks and complete absence of hand sanitizers. This infection control deficiency must be addressed to contain the multitude of pathogens that appear to be present in this toxic environment.

And finally, on to Christopher Robin. While a minor, Mr. Robin is clearly the caretaker of this ragtag group of animals and certainly bears (pun intended) responsibility for their health and welfare. His obvious failure to provide adequate veterinary care is of significant concern and should result in immediate investigation. The potential for Christopher Robin to be the source, intentional or otherwise, of Roo’s illicit drug exposure raises numerous additional concerns. At a minimum, thorough veterinary examination of all animals and review of animal management practices should be mandated by regional authorities to ensure the health and welfare of these animals, as well as children around the world that are learning from Christopher Robin’s example.

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