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)

Out of 678 nasal swabs (taken from horses on over 500 premises), only 4 (0.6%) were positive for MRSA.  That's good to see, as it's very easy for MRSA to spread in a horse population "under the radar," because colonized horses do not have any outward signs that they are carrying the pathogen.  The overall low prevalence in the community setting is similar to previous community studies in the UK and other areas.  Out of 650 fecal samples, 452 (72.2%) were positive for an E. coli that was resistant to at least one antimicrobial.  That's not too surprising.  The bigger concern is that 233 (37.6% - over one third of all horses tested) samples contained multidrug-resistant E.coli (defined in this study as resistance to more than three antimicrobial classes) and 42 (6.3%) samples contained an E. coli that produced an extended-spectrum beta-lactamase (ESBL).  ESBLs are particularly problematic because they can be relatively easily transferred between bacteria, they confer resistance to a large number of commonly used antimicrobials in the beta-lactam class (which includes penicillins and cephalosporins), and are frequently associated with genes that confer resistance to other antimicrobial classes as well.  Bacteria that produce ESBLs are a significant problem in human medicine and have been reported to cause infection in horses as well.

The second part of the study used information collected from questionnaires filled out by the horse owners to try to determine risk factors that affected the odds of a particular horse shedding antimicrobial-resistant E. coli.  They used some pretty heavy-duty statistical analysis because they were looking at so many factors and different outcomes, and any time that happens you have to take the final numbers with a grain of salt. Nonetheless, the results can help point the way for future studies to help determine which factors may have the biggest impact on the risk. The authors found recent hospitalization and veterinary treatment for various conditions over the last six months were associated with higher odds of shedding multidrug-resistant strains of E. coli, and the type of farm/facility also affected the odds.  In addition, having a recently hospitalized horse on the premises (among other things) increased the odds of a horse shedding ESBL E.coli.

What does all this mean for the average horse owner?  The results really aren't new or startling.  We already know that antimicrobial resistance is a growing problem in equine medicine, as it is in veterinary and human medicine in general, and this is one more set of studies that provides evidence to that effect.  I have no doubt that if a similar study was performed in North America the same kinds of resistant bacteria would be detected, although the numbers may vary somewhat one way or another.  The second part of the study also re-emphasize the role that antimicrobial use plays in promoting development of and selection for resistant bacteria, and the potential for the treatment of certain horses to affect the microbes being carried and shed by the animals around them.  In the end, it comes down to being responsible about how we use antimicrobials in order to curb the development of resistance, so that these important drugs remain effective for treating serious infections in the future.  This applies equally to their use in people and animals of all kinds.

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.

On August 13 there was an unconfirmed report of a case of West Nile in a horse at Woodbine Racetrack, just north of Toronto.  No additional details have been forthcoming regarding the severity of the infection or the status of the horse, if WNV infection has in fact been diagnosed.  Nonetheless, the Ontario HBPA is urging horse owners to ensure the vaccination status of their animals for West Nile is up-to-date.  Unfortunately, if horses are not already vaccinated at this point, even vaccinating them immediately may still leave them susceptible to virus for the next few weeks until they are able to fully respond to the vaccine.  This news follows close on the heels of news reports regarding increased numbers of WNV-positive mosquito pools in various regions north of Toronto, and thus is not altogether surprising.

The first case of West Nile in a human in New Jersey was recently diagnosed in a man from Mercer County.  Again, no additional details about the severity of the infection or the man's condition are available, but the public is once again being urged to protect themselves against mosquitoes by wearing long sleeves and pants, using insect repellant, and eliminating standing water in which mosquitoes may breed on their property.  Elsewhere the death on August 14 of a four-year-old girl in New York from infection with EEE has been reported.  She is the fifth person in New York state to die from the disease in 40 years.  The girl first began showing signs of infection earlier this month, but the diagnosis of EEE infection was only reached last week.  EEE has a high mortality rate in humans as well as horses.  Just as infection in animals can act as sentinel indicators for disease risk in humans, these human cases indicate that WNV and EEE are active in these respective areas, and humans and horses alike are at risk of infection.  Mosquito avoidance can help protect both, and in addition timely vaccination of horses can help decrease the risk of disease.

This Worms & Germs blog entry was originally posted on equIDblog on 17-Aug-11.

On August 13 there was an unconfirmed report of a case of West Nile in a horse at Woodbine Racetrack, just north of Toronto.  No additional details have been forthcoming regarding the severity of the infection or the status of the horse, if WNV infection has in fact been diagnosed.  Nonetheless, the Ontario HBPA is urging horse owners to ensure the vaccination status of their animals for West Nile is up-to-date.  Unfortunately, if horses are not already vaccinated at this point, even vaccinating them immediately may still leave them susceptible to virus for the next few weeks until they are able to fully respond to the vaccine.  This news follows close on the heels of news reports regarding increased numbers of WNV-positive mosquito pools in various regions north of Toronto, and thus is not altogether surprising.

The first case of West Nile in a human in New Jersey was recently diagnosed in a man from Mercer County.  Again, no additional details about the severity of the infection or the man's condition are available, but the public is once again being urged to protect themselves against mosquitoes by wearing long sleeves and pants, using insect repellant, and eliminating standing water in which mosquitoes may breed on their property.  Elsewhere the death on August 14 of a four-year-old girl in New York from infection with EEE has been reported.  She is the fifth person in New York state to die from the disease in 40 years.  The girl first began showing signs of infection earlier this month, but the diagnosis of EEE infection was only reached last week.  EEE has a high mortality rate in humans as well as horses.  Just as infection in animals can act as sentinel indicators for disease risk in humans, these human cases indicate that WNV and EEE are active in these respective areas, and humans and horses alike are at risk of infection.  Mosquito avoidance can help protect both, and in addition timely vaccination of horses can help decrease the risk of disease.

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)

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

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

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

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

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

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

It is unclear to whom the dogs belonged, as the mother and father of the baby were sharing the house with two other people.  The baby's father (who was not home at the time of the attack) said that the dogs had been around ever since the baby was born and had never posed a problem.  The dogs were not normally aggressive and "when strangers came to the door, they didn't even bark."  He said "there was no sign that this could happen."

Dog bites are always bad, but in the case of small children in particular they can even be fatal.  According to Statistics Canada, since 1990 there have been 28 fatal dog attacks in Canada, and 85% of those killed were children under the age of 12.

Dog bites often occur when people don't know how to behave around a dog, and dogs may bite out of aggression, fear, or rough play.  A three-week-old baby strapped to a car seat would pose little threat to a Husky, and unfortunately we will likely never know what brought on the attack.  Parents and family members need to realize that a new baby is a big adjustment for everyone in the household - and that includes pets.  A dog that is normally "as good as gold" may react very differently to a small, wriggling, strange-smelling, crying baby that suddenly takes over part of the animal's home "territory."  It is very important that pets and babies be introduced very carefully and slowly, and they should always be supervised.  Dr. Enid Styles, a veterinarian and behaviourist, makes some very important points:

...Styles said it is possible the animal might have been startled by the child's crying or the baby might have been caught in the middle of a fight between the dogs.

In any case, a child should never be left unattended around dogs...

"Supervision needs to mean, really, that you are between your dog and your child," she said. "You can't be just on the other side of the room."

Both Huskies have been seized by the Humane Society, and tests will be done to to confirm which of the animals was responsible for the attack and whether it was suffering from any problems, such as rabies (which presumably means the dog will be quarantined for 10 days).  It is likely that the dog responsible will be euthanized.

Photo source: www.cbc.ca

This morning the Toronto Star published an article about the intended euthanasia of 350 animals at a humane society in Newmarket due to an ongoing ringworm outbreak.  This was quickly followed by another article about the same event that gave a few more details, including some comments from the OSPCA chief executive officer Kate MacDonald, who confirmed that the euthanasias had begun.  A "very aggressive strain" of ringworm and "human error" (related to a breakdown in protocols) are currently being blamed for this morning's actions.  A lot of people are (understandably) very upset.  No one ever wants to see an infectious disease outbreak come to something like this.

I’m hesitant to comment too much at this stage, because we still don’t have all the facts - apparently even the duration of the outbreak is unknown.  No one has said if all 350 animals are infected (or what percentage of them are), nor how many other animals are present at the shelter. We also don’t know what’s already been tried in terms of controlling the outbreak.

A few facts about ringworm (dermatophytosis) that people need to remember:

• Ringworm is a skin infection that can be caused by several species of fungi.  It is not a "worm" at all.  It is also very easily transmitted by direct or indirect contact with infected animals - their fur, their cages, their blankets, or anything else that may be contaminated with infected skin cells or hair.  Such infectious material can even be spread over short distances (e.g. room to room) in dust that is stirred up into the air.
• Ringworm is transmissible to people, so with a large outbreak there are also issues with staff safety, and concerns with adopting out infected animals.  For most people ringworm infection may cause itchy, uncomfortable skin lesions, but for higher-risk people (e.g. very young children, the elderly or immunosuppressed individuals) the infection can be much more serious.
• There are also a lot of animals (particularly cats) that carry ringworm without showing any signs of infection. If the Newmarket shelter has 350 animals with clinical signs of ringworm (a detail about which we have no information right now), that’s pretty bad, but even the animals who don't appear to be infected may be carrying the fungus and could spread it to others.
• Crowding, close contact and warm, humid environments are all factors that increase the risk of ringworm transmission. These are also all factors that are very hard to control in a crowded animal shelter.
• Ringworm is treatable, but it is not cheap or easy. Animals typically require systemic therapy (usually oral medication, which can be very expensive particularly in large dogs) as well as whole-body topical therapy (e.g. dips, shampoos, sprays), and they need to be treated for several weeks. Decontamination of the environment at the same time is critical to prevent reinfection.

Cleaning up a ringworm outbreak at a shelter with at least 350 animals is no small undertaking.  The second article in the Star also describes personnel at the shelter this morning wearing "white hazardous material suits, latex gloves and plastic covers over their shoes", which would be considered reasonable precautions for entering a highly contaminated environment.

I'm sure we'll hear more about this in the days to come, and hopefully that will include more details about why the mass euthanasia was deemed necessary by the OSPCA.

For more more information about ringworm, download the information sheet from the Worms & Germs Resources page, or check out our archives.

Photo source: yorkregion.ontariospca.ca via www.thestar.com

Hand hygiene is one of the most important aspects of controlling infection in human hospitals, but that’s certainly not the only place where it can be beneficial. It is also very important in veterinary hospitals, to help prevent the spread of infection between animals, whether they’re sick or they’ve just had surgery. Here on the Worms & Germs blog, we also talk a lot about using proper hand hygiene to help prevent the spread of zoonotic pathogens from pets to people. Even at home, just like in hospitals, our hands are one of the most common ways bacteria and viruses move from one surface to another, from one person to another, and from just about anything into our mouths (either directly or via our food). Dirt on your hands is easy to see, and it makes it easy to remember to wash your hands. The bigger concern is the microscopic amounts of dirt and germs on your hands that you can’t see, and the best way to take care of that is really to make hand hygiene part of your routine. Make it something that just naturally goes along with playing with your pet, or cleaning the cat’s litterbox, or poop-scooping after your dog. Although most of the time it may not be a matter of saving lives, it’s certainly a matter of saving people from being sick. Make hand hygiene a habit, and don’t just do it for yourself – do it for all the people (and pets!) you live with and interact with everyday.
 

1. Consuming a commercial or homemade raw diet, a homemade cooked diet, or raw meat and eggs, increases a pet dog’s risk of carrying Salmonella.

Raw is raw, and by now we're hoping that people are getting the message that raw is contaminated, whether we're talking about a commercial or homemade raw diet, or feeding any raw animal products (e.g. meat, eggs).  The fact that homemade cooked diets also made the list could be explained by the fact that in order to make such a diet, owners still need to start with the raw ingredients.  Handling and cooking raw meat and animal products for your pet should be done with the same precautions as handling and cooking raw meat for yourself or your family.  If these homemade diets were not cooked as thoroughly as they should have been, or if there was contamination of the dog's dishes with raw product, that could explain the association with Salmonella shedding.  Although traditional commercial diets can also be contaminated with pathogens (usually after processing), the risk with these is much lower.

2. Testing multiple consecutive whole fecal samples greatly improves Salmonella recovery in dogs.

This is no great surprise either.  Dogs (and many other species) shed Salmonella intermittently, so not every fecal sample from a Salmonella-positive dog is going to yield Salmonella on culture.  The authors tested five daily fecal samples from each dog.  Based on this study, the sensitivity of testing a single fecal sample in a dog (i.e. the likelihood that a Salmonella-positive dog will test positive on one fecal sample) was only 35.5%.  That means almost two-thirds of positive dogs will be missed if they're only tested once.  The take-home message on this point is that in order to find Salmonella in a healthy pet dog, multiple samples should be tested.

3. Having multiple dogs in a household, using probiotics and contact with livestock are important potential risk factors that need to be investigated further.

These were factors that were flagged by the authors for future investigation, because at first they seemed to be associated with Salmonella shedding in the dogs, but when the feeding of raw diets was taken into account the associations were no longer significant.  A larger study, or one using a different design, will be needed to help tease apart the potential effects of these factors from feeding practices.

The bottom line: Feeding raw is risky business.  Some people swear by the benefits of raw diets, but the objective evidence is lacking.  There is clear evidence of the risks.  In my mind, the potential up-side simply cannot outweigh the well-established down-side of feeding raw diets to pets.

The researchers collected feces from 52 active raccoon latrines around the city and from 114 "nuisance" raccoons that were caught, euthanised and submitted for necropsy to the local lab. Interestingly, the vast majority of latrines and nuissance raccoons were found close to the two major rivers that run through Winnipeg. Half (50%) of all the latrines were positive for roundworm eggs on at least one sample (out of a possible 3). Among the necropsied raccoons, 61/114 (53.5%) were positive for roundworms. Adult raccoons were almost four times as likely to carry roundworms than juveniles (which is in contrast to a previous study that found juveniles more likely to be infected), and bigger raccoons (over 2.75 kg) were more than seven times as likely to carry roundworms compared to smaller animals. Although there are regions where the prevalence of B. procyonis s reported to be very low, Winnipeg, like many other regions of North America, has joined the ranks of those where the prevalence is high and the public needs to be aware of the associated risks.

The most severe zoonotic disease caused by B. procyonis is called neural larval migrans (NLM), which results from migration of parasite larvae through the central nervous system (i.e. brain). Two of the reasons this is much more of a concern with raccoon roundworms (Baylisascaris) compared to dog and cat roundworms (Toxocara) are:

1) A massive number of parasite eggs are passed in the feces of infected raccoons (which typically have a very high burden of adult worms). Coupled with the fact that the eggs are further concentrated in areas where many raccoons defecate (latrines), this can lead to heavy exposure of people (or animals) who come in contact with the soil in these areas, which greatly increases the risk of infection.

2) The larvae of B. procyonis are very active migrators, and they get bigger as they migrate through tissues - much bigger than Toxocara larvae ever get, which means they also tend to cause a lot more damage before they're finally (if ever) trapped or killed by the body's immune response.

Natural infection of dogs living in the same areas as raccoons has been found - it's not common, but it appears to occur frequently enough to warrant noting. Dogs and cats can also be infected by their own species of roundworms, which will also result in parasite eggs being shed in the feces. It's important to have your veterinarian perform a fecal examination for your pet on a regular basis so any parasite infestations (roundworm or other) can be treated.

Dogs and cats may also be susceptible to larval migrans in the same manner as people (and the animals at the zoo in Winnipeg) if they are exposed to high numbers of infectious eggs. Remember that roundworm eggs must be swallowed in order for infection of any kind to occur, so good hand hygiene and avoiding soil contamination of food are key to preventing transmission. Also, do not allow your pet to dig or play in an area where raccoons defecate (preventing direct contact between your dog and raccoons should go without saying!).  And of course, feces of any kind (and from any species) should be treated as infectious material, and handled with appropriate precautions.

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

Anyone who has read anything about food safety hopefully knows that raw meat can potentially be (and usually is) contaminated with many different pathogens - that's the biggest reason why observing proper cooking times and temperatures is so important.  Raw poultry in particular should basically be treated like it's contaminated with Salmonella and/or Campylobacter until proven otherwise.  You can just imagine the field day that these bacteria could have in a nice warm, wet bathtub - it's just the way they like it, and it's exactly what we try to avoid in the kitchen, where food is ideally kept either nice and cold or nice and hot in order to prevent (or at least minimize) bacterial growth.  Then of all things to put young children in this veritable cesspool of bacteria - turkey and all - it's just a gastrointestinal disaster waiting to happen.  You also needs to consider what the turkey could become contaminated with sitting in bathwater.  Even children who don't have diarrhea can be shedding intestinal pathogens - human pathogens which are obviously transmissible to other people.  If you really cooked that bird well (maybe deep-fried it) I suppose that should ultimatley eliminate any surface contamination anyway, but I don't think I'd be able to get past the "ick" factor.  Don't throw the baby out with the bathwater, but of there's a turkey in there (as far as I'm concerned) that can go.

I realize this is primarily a food safety issue, but it made me think about what else this person (or others) may put in a bathtub.  In previous posts in which we've talked about reptiles kept as pets (all of which should be treated as Salmonella carriers), we've mentioned that ideally (if they need a bath) they should be bathed in their own designated container (like a big rubbermaid) and not in the bathtub.  If there is no other option and the bathtub must be used, it should be thoroughly cleaned and properly disinfected (keeping contact-time with the disinfectant in mind) before it is used again by a person (especially children). 

Ideally the same precautions should be taken if you bathe a dog in the bathtub, but the risks are not as high as with reptiles (unless the dog is very dirty, has skin lesions, or has (or recently had) diarrhea).  We've talked about the limited risks of allowing dogs in backyard swimming pools (but of course there is even less chlorine in bath water).  I hope no one ever bathes their dog with their kids - we could debate the risks, which likely aren't high anyway, but in the end the risk is simply unnecessary.  The pool is one thing, but there's no reason for a dog to be in the tub at the same time as the kids (and really, how clean are the kids going to get with a dirty dog in the tub?).  If you're trying to save water you can always throw the dog in after the kids are out.

If you're attempting to bathe a cat in the tub... well, based on most feline behaviour I'd say your primary risks are bites and scratches more than enteric bacteria and parasites.  Proceed at your own risk!

A happy (and hopefully healthy) American Thanksgiving to all of our US readers!

Responsible use of antibiotics can help stop resistant bacteria from developing and help keep antibiotics effective for the use of future generations.  Successful national public awareness campaigns are already resulting in more rational use of antibiotics and a reduction in levels of antibiotic resistance in Europe.

Responsible use of antibiotics includes use in people and in animals.  Here are some of the things you can do to help with regard to antibiotic use in your pets:

• Only give your pet antibiotics if directed to do so by your veterinarian.
• Make sure your pet gets the full dose of medication at the correct time(s) of day.  If you are having problems getting your pet to swallow pills or take medication, contact your veterinarian as soon as possible.  Your veterinarian may be able to give you advice on some "tricks" for getting your pet to take the medication, or sometimes the medication can be provided in a different form (e.g. a liquid instead of a pill).
• Always ensure your pet finishes the entire prescription.  There should be no leftover pills or medication.  Do not stop giving your pet the antibiotics just because it looks/acts like its feeling better.  This is a common mistake that can have disasterous consequences!  You should NEVER "save a few pills for the next time."
• Never give your pet antibiotics that were prescribed for you or any other person, whether they are expired or not.

This is not a reason to panic.  No one can get the flu from eating a properly-cooked Thanksgiving turkey (nor from any other type of properly-cooked turkey).  The producer has voluntarily (and very responsibly) quarantined the affected flock, and no birds or eggs have left the facility.  There is no risk to the food chain.

Pigs can be infected by human, pig and bird flu viruses, and multiple infections can result in viruses trading genes and producing new viruses that can infect more species.  So it's not too surprising that H1N1can infect people, pigs and now birds as well.  This incident serves as an important reminder that we need to remain diligent about infection control and hygiene, even around animals.  It's highly unlikely that these turkeys had contact with infected pigs - most likely the virus was spread to this flock by a person.  Poultry producers may therefore need to consider getting vaccinated for H1N1 flu not only to protect themselves, but also their flocks, and anyone who may have the flu should definitely stay off these farms.  Hopefully the virus does not become established in wild bird populations (like H5N1 has in some areas), as this would make it much harder to control.

Recommendations for avoiding the flu (H1N1 or other) remain the same:

• Wash your hands and/or use alcohol-based hand sanitizer
• Sneeze into your elbow
• Disinfect commonly touched surfaces
• Stay home if you are sick
• Get vaccinated!

Prevention of lepto in dogs, as with most diseases, is preferred to trying to treat sick animals.  The best way to avoid the bacterium is to keep your dog out of areas where infected wildlife may urinate frequently, particularly out in the bush.  But of course, skunks and raccoons can be found as close as the backyard as well, so even in the city the risk isn't zero.

If your dog does frequently go into the bush and is at increased risk for leptospirosis, hopefully you've already discussed vaccination with your veterinarian.  While the vaccine available doesn't protect against all types of lepto, it does help protect against the most common ones - in Ontario, these are believed to be the lepto serovars grippotyphosa and pomona.  We also received the following question from a reader the other day:

"Should a dog who has shown positive for early stages of kidney disease be vaccinated against leptospirosis?  Can the vaccine accelerate the illness to acute renal failure?"

I can see where the question comes from, but the simple answer to the second part of the question is no.  Although the infection can certainly affect the animal's renal function (and can push even healthy dogs into renal failure if it is severe), the vaccine works on the dog's immune system and does not affect the kidneys directly.  The answer to the first part of the question is, of course, much more complicated, and depends on many other factors including the dog's overall health status, lifestyle and other risk factors, and vaccination history.  The decision about whether or not to vaccinate your dog should be discussed on an individual basis with your veterinarian.

More information about leptospirosis is available on the Worms & Germs Resources page and in our archives.

Image: Scanning electron micrograph of Leptospira sp. bacteria (source: CDC Public Health Image Library ID#138))

Q fever is caused by a highly infectious organism called Coxiella burnetii.  The organism can be carried by many different animals, but particular sheep and goats, and sometimes cattle.  Most of the time it does not cause a problem in these species, but it has been linked to abortions and abortion storms (i.e. when many animals in the herd abort in a short period of time).  It can be shed in manure, urine and milk, but the largest numbers of organisms are found in birth fluids and tissues (e.g. aborted fetuses, placentae).  When the tissues and fluid dry out, the organism can be stirred up into the air over short distances in dust.  Humans are highly susceptible to C. burnetii, and inhaling even a single organism can cause infection.  Most of the time people who get sick have signs very similar to the flu, but severe pneumonia and liver disease can develop in a small number of cases.

A definitive link between sheep and goats and the Q fever outbreak in people in the Netherlands has not yet been established, but it is highly suspected that many of the cases are associated with infected goats (and some sheep).  In the last two years numerous outbreaks of Q fever have been reported on dairy goat farms and one dairy sheep farm in the Netherlands.  This has lead to a cooperative arrangement between the Dutch agricultural ministry and the Dutch public health ministry - these two goverment branches have come together to help cover the costs of vaccinating sheep and goat herds in the country, in order to help stem the tide of disease and ultimately prevent more human cases.  This is a great example of the "one medicine" concept, whereby groups on both the human health and agricultural/animal health sides are working together on this problem.

Manditory vacciation is now required for sheep and goats on larger farms in the hardest-hit areas, as well as any farms reporting any cases of Q fever since 2005, and any sheep or goats that have a "public function" (e.g. petting zoo animals or occupational therapy farms).  It is very important that this last group is included under the manditory vaccination, as these animals have a large amount of contact with people.  Steps have also been taken to improve hygiene, restrict spreading manure from sheep and goats, restrict visitors to infected farms, and to make abortion storms on sheep and goat farms reportable, so they can be investigated for Q fever.  It will be interesting to see how effective these measures are at controling the outbreak in 2009.

More information on Q fever can be found in our archives.

A couple of months back, Oprah adopted two cocker spaniel puppies from a shelter in Chicago. Unfortunately, within two weeks they both came down with parvovirus infection and had to be hospitalized. I'm sure both dogs received top-of-the-line care with no expense spared, but even so one of the puppies died. The other puppy came very close to dying as well, but happily she apparently has now recovered completely and is doing just fine (or quite likely better than fine, considering who her new owner is!).

Oprah also mentioned how one of her other dogs, Solomon, also suffered from a parvo infection years ago, but that dog was over a year old when he became ill. It's actually quite unusual for any dog to get parvo beyond one year of age - most adult dogs are not affected by the virus, unless perhaps their immune system is compromised for some reason.

These stories bring up a few interesting points to ponder:

It's great to adopt an animal from a shelter and give a homeless animal a home. It is an act of great kindness that I don't want to take anything away from in the least. However, it's important to realize that you never know what shelter dogs may be carrying, nor how well vaccinated they are.

• Even if the animals are vaccinated once at the shelter, the protective effect may be less than ideal if a properly timed vaccination series is not completed.
• In this case the pups may have been exposed to parvo after leaving the shelter, but they could have just as easily been exposed at the shelter, which begs the question of what else might they have been carrying? Bacterial pathogens such as Salmonella and Campylobacter are also particularly common in young dogs and cats (even healthy ones), and these are potentially zoonotic agents.

Young animals, particularly from shelters, are higher risk in terms of the infectious diseases they can carry and transmit. That doesn't mean they shouldn't be adopted, but it does mean taking some extra precautions for the first several weeks they're in their new home. These include being very diligent about controlling stool contamination of any kind (which can be easier said than done during the house-training phase), preventing contact with high-risk individuals (e.g. young children, the elderly, anyone with a weakened immune system) and lots of handwashing on the part of everyone involved with the puppy (or kitten!).

Parvo is a very serious disease in puppies, yet people sometimes become a little complacent about vaccinating for parvo and other puppyhood diseases.   Remember, though, that the reason parvo has become so much less common than it used to be is largely because of widespread and effective vaccination.  I have to wonder about how well vaccinated Oprah's dog Solomon was to get the disease at the age he did, but there could easily be other factors involved as well.  The virus is still out there, and if we become lax in our infection control practices - including decreasing exposure of puppies to the stool of other dogs, as well as vaccination - it's waiting in the wings for its opportunity to move in. Even with the very best care the infection can still be fatal.

It's also relevant to note that, as demonstrated by Solomon's case, just because parvo is very uncommon in adult dogs doesn't mean it's impossible for them to get it.  It's important to always remain diligent.

Parvoviruses are quite species specific, so thankfully people cannot get parvovirus from dogs, but remember that puppies can get diarrhea from pathogens like Salmonella, which can be transmitted to people. There is also a human parvovirus which is the cause of Fifth disease. Just like the dog virus cannot infect people, the human virus cannot infect dogs.

Image source: http://omg.yahoo.com

• Almost all foals are exposed to R. equi as neonates, but most of them never develop signs of infection.
• Giving newborn foals hyperimmune plasma (plasma with extra antibodies against R. equi) may have some beneficial effects on farms where the infection is a recurrent problem, but this practice is still controversial.
• Adult horses are essentially immune to the infection.
• In almost all cases if clinical disease in foals, the R. equi strain involved carries a special gene called vapA.
• Mortality rates in foals vary considerably from 0% to 30%.
• So far, efforts to develop a vaccine to help protect foals have been unsuccessful, but research in this area is ongoing.

People can also be infected with R. equi, and as in foals, pyogranulomatous pneumonia (infection of the lungs which results in the formation of many abscesses) is one of the most common conditions caused by this organism. However, there are a few important differences between infection in people and infection in horses:

• 85% to 90% of people with R. equi infection are immunocompromised, meaning their immune system is weakened or suppressed for some reason, e.g. HIV infection, or immunosuppressive drugs taken by organ transplant or cancer patients.
• Among people infected with R. equi who have normal immune systems (i.e. immunocompetent), about half of the infections are localized, meaning they only affect one small part of the body. Many of these are associated with wound infections.
• Only 20% to 25% of the R. equi isolates in people carry the vapA gene.
• Infection in immunocompetent people can be fatal in approximately 11% of cases, but among HIV-infected patients the mortality rate from R. equi infection can be as high as 50% to 55%.

Rhodococcus equi is actually a soil organism, and this is likely the most common source of the organism for both horses and people. Only approximately 1/3 of humans infected with R. equi report that they have had contact with horses or pigs (pigs can also carry the bacterium). So we don't know how much of a risk an infected foal is to a person.  However, it is prudent for people, particularly those with weakened immune systems, to take precautions to avoid potential transmission of R. equi from horses.

• Try to reduce dust levels on the farm. Because R. equi most often lives in the soil, it can get stirred up into the air in dusty areas, which can then lead to inhalation by animals and people. Doing things like planting grass or other vegetation, installing windbreaks in high-traffic areas, or wetting down dusty stalls or paddocks can help reduce dust levels in the air.
• Keep open wounds and other broken skin covered when working around animals.
• Always wash your hands after handling a foal (or any horse)
• If you have a foal that develops signs of R. equi infection, make sure you have your veterinarian examine it as soon as possible so the diagnosis can be determined and the foal can be treated properly as soon as possible. Some foals with R. equi may develop severe pneumonia very quickly, so it’s important that they are examined right away.