Maureen Anderson
Maureen Anderson is currently a post-doctoral fellow in the Department of Pathobiology at the University of Guelph. She grew up in Montreal, Quebec. In 1998 she moved to Guelph, Ontario where she completed her veterinary degree in 2003. Following a year and a half in mixed animal private practice in Listowel, Ontario, she returned to the University of Guelph for graduate studies in infectious disease and a residency in Large Animal Internal Medicine. She completed her thesis on methicillin-resistant Staphylococcus aureus (MRSA) in horses in December 2007, and became board certified with the American College of Veterinary Internal Medicine (ACVIM) in the spring of 2008. She has two cats named Bonnie and Clyde.
Newborn killed by Husky
Another tragic dog bite incident has resulted in the death of a three-week-old baby in Quebec. The baby's mother (17) and grandmother (37) left the child alone in the house, strapped to her car seat on a chair, while they went outside for a smoke. There were also two Huskies loose in the house at the time. Although the women were only a few meters from the open door, and came back inside when they heard noise, by the time they reached the baby it was already too late. The paramedics found the baby "covered in deep bite marks and scratched.
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
Ringworm at the OSPCA
Never a dull moment...
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
World Hand Hygiene Day
Today is World Hand Hygiene Day, an occasion being promoted by the World Health Organization’s (WHO) “SAVE LIVES: Clean Your Hands” campaign. This WHO initiative is aimed primarily at improving hand hygiene in healthcare facilities around the world, in order to help reduce healthcare-associated infections (HAIs) (e.g. infections that people develop while in hospital). Also to mark World Hand Hygiene Day, the CDC has launched its new hand hygiene website, which has tons of information on hand hygiene basics, guidelines, resources for promotional campaigns, and information for patients.
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.
Risks of Raw - More evidence
A study by Erin Leonard of the University of Guelph and others, that has just been published in the journal Zoonoses and Public Health, once again points to the increased risk of Salmonella shedding associated with feeding raw diets to dogs. The study looked at 138 dogs from 84 households in Ontario. One-quarter of households (21/84, 25%) had at least one dog (32/138, 23.2%) that was shedding Salmonella at one time, which is considerably higher than the 1-4% of pet dogs that are typically expected to be shedding this zoonotic pathogen. Only 4 of the 32 positive dogs had any history of diarrhea in the last month, so the vast majority of these dogs had no signs that they were shedding Salmonella. Here were the study's main findings:
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.
Baylisascaris in Winnipeg
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There was another paper published in the August issue of the Canadian Veterinary Journal about Baylisascaris procyonis (roundworms) in raccoons, this time in Winnipeg, Manitoba (Sexsmith et al 2009). The study was actually undertaken after infection with B. procyonis larvae was identifed as the cause of death of several animals in the collection at the Assiniboine Park Zoo in Winnipeg.
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.
Things not to do for Thanksgiving
I heard this on the radio yesterday morning, I kid you not: Butterball has a "Turkey Talk" toll-free helpline, which naturally gets busy around turkey holidays like Thanksgiving and Christmas. Like many helplines, they get stories of every kind, and this year apparently one person called in and asked if it was alright that she thawed her frozen turkey in the bathtub - while her kids were in it taking a bath!
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!
Antibiotic Awareness Day
European Antibiotic Awareness Day is an initiative of the European Centre for Disease Prevention and Control. This year it falls on November 18. The aim of the Day is to provide an annual opportunity for raising awareness about the threat to public health of antibiotic resistance and how to use antibiotics responsibly.
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.
Swine flu has gone to the birds
Just when all those turkeys that managed to survive Thanksgiving weekend thought their troubles were over, there's new issue: H1N1 influenza (formerly known as swine flu) has been found in an Ontario turkey flock. The H1N1 virus was first reported in birds in Chile in late August.
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!
Canine lepto: It's that time of year again
The latest newsletter from the University of Guelph's Animal Health Laboratory contains a brief update on the percentage of positive MAT tests for canine leptospirosis that the lab has seen in the first half of 2009. Approximately 30% of the tests have been positive, which is up from the previous two years. However, the prime time for lepto cases (and therefore typically also lepto testing) is just starting: the cool damp fall weather provides a great environment for lepto bacteria to survive outdoors for the next several weeks.
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))
Cooperating on Q Fever
Another surge in the number of cases of Q fever in people in the Netherlands has been reported. Prior to 2007, the average number of cases of Q fever per year in the country was only 15. In 2007 there were 192 cases, and last year there were 958 cases, making this the largest community outbreak of Q fever ever reported. At the beginning of May 2009, another jump in the number of cases - over 200 - was reported by the dutch newspaper de Volkskrant.
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.
