Worms & Germs Blog

PetTickTracker Update

Posted in Cats, Dogs, Horses

Over the years, we’ve tried a variety of new approaches to promote awareness or get relevant research information. Some (like this blog) have taken on a life of their own and exceeded our expectations. Some didn’t go very far. Our most recent initiative is the PetTickTracker, a website designed to collect information about ticks found on animals. The hope is that we’ll raise awareness, see where ticks are being found, see if ticks are being reported in areas where they haven’t been in the past and identify movement of new tick species in the area. That can indicate what education campaigns might be needed or identify specific areas where targeted tick dragging might be useful to follow up on interesting results.

That was the thought, at least.

It was launched two weeks ago, and I had no idea what to expect.

So far, we’ve had >1100 submissions…way more than I thought, and great news. We’re in the process of looking at the data now, and hopefully we’ll have some mapping data to present here soon. In the interim, here are some tidbits:

  • Most reports were from dogs, accounting for 84% of submissions. That’s probably a reflection of their likelihood of exposure, their close observation by people and the number of dogs in households.
  • The black legged tick (Ixodes scapularis) was most commonly reported, accounting for the majority of identified ticks. Dermacentor variabilis, the American dog tick, was #1. “I don’t know” was #3, showing how more tick ID education and resources are needed.
  • The Lone Star tick (Amblyomma americanum) was reported 20 times in Ontario. That’s a tick type we’re watching in case it’s establishing itself in the province.
  • 70% were thought to be adult ticks. Age wasn’t certain for 22% of submission, and 8% were identified as nymphs.
  • ~17% of animals had travelled >20km in the past 2 weeks. This shows how mobile out domestic animal populations are and how it’s possible to track ticks around between regions.


Keep the submissions coming! The PetTickTracker can be accessed here (https://uoguelph.eu.qualtrics.com/jfe/form/SV_8pEFcT8xAEyK6hv) or via the QR code below.

TickTracker short QR code


Human Rabies: Virginia

Posted in Dogs, Rabies, Vaccination

scruffy-puppyEvery few weeks I get a call or an email about travel-associated rabies exposure concerns. It’s usually from someone traveling to southeast Asia or India who has been bitten by a stray dog. Most of the time, it’s an unvaccinated person and the dog isn’t available for monitoring or testing. Since rabies is endemic in dogs in those areas and there’s no way to rule it out if the dog isn’t identified, it has to be considered a possible rabies exposure and is an indication for post-exposure prophylaxis (PEP). Sometimes PEP can be done in the country being visited, but often it’s done when the person gets home. In most situations, rabies exposure is best considered a medical urgency not a medical emergency. The incubation period for rabies is pretty long, and as long as PEP is started in a reasonable period of time, rabies is virtually 100% preventable. There are some situations where very prompt treatment is indicated, such as a bad bite to the head or neck, since rabies virus can move through the nerves to the brain much quicker in such a case given the close proximity.  With most exposures, there’s usually ample time to organize things and get home for treatment, often without needing to change travel plans.

Unfortunately, lack of awareness leads to rabies deaths. That’s a big problem in developing countries where the virus is endemic and thousands die ever year, but public awareness of what to do is still poor.

It’s also an issue with travelers. People often don’t go to travel clinics before visiting these regions or if they do, they don’t want to pay the rather expensive cost of pre-exposure rabies vaccination. Most often, they get away with it. However, travel associated rabies deaths occur occasionally.

A recent example is a person from Virginia who contracted rabies from a dog bite in India. I haven’t seen many details about the case, but I expect more information will come in the form of a CDC publication in the future.

Regardless, it’s a reminder that this disease is a major concern in many parts of the world, particularly areas in Asia, India and Africa. Vaccination isn’t cheap, but it’s a highly effective preventive measure for an almost invariably fatal disease.

It’s also a reminder that travelers need to know the risks and what to do. Without vaccination, rabies is still almost completely preventable if post-exposure prophylaxis is started, even weeks after exposure.

Thinking about things that can kill you isn’t at the forefront of people’s minds when planning a trip, but a little prevention can go a long way.

Pet Tick Tracker

Posted in Cats, Dogs, Horses

PHIL 22182 IxodesIt’s pretty clear that tick ranges are changing. In Ontario, we’ve seen movement of ticks into areas where they were never seen before, as well as potential changes in the types of ticks that are found in different areas. The potential for tickborne diseases like Lyme disease highlights the importance of understanding tick distributions. Knowing where ticks are helps determine the need for tick prevention practices, and knowing the types of ticks that are present helps determine what diseases need to be considered. As some tick species establish footholds in new areas, it’s important to recognize and communicate this as early as possible.  (Image shows a female Ixodes scapularis tick laying  her clutch of eggs, CDC Public Health Image Library 22182).

Various efforts are underway to track ticks and to figure out what pathogens they carry. We’re launching a preliminary project as well, the Pet Tick Tracker. This is a simple online tool where owners and veterinarians can enter information about ticks that they find on dogs, cats, horses or other domestic animals. This is the “lite” version for now – a slightly more comprehensive version that obtains a little more location information and includes a comment box will be released when it clear the University of Guelph Research Ethics Board. Stay tuned for that, but in the interim, people finding ticks on domestic animals can access it here:


The QR code below can also be scanned directly or printed off for future reference. With a QR code reader, a smart phone will be taken directly to the Pet Tick Tracker.

TickTracker short QR code


Modified Live Vaccines: Pets and Immunocompromised Owners

Posted in Dogs, Vaccination

Lately I’ve had a run on questions from veterinarians along the lines of “I have a client who is immunocompromised and their physician has said their pet should not receive a modified live vaccine. What should we do?

  • dog-nose-closeup There are a few different types of vaccines. Modified live vaccines are vaccines comprised of (as the name suggests) bacteria or viruses that have been modified to make them less virulent. They can be highly effective vaccines, as they help the immune system learn to defend the body from the normal bacterium/virus (in the same way) without having to handle the disease itself. They’re safe for normal individuals, but in immunocompromised people, these types of vaccines are typically avoided because the body still needs to “fight” the much less dangerous but still live vaccine version of the pathogen.

But what about pet vaccines?

There’s concern that giving a pet a modified live vaccine might result in a person being exposed to the same modified bacterium or virus.

But, what is the real risk?  We don’t know. However, when you think about what the issues really are, there are clearly some things to consider.

Is the “normal” bacterium/virus a problem in people?

  • If not, then the modified version won’t be a problem either. Most of the diseases we vaccinate pets against using a modified live vaccine are not caused by bacteria or viruses that can infect people, even at “full strength”. So, those vaccines are no concern at all.
  • If yes, it’s a tougher call. The main vaccine that causes concern is intranasal or oral administration of modified live Bordetella bronchiseptica, a bacterium that is one of the component causes of “kennel cough” (or more appropriately canine infectious disease respiratory complex (CIRDC)). This bacterium causes occasional infections in people. There are also a couple of reports of infections in people with the intranasal vaccine strain, but these cases either aren’t particularly strong or involve abnormal situations (such as accidentally being squirted in the eye with the vaccine).

What’s the cost-benefit?

  • If there is a potential risk, what’s the potential benefit? Does preventing disease in the animal reduce the risk to the person, because of the potential for exposure to the normal strain from the pet if it gets infected, or from the potential of being exposed to an antibiotic resistant bacterium if the animal gets sick and needs antibiotics? That’s a tough one to figure out, but certainly warrants consideration.

Is an animal vaccinated with a modified live bacterium a higher risk animal than any other animal?

  • This often doesn’t get considered. If you show me a dog vaccinated with a modified live vaccine and ask me to list the top things with which the dog is likely to infect a person, the modified live bug won’t even crack the top 10 (or 20). So, I can’t see how a dog that has been vaccinated really increases the infectious disease risk posed by a pet.

That doesn’t mean we should ignore the issue completely, since there are some things we can probably do to drop the already low risk even more. This mainly revolves around modified live Bordetella vaccination. A few simple, practical and logical measures would be:

  • Keep the high risk person out of the room when the animal is being vaccinated, to prevent high level exposure directly to the vaccine.
  • Wipe the face of the animal after vaccination to reduce the burden of the vaccine bacterium on the outside of the animal.
  • Avoid close contact with the animal’s face for a short period of time. Realistically, if someone is immunocompromised enough that they are concerned about vaccination of their dog, close contact with the dog’s face should be avoided at the best of times.
  • Encourage hand hygiene after contact with the dog. As above, that’s a good general precaution at any time, but can be emphasized during the day or two after vaccination.

New Guidance for Human Exposure to Rabies: Ontario

Posted in Cats, Dogs, Other animals, Rabies, Vaccination

This month, Public Health Ontario released a new Rabies Guidance Document for Healthcare Providers. It’s nothing particularly new but a good review of the recommended response to rabies exposure from various animal species, something that’s unfortunately often messed up or made more complicated than necessary. It includes some nice flowcharts, such as the one below. The full document can also be accessed via the PHO website.

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Rabies in a 3 Month Old Puppy with Human Exposure

Posted in Dogs, Rabies, Vaccination

In many countries, rabies is a disease we’re concerned about but one that is rarely seen in domestic animals and is exceptionally rare in people. It’s easy to forget that people in other areas are confronted with a risk of rabies on a regular basis. Canine rabies is a major problem in Africa, leading to major challenges for veterinarians, public health personnel and the general population. Dr. Philip Mshelbwala is a veterinarian in Nigeria, with special interest on rabies research. He holds a certificate in Rabies Surveillance and Control of the University of Lausanne, Switzerland and currently works with the University of Abuja, Nigeria. Philip will be providing some front-line information about the challenges of rabies in Nigeria.

P.P. Mshelbwala: On February 23, 2017 a para-veterinarian brought a 3 month old puppy to the attention of a veterinarian in Gwagwalada, Federal Capital Territory, Abuja, Nigeria following unsuccessful empirical treatment of babesiosis. Further history from the owner revealed that 3 of his puppies were attacked 2 weeks earlier by a stray dog. One of the puppies died instantly from trauma, while the other two survived with bite wound injuries. Veterinary care was not sought until 2 weeks later, at which time unusual behaviour was observed. The para-veterinarian treated the dogs for babesiosis; however, one died during the course of treatment, which prompted him to call the attention of a private veterinarian. On presentation the puppy was recumbent, with clear spasms and muscle tremors . There was marked salivation, unusual violent biting behaviour and vocalization. The puppy was quarantined and died the following day.


The brain was removed and rabies was diagnosed by Fluorescent Antibody Test at the National Veterinary Research Institute Vom, Nigeria. A visit was then made to the house for contact tracing. Following questioning, it was determined that five people, including the para-veterinarian, private veterinarian, an owner, the owner’s security guard and a cousin, were exposed to the puppy. They were all advised to go for full post exposure prophylaxis (PEP), with each dose costing $10. Despite public education to those exposed, the security guard and para-veterinarian refused to undergo PEP.

IMG_20170304_123749An outbreak response vaccination campaign was also organized. Notices of vaccination and educational materials were prepared and distributed in all the households in a 50 km radius from the index case by team of 2 veterinarians and 10 veterinary students from the University of Abuja and VET Ville. A total of 220 dogs were immunized using house-to-house strategy. This required the support of many people, including the director Veterinary Teaching Hospital who provided a vehicle and vaccination supplies and the Federal Ministry of Agriculture and Rural Development, who provided the vaccines, as well as the people that did the investigation.

IMG_20170304_155227J.S. Weese: This report highlights the challenges of rabies. The cost and time commitments required here were major and it’s impressive that this degree of response was coordinated in such a short time. However, it’s much more cost-effective to vaccinate dogs than to do emergency response. The typical target for canine vaccination to control rabies in a region is 70%… with 70% of dogs vaccinated, eradication is possible. That’s a hard number to reach, especially in areas with large feral dog populations. While emergency response vaccination campaigns are important, more structured, large scale vaccination is needed to reach that goal. Campaigns such as Mission Rabies (something we’ll be reporting on later) are needed for both vaccination and education, with education being a critical and often overlooked aspect. Despite timely intervention, the vaccine couldn’t go around the whole community, as a case was reported in a community nearing that of the index case, three weeks after. Despite the history of dog bite, the para-veterinarian didn’t consider checking for rabies, showing knowledge gap.  There is therefore the need to organize a large scale vaccination campaign to target 70% dogs.  Also there is the need for large scale public education on rabies, both on radio and television as it is done for other diseases of public health significance. Veterinarians need to be stationed at each local government area to help in surveillance.

Rodent Importation…Booming Business, Booming Risks?

Posted in Pocket pets

HamstersThe recent (ongoing) Seoul virus outbreak associated with pet rats and recurrent Salmonella outbreaks linked to feeder rats have focused more attention on the national and international movement of rodents. Most people probably don’t realize the massive number of rodents that are shipped internationally, and we don’t really understand the risks. Anytime animals are moved from one population to another, they can bring infectious diseases with them. In general, the more movement (both in terms of occurrences and distance), the more risk.

A recent paper in the journal Transboundary Emerging Diseases (Lankau et al, Public Health Implications of Changing Rodent Importation Patterns – United States, 1999-2013) describes data about rodents (legally) imported into the US over more than a decade, acquired using a Freedom of Information Act request.

Here are some highlights:

  • 4435 rodent shipments were identified. The number of shipment increased significantly between 1999 and 2013.
  • The total number of rodents imported was 1,490,383, with a peak of 246,040 in 2007.
  • Rodents came from 68 countries, including countries from all continents except Antarctica.
  • Shipments from Africa plummeted in 2004, associated with a change in regulations that followed the rodent-associated monkeypox outbreak in people in the US.
  • Only 34 (0.8%) of shipments were denied entry. Four were abandoned (I’m not sure what happened to those), 12 were sent back and 18 were seized (I don’t imagine that ended well for the rodents).
  • 80 different species were imported, although some shipment records did not have clear species information, so it was stated that up to 100 different species might have been involved.
  • As time passed, hamsters, chinchillas, guinea pigs and gerbils became an increasing majority of the imported rodents. Presumably most of these were destined for the pet trade. Hamsters, in particular, were common, accounting for close to 85% of all imports.

Where the animals went and if they brought any problems (e.g. infectious diseases) with them cannot be tracked. It’s assumed that the bulk of imports went to the pet trade.

There are valid reasons for animal importation, and some reasons that are hard to justify. One thing to consider is whether importation is really needed, at least on this scale. It’s not exactly difficult to breed those most commonly imported species in captivity, so I have to assume that cost is a motivator. It’s simply cheaper and easier to import massive numbers of pet rodents from large scale breeding operations in certain countries. Large commercial breeding operations may pose increased risk because of the potential for widespread dissemination of infectious agents, something that has been seen with a variety of pathogens. It also raises welfare questions, with large scale breeding and long-distance shipping, versus local smaller scale breeding and shorter distance transportation. What percentage of animals born in those operations are alive in households a year later? I have not idea, but fear the number is low. Another thing to consider is behavioural issues. Bites are among the biggest problems associated with pet rodents. Is an animal bred in a warehouse in Europe and shipped to North America, passed through a large central warehouse, distributed to a local pet store then sold into a household going to be a well-adjusted pet? Maybe, maybe not. Local breeding doesn’t mean it’s guaranteed to be well-adjusted either; however, I have to assume that a small scale breeding operation and less stress of shipping would only help.

Cost drives a lot of this. So does lack of public awareness. Would people pay a premium for a locally raised hamster? Maybe, since the cost is pretty low already. Locally-sourced animals aren’t necessarily safer and they can still pose various risks (as the Seoul virus outbreak showed), but there’s probably an added degree of risk from imported animals. People simply don’t think about from where that animal in the pet store comes, and they usually don’t think about disease risks and what they need to do to reduce those risks either. More public education could go a long way.

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Petting Zoos, Outbreaks and Denial

Posted in Other animals, Parasites

baby-goatI think petting zoos can be great. I’ve taken my kids to many and think they’re a great way for people to see and interact with animals they would not normally encounter.

However, there’s always some risk, and petting zoos range from exceptionally well run to horrible. It seems like there’s been steady improvement over the past 10 years or so in how petting zoos are managed, but problems persist. Some risks are the inevitable consequences of contact with animals. However, in most, if not all, there are obvious things that could be done to reduce the risk to people. Unfortunately, young kids bear the brunt of petting zoo infections, and serious disease can occur.

It’s early for the start of petting zoo outbreak season, but an animal rescue farm in Pennsylvania has been closed for investigation of a cryptosporidiosis outbreak.

Cryptosporidiosis is caused by the microscopic parasite Cryptosporidium, which is commonly found in some animals, particularly young calves, kids (as in baby goats) and lambs. It can cause nasty, although usually short-lived intestinal disease in people, but severe disease is possible in the very young, very old and people with compromised immune systems. One problem with “crypto” is that it’s hard to kill. The parasite is resistant to most disinfectants and alcohol-based hand sanitizers, so when someone gets it on their hands after contact with manure or manure-contaminated surface, thorough hand washing is needed. Unfortunately we know that’s something that doesn’t get done well enough at petting zoos, for various reasons. It’s also why avoiding contact with calves and other young ruminants is a standard (and often ignored) petting zoo guideline recommendation.

The recent outbreak at Heaven On Earth in Bethlehem Township, PA, involves at least 5 confirmed cases. Hundreds of people were potentially exposed so presumably there are other currently unidentified cases.

A crypto outbreak investigation is usually going to focus on a few key things, such as:

  • Was there contact with high risk species such as calves?
  • Were adequate handwashing stations present?
  • Was there adequate signage to encourage handwashing?
  • Were people eating and drinking in the petting area?

The farm recently took in 30 kid goats and had asked for volunteers to help hand feed them. That’s a group of high risk animals and potentially a group of high risk people (if they don’t have any training on how to avoid crypto). It appears that young kids were involved in this, and the Facebook page for the facility has a post from the parent of a 3-year-old that had helped feed the kids and got crypto.

It’s reported that the farm is now closed to the public, which is a sensible response during a outbreak (although their Facebook page has comments from people who visited yesterday, so it’s not clear to me what’s happening). There seems to be the typical level of denial, as reported by local media: [“The farm owner] said he is working with the Health Department to determine the origin of the reported sicknesses. He said he isn’t sure anyone was infected at the farm, but it is possible. “People come every day with their kids and we never had a problem,” Melhem said. “I’m fine.  I’m here every day.  Three or four women are here every day and none of them are sick.”

It’s never happened here before (that they know of) and I’ve worked here for years and have never had a problem are typical refrains, but it’s pretty much guaranteed the farm was the source.  Their Facebook page shows evidence of even more denial.

Outbreaks aren’t always someone’s fault, but there’s almost always something that can be done to improve and decrease the risk of the same thing happening again. Given the lack of understanding or acceptance, let’s hope this place stays closed to the public and focuses on their rescuing, not public visitation.

Colistin Resistance in Pets

Posted in Cats, Dogs

DNA helix2I’ve had a lot of emails over the past few months from colleagues from other countries, asking if we’re finding much mcr-1 in Canada. mcr-1 is a gene that makes bacteria resistant to colistin, a “drug of last resort” in people with some highly resistant infections.  The gene has emerged in bacteria from both animals and humans. It’s also been found a few times in a couple of different types of bacteria from food animals and food products in Canada.

This gene probably originated in food animals and is likely distributed in farm animals internationally, although only recently have researchers starting testing for it. I’ve been interested in the pet side, particularly following a report last year of mcr-1 in multiple dogs and cats in a Chinese pet store (after infection of a pet store employee was identified). When there was a large shipment of rescue dogs from China to Canada late last year, I would have loved to have tested some of the animals for mcr-1 in the bacteria they were shedding, along with various other things (for example, we know that multiple cases of distemper were associated with that particular group of dogs).

A recent paper in Emerging Infectious Diseases entitled mcr-1in Enterobacteriaceae from companion animals, Beijing, China, 2012-2016 highlights these concerns.

In that study (Lei et al, 2017) they tested Enterobacteriaceae from healthy and sick dogs and cats from Beijing’s Veterinary Teaching Hospital of the China Agricultural University. Enterobacteriaceae is a group of Gram negative bacteria, including most notably E. coli, Enterobacter, Salmonella and Klebsiella. The results were a bit scary:

  • 14% of the 566 isolates tested were resistant to colistin. This was mainly in E coli and Klebsiella.
  • 62% of the colistin-resistant isolates harboured mcr-1.
  • Bacteria that possessed mcr-1 were typically resistant to many other antibiotics, but were susceptible to some drugs.
  • Many different strains were involved, showing that this gene has moved to lots of different bacteria that have dispersed in the population.
  • 7/35 pet food samples (primarily chicken-based) were positive for mcr-1. What this means is unclear. Testing was done by PCR, which detects DNA, not necessarily live bacteria. So the bacteria containing mcr-1 could have been killed in cooking. But wow – that’s a concern, and further suggests that this gene may be highly prevalent in food animals.

Why was the colistin resistance rate so high? That’s an interesting question, since colistin is not used to treat dogs and cats (as opposed to food animals in some regions). It could reflect widespread exposure from food and the environment. It could also reflect use of other antibiotics in pets, since use of any drug to which the bacterium is resistant can select for that bug, and all its genes (e.g. if a bacterium is resistant to ampicillin and colistin, use of either drug will select for it).

What’s the threat to pets? Pretty minimal, since we don’t use colistin in pets.

What’s the threat to people? That’s the big question, since sharing of mcr-1 ­containing bacteria can definitely occur. The main concern is that pets might be a reservoir of mcr-1-carrying bacteria in households and the community. More work needs to be done to assess this risk, and look at mcr-1 in various species in other countries.

Immunocompromised People and Their Pets

Posted in Birds, Cats, Dogs, Other animals, Pocket pets, Reptiles

Cat on bed2This month’s edition of the Internal Medicine Journal contains an article entitled High rates of potentially infectious exposures between immunocompromised patients and their companion animals: an unmet need for education (Gurry et al. 2017). The study is fairly superficial and there’s nothing particularly surprising in the paper, with results similar to what has been reported in the past (including one of our earlier studies on high risk children (Stull et al. 2014)). The sad part, perhaps, is the conclusion that there is a need for increased education of patients – something that’s been said many times before but with little resulting action.

Here are some highlights from the study, which surveyed 265 adults with a few types of disorders that would increase their risk of infection.

  • 52% owned an animal. That’s pretty consistent with other studies and what we know about pet ownership in general. High risk people tend to have the same ownership patterns as the general public.
  • Dogs and cats were the most common pets, but other species were also reported. 3% owned reptiles, which are  very high risk pets for immunocompromised individuals.
  • 30% of individuals reported having been bitten or scratched by their animal at some point. This probably poses the greatest risk for most pet owners (beyond reptile owners, where Salmonella is the main concern).
  • Close to half allowed their pet to sleep on/in the bed. That’s gotten a lot of attention in the past and I really don’t get too concerned about it in most situations. (On the bed is also different than in the bed, or sleeping right against your face.)
  • Only 17% recalled getting some information from healthcare workers about safe practices around their pets. If anything, that’s probably higher than average, showing a major gap that needs to be filled.

I think most people would agree that we need better education for high risk people about pets and zoonoses. How to actually get that done is the challenge.