The latest version of A Guide to Mitigating the Risk of Infection in Veterinary Practices During the COVID-19 Pandemic (15-Jun-2021) has been released.  It can also be accessed through the Ontario Veterinary Medical Association Coronavirus FAQ webpage (member login required).

The main changes are a new section summarizing various considerations for re-opening of veterinary practices to clients, and minor updates to other areas such as ventilation.

Previous versions of the guidance and other related documents can be found on the Worms & Germs COVID-19 Veterinary Resources page.

I get asked about this topic a lot. Early in the pandemic, I wrote a post about options for caring for pets of people with COVID-19.  Some things have changed a bit now that we know more know about SARS-CoV-2 in animals and the associated zoonotic risks, and we have a vaccine for people.

One example of a commonly encountered scenario is: A dog owner is being hospitalized because of COVID-19 and a friend or family member has been asked to take care of the pet.

What are the risks to the caretaker of the dog?

  • We don’t know. I’d consider it very low but I can’t say it’s zero.
  • Person-to-dog transmission of SARS-CoV-2 is fairly common in households where the owner has COVID-19, based on our and other groups’ surveillance efforts. However, dogs are not really a great host for this virus and infections are probably fairly low grade and transient, and therefore low risk for further transmission.
  • Dog-to-dog transmission of SARS-CoV-2 hasn’t been seen experimentally, but the studies to date have been fairly small so we can’t read too much into that.  Nonetheless, it’s clear that dogs are lower risk than cats for passing the virus on to other individuals. Yet, live virus has been grown from canine respiratory secretions, suggesting there is at least some plausible risk.

What can or should be done in this situation?  There are two key considerations:

1. Should the person in question agree to look after the animal at all?

  • This requires consideration of the risk status of everyone in the household (e.g.  is anyone at high risk of serious disease if they get infected?), vaccination status of everyone in the household, whether other pets are present, how well the dog can be contained in the household, and whether the household members are willing to accept a small degree of risk.
  • The best case scenario is to send the dog to a pet-free household where everyone is vaccinated and where they can keep the dog away from other people or animals (e.g. they have a fenced yard). Asking someone else to look after a pet like this was harder earlier in the pandemic, but now that we have highly effective vaccines, it’s easier.  Asking if someone from a fully vaccinated household will take the job is reasonable.

2. How should the dog be managed?

  • That also depends on the risk status of the household. In a vaccinated household, I’d say it can be “business as usual” in the house, but restricted outside. By that, I mean I’d do nothing different with the human-dog interactions in the household, but when the dog goes outside it should be under control (e.g. on a leash, or in a fenced yard) so the dog doesn’t interact with other people or dogs from outside the household.
  • If there are unvaccinated people in the household, it’s tougher. I still consider the risk of transmission from a dog to be very low, but I can’t say it’s zero. So, it would be prudent to keep the dog away from unvaccinated individuals as much as possible for the first 14 days (7 days is probably reasonable if it’s a major issue, but 14 days is ideal).  That doesn’t mean locking the dog in the bathroom and never going near it, but rather avoiding contact with respiratory secretions, not having the dog in the same small airspace for prolonged periods of time (e.g. not sleeping in the bedroom), and focusing on good hand hygiene.

The main issue is we just don’t know the risk. It’s definitely very low and could be zero, but I don’t think we can say it’s zero at this point. Vaccines are a game changer for these scenarios.

Okay, but what if the pet in question is a cat instead of a dog?

That changes the risk a bit, but not really the overall approach. Cats are more susceptible to SARS-CoV-2 and cat-to-cat transmission can occur, so there’s also more concern about the potential for cat-to-human transmission.  That means the issues above all apply to cats as well, but are probably heightened.

My focus here would be on finding a vaccinated household to look after the cat, if possible.  If not, it’s a matter of restricting contact with anyone who isn’t vaccinated. The good thing about cats is they are (for the most part) easier to contain than dogs.  They can be kept in a large cage or kennel if necessary, or they can be confined more easily to certain areas of the house, and cats don’t need to go outside. So, if someone who’s unvaccinated has to take in a cat, it’s easier to limit contact. The concepts above still apply, with a goal of minimizing the closeness and duration of contact during the first 7-14 days after the cat is removed from the person who was infected with COVID-19.

We’ve seen some increased awareness of the risks associated with dog importation, and countries taking measures to reduce disease and welfare problems, including here in Canada and more recently potential future measures in the UK.

The US just raised the bar a huge amount with new restrictions on importation of dogs from over 100 countries considered high-risk for canine rabies, which were announced today.  Starting July 14, 2021, dogs from those countries will not be allowed into the US, except for those with advanced approval on “an extremely limited basis.” Dogs from those countries that show up at the US border without pre-approval will be returned to their country of origin at the importer’s expense.

This is a logical move to try to curtail high risk activities that could potentially result in the importation of rabid dogs. It will interfere with some legitimate rescues, but more importantly it will impact massive puppy mill exporters and puppy brokers. Whether that will just drive those dogs to other countries (e.g. Canada… we import huge numbers of dogs from countries on this list) is unclear.  It will be interesting to see if other countries follow suit with similar restrictions.

The full list of countries considered high-risk for rabies is below:

Africa

  • Algeria, Angola
  • Benin, Botswana, Burkina Faso, Burundi
  • Cameroon, Central African Republic, Chad, Comoros, Côte D’Ivoire (Ivory Coast)
  • Democratic Republic of the Congo, Djibouti
  • Egypt (Temporary importation suspension of dogs from Egypt until further notice)
  • Equatorial Guinea, Eritrea, Eswatini (Swaziland), Ethiopia
  • Gabon, Gambia, Ghana, Guinea, Guinea-Bissau
  • Kenya
  • Lesotho, Liberia, Libya
  • Madagascar, Malawi, Mali, Mauritania, Morocco, Mozambique
  • Namibia, Niger, Nigeria
  • Republic of the Congo, Rwanda
  • Sao Tome and Principe, Senegal, Sierra Leone, Somalia, South Africa, South Sudan, Sudan
  • Tanzania (including Zanzibar), Togo, Tunisia
  • Uganda
  • Western Sahara
  • Zambia, Zimbabwe

Americas & Caribbean

  • Belize, Bolivia, Brazil
  • Colombia, Cuba
  • Dominican Republic
  • Ecuador, El Salvador
  • Guatemala, Guyana
  • Haiti, Honduras
  • Nicaragua
  • Peru
  • Suriname
  • Venezuela

Asia and the Middle East, Eastern Europe

  • Afghanistan, Armenia, Azerbaijan
  • Bangladesh, Belarus, Bhutan, Brunei
  • Cambodia, China (excluding Hong Kong and Taiwan)
  • Georgia
  • India, Indonesia, Iran, Iraq
  • Jordan
  • Kazakhstan, Kuwait, Kyrgyzstan
  • Laos, Lebanon
  • Malaysia, Moldova, Mongolia, Myanmar (Burma)
  • Nepal, North Korea
  • Oman
  • Pakistan, Philippines
  • Qatar
  • Russia
  • Saudi Arabia, Sri Lanka, Syria
  • Tajikistan, Thailand, Timor-Leste (East Timor), Turkey, Turkmenistan
  • Ukraine, United Arab Emirates, Uzbekistan
  • Vietnam
  • Yemen

I get calls about concerns regarding increased respiratory disease in dogs all the time.

  • Sometimes, they’re the result of local disease outbreaks.
  • Sometimes, they’re just a result of increased awareness of the normal “baseline” disease rate, since “kennel cough” is always occurring at some level.
  • Sometimes, the circumstances just seem different, and we need to get more information.

The last of these is where I stand at the moment. I’ve been getting more reports of canine infectious respiratory disease, including a concerning number of reports of severely affected dogs (with some fatalities). My impression is that something unusual is happening. Most often, the cause is actually one of our “usual suspects,” – the bacteria and viruses that normally cause canine infectious respiratory disease complex (CIRDC). It’s often very difficult to sort these things out because limited testing is done, there are limitations on the testing that is done, and there’s no formal tracking system for these infections.

However, we want to figure out what’s going on if we can, because sometimes we do see new (or new-to-us) pathogens (like when canine influenza hit Ontario in 2018), or we can identify hot spots for disease transmission (we’ve implicated specific dog parks in the past).

So, once again, we’re trying to track respiratory disease cases in dogs in Ontario (and beyond Ontario, if people want to report them). We have a quick online survey to collect more information and hopefully figure out if something unusual is happening and what it might be.  The survey can be accessed here: https://uoguelph.eu.qualtrics.com/jfe/form/SV_eP6E6AzIiJfnDlY

We have a lot of different concerns about SARS-CoV-2 on mink farms. Mink are really susceptible to this virus, and human-to-mink transmission isn’t uncommon, so if we continue to farm mink, we will continue to expose mink to SARS-CoV-2 as long as the virus is still circulating in people.

Two of the biggest concerns relate to the potential for infection of mink to make things worse in the “big picture:”

  1. Development of mutations of the virus in mink that lead to new variants of concern (VOCs) that spread back to people
  2. Spread of the virus to other animal species

For this post, I’ll focus on concern #2.

We want to keep COVID-19 a human-only disease as much as possible. If it gets established in animal populations, especially wildlife, that changes the game in terms of disease control. I doubt we’re going to eradicate this virus entirely regardless, but if it establishes animal reservoirs, there’s no chance whatsoever.

Furthermore, if SARS-CoV-2 gets established in animals (of any species), we may have to deal with greater risk of VOCs. VOCs are already worsening and dragging out this pandemic, and with more transmission (in animals or people), there will be more VOCs. Mutations are a normal event when viruses replicate. The more a virus spreads, the more mutations occur, and the greater the chance that a mutation that impacts transmissibility, virulence or vaccine evasion emerges.

For a virus to establish an animal reservoir that poses a risk to people, a few things need to happen:

  • Animals have to be exposed, directly or indirectly, to infected people.
  • The animal species has to be susceptible to the virus, and able to transmit it between individuals.
  • The species must live in large enough groups for sustained transmission within the population.
  • There has to be a mechanism to spread the virus back to people from the animals

That might seem like a tough list to fulfill, but it’s not impossible (and it’s what has happened with some other zoonotic viruses).

Therefore, we want to keep this virus away from animals, particularly wildlife.  This is where we come back to mink.

A recent paper in Transboundary and Emerging Diseases (van Aart et al. 2021) reports on surveillance for SARS-CoV-2 in dogs and cats on mink farms in the Netherlands, where SARS-CoV-2 was identified in over half of the mink farms in the country.

  • 13 farm dogs and 101 (mostly feral) cats (69 adults and 32 kittens) on 10 farms were tested.
  • SARS-CoV-2 was detected by PCR in 3 (4.4%) adult cats and 1 (7.7%) dog.
  • Since PCR testing just tells you a single point-in-time result, antibody testing was used to identify prior infection. Antibodies to the virus were found in 18% of adult cats, 0% of kittens and 2 (15%) dogs.
  • When PCR and serological test results are combined, 19.4% of adult cats and 15% of dogs had evidence of infection with SARS-CoV-2.

That’s pretty impressive.  There’s no guarantee that all the dogs and cats were exposed to the virus by mink vs an infected farm worker, but mink-to-cat transmission seems reasonable since these were mostly feral cats that would not have interacted closely with people. The source of infection of in the dogs is harder to tease out since they presumably had closer contact with farm personnel.

Interestingly, none of the nine domestic cats that were tested were positive, despite having infected owners. Infection was only found in the feral cats. Whether all the cats were infected by the mink or there was some subsequent cat-to-cat transmission (a likely scenario) is also impossible to discern.

Mink-to-cat infection would have been through indirect exposure, because the cats generally wouldn’t have direct contact with the mink in their cages.  This raises concerns that other species could have been similarly infected through indirect contact with the mink, including small mammals like mice, or from direct/indirect contact with an infected cat (e.g. mouse surviving an encounter with an infected cat).

These concerns are why there is wildlife surveillance conducted around many infected mink farms. That type of work has also found SARS-CoV-2 in “wild” (or more likely “previously escaped” free-ranging) mink.

What’s the relevance of all this?  It’s hard to say.

However, it supports plausible concerns about animal-to-animal transmission of SARS-CoV-2 and the need to reduce exposure to animals.  Vaccination of mink is a consideration, and I’ve written about that recently. Ultimately, the best way to reduce the risks associated with the virus in animals is to control this disease in people.

Overall, this shows the importance of the “One Health” approach and a need to be proactive to identify and hopefully prevent problems, rather than our typical reactionary approach whereby we wait for definitive proof of an animal-related issue before putting any real effort into addressing the risk.

As we start seeing a light at the end of the (long) tunnel, we have to think about how and when to restart various activities. One particular activity that I get a lot of emails about is pet therapy/visitation programs. These are great programs, where animals (usually, and ideally, dogs) are taken into facilities to interact with residents or patients. They’re not for everyone, but have been shown to have physical and mental health benefits.  Not surprisingly, they were largely stopped during COVID-19 pandemic, but many are now gearing up again.

What’s the risk of animal visitation programs?

People.

The main issue isn’t the animals (at least when it comes to dogs), it’s the human component. Human visitors pose much more risk than most pets, since people are more likely to be infected with the SARS-CoV-2 virus and an infected person poses a greater risk of spreading the virus than an infected pet. That’s particularly true with dogs, who are not uncommonly infected by their owners but who are low (or maybe almost no) risk for transmitting it back to people.  Also, if the animal happens to be infected, it’s quite possible the owner is too.

So, there is some risk from these programs, but the main (if not exclusive) risk is from an infected handler.

When can these programs restart?

The focus should really be on deciding:

  • when COVID-19 is controlled enough in humans the area
  • when resident/patient vaccination rates are high enough
  • when animal handler vaccination rates are high enough
  • what basic practices to identify high risk handlers (e.g. those with respiratory disease) need to be in place.

Should vaccination be mandatory for pet therapy program participants?

(Bracing for the next wave of anti-vaxxer “love” letters as I say this…)

In my opinion, yes, vaccination should be mandatory for the people (not the animals).  A reasonable exemption for people that TRULY CANNOT be vaccinated is reasonable, but the bar has to be high so that “cannot” and “don’t wanna” are differentiated.

Mandating vaccination of handlers would be a logical measure for a voluntary activity that involves close contact with a disproportionate percentage of high-risk participants.  Also, there’s a need to make sure handlers received both doses of vaccine, as concerns about the delta variant increase.

The other approach could be to have a phased re-introduction, e.g. fully (2-dose) vaccinated people can start first, with follow up assessment of when people who are not vaccinated can start as well. That way the policy isn’t saying unvaccinated people can’t participate, it just says they can’t yet. That’s not an unusual approach now as people start to think about re-opening in other areas and how vaccination comes into play for that.

How to we reduce the risk in the event an infected person (or animal) ends up visiting?

Good ol’ infection control and common sense. There are very good guidelines for healthcare visitation programs that apply to most animal visitation settings, and those are the core of risk reduction.  A little basic hygiene and common sense go a long way.

I’ve written before about animal vaccines against SARS-CoV-2 with regard to mink, but with Russia having recently licensed its Carnivac-Cov vaccine for use in several species (namely dogs, cats, foxes and mink) and Zoetis developing a vaccine in the US for mink, there’s continued interest in the subject, so I’ll revisit it.

I’m glad companies are working on SARS-CoV-2 vaccines for animals. It’s good to be prepared and have the work done in case it’s needed in a particular situation. Whether there’s much use for these vaccines in most animals at this time is hard to say.

When I think about SARS-CoV-2 vaccines for animals, there are three main reasons we would use them:

1. Prevention of severe disease

This is the main goal of most vaccines. However, dogs and cats don’t seem to get very sick, very often, from this virus.

  • I’m still on the fence as to whether this virus really causes significant disease in dogs at all. We have some data that suggests infection is associated with risk of very mild disease but overall, it’s still not entirely clear. However, it is clear that they rarely, if ever, get seriously ill.
  • Cats are commonly infected with SARS-CoV-2, but even cats rarely develop severe illness. There’s evidence that they can, so we can’t dismiss it. However, our research and others suggests that a large percentage of cats from households where people have COVID-19 get infected. So, we have probably had millions of infected cats worldwide since the start of the pandemic. If this was causing severe disease in a reasonable percentage of cats, I think we’d have clear signs of that by now. Since serious illness can occur in a small minority of cases, vaccination could help, but in the grand scheme of things, given the low risk of severe disease, it’s hard to say that the potential benefits justify the cost and potential adverse events.  (We don’t know about any specific adverse effects of vaccination in animals to date. I’m not talking about VITT or the misinformation about mRNA vaccine adverse events in humans. I’m talking about the typical adverse events that we can see in animals with any vaccine.) I’d rather focus on better rabies vaccine coverage and other good preventive medicine things than trying to get cats vaccinated against SARS-CoV-2. I’m not opposed to it. I just think the value is probably limited.
  • Mink are different. They are clearly susceptible to infection and it can cause serious illness and even death. The two points below probably are more important when considering vaccination of mink, but there could be mink health benefits from vaccination.

I’d be most interested in vaccination of endangered species with suspected high susceptibility that have human contact, particularly wild felids (e.g. lions, tigers) and non-human primates (e.g. great apes). Vaccination of captive animals (zoos), animals in rehab facilities and animals in areas where there’s close contact with human populations (mainly applicable to primates) might be worthwhile because of the potential implications of infection in endangered populations.

2. Prevention of transmission from animals to people

Dogs pose little risk to people, if any, in terms of transmission of SARS-CoV-2. Dog-to-dog transmission has not been seen experimentally, and infected dogs seem to have pretty low viral loads, so I doubt there’s much risk. Cats pose more risk to people. Cat-to-cat transmission does happen, so we have to assume cat-to-human transmission can occur too.  But human-to-cat transmission is still far more common. Because most infected cats probably catch the virus from their owners in the first place, they are probably “dead-end” hosts in households and rarely play a role in transmission. Cats get infected from family members, who have also infected each other, and everyone burns off the virus together. I think the greatest risk of cat-to-human transmission is when infected cats leave the house, particularly to go to a veterinary clinic or shelter. However, the risk associated with that can be significantly reduced using basic infection control practices..

The risk of animal-to-human transmission is probably highest with mink, as mink-to-human transmission clearly occurs. Vaccination of mink could be an important way to control mink-to-human transmission (but preventing human-to-mink transmission is most important).

3. Prevention of viral mutation

This is an important aspect for species that might serve as reservoirs and source of new variants. Virus variants emerge because of random mutations in the viral genome, and mutations happen when the virus replicates. So, the more the virus replicates and the more individuals are infected, the greater chance of a “bad” mutation occurring. For dogs and cats, this isn’t really a big concern. We don’t have massive numbers of dogs or cats together where widespread sustained transmission  is of great concern. Yes, a mutation could happen within a single infected dog or cat, but it’s really unlikely (and even then, it’s only relevant if that dog/cat then can pass it on to a person.)

The greatest risk of significant viral mutation in any animal species to date appears to be in mink.  We know that the virus can mutate in mink populations AND spread back to people. When you house thousands of a highly susceptible animals close together and introduce the virus from an infected person, that’s the recipe for widespread transmission and massive viral replication that’s needed for “bad”mutations to result in the emergence of a significant variant. Vaccination of mink farm workers helps reduce the risk of mink getting infected and from passing the virus back to people, but there’s still some degree of risk.

 

Overall, I can’t see a need at this point for vaccination of dogs and cats against SARS-CoV-2. The cost-benefit comparison of vaccination of those species doesn’t seem convincing.  Vaccination of high-risk (e.g. endangered) susceptible animals like large cats and non-human primates might make more sense, such as in zoos, rehab facilities and other places where there’s some degree of human contact with these species.

Mink are a different story. If we’re going to continue to farm mink, vaccination is a reasonable consideration.

The final disclaimer here is that all this is based on what we know about current virus variants. New variants always have the potential to reset our knowledge to some degree.  Variants that can infect a wider range of animal species, cause more serious disease in animals or be more transmissible from animals to humans might impact the current risks and make vaccination of other species more beneficial.  That’s why I’m glad we have some information about vaccines for animals now. I don’t think we need them currently for most species, but it’s good to be prepared should things change.

I seriously considered this as my email auto-reply today:

  • Thanks for your email. Yes, I’m aware of that new canine/human coronavirus paper that was released today. I’m in a symposium all day and have only skimmed the paper. I’ll read it later tonight and presumably blog about it.
  • PS: This isn’t the next COVID-19. Relax.

I actually got a chance to carefully read the paper, published in Clinical Infectious Diseases (Vlasova et al. 2021), and here are some of my thoughts, as promised…

The paper describes an interesting preliminary study that found a new coronavirus in a small number of hospitalized patients with pneumonia in Malaysia.  Analysis of the viral genetics was consistent with it having originated from a canine coronavirus.

To back it up a bit, there are lots of coronaviruses out there in lots of different species that we deal with all the time. Animals are likely the origin of most or all of our coronaviruses, ranging from SARS-CoV-2 to the coronaviruses that cause the common cold. Some of these jumped to people very recently. Some probably hundreds of years ago.

A few different coronaviruses are known to infect dogs. The one I pay the most attention to clinically is canine respiratory coronavirus, a betacoronavirus that’s increasingly recognized as an important cause of respiratory disease in dogs.  That’s NOT the virus they’re talking about in this study.  The dog virus the authors discuss in this study is an alphacoronavirus called canine coronavirus (CCoV), of which there are a couple types.

Back to the study:

  • In swabs from 301 people hospitalized with pneumonia, they found PCR evidence of CCoV in 8 patients.  A live coronavirus was cultured from one of those samples.
  • When they looked at the genetic makeup of the virus, it was most closely related to CCoV and therefore named CCoV-HuPn-2018 (canine coronavirus-human pneumonia-isolated in 2018).
  • It’s a new strain within the Alphacoronavirus 1 species. It is suspected to have evolved as a result of multiple different recombination events (viruses swapping RNA) between different Alphacoronavirus 1 strains.
  • Some genetic changes might have increased its affinity for people compared to regular CCoV. How well it can infect people and whether people can transmit it (to other people or dogs) isn’t clear.

Is this surprising?

Yes and no. A new recombinant virus is always noteworthy, but this is what viruses do, and why we always have to pay attention to zoonotic disease risks.

Is it concerning?

Not really. It’s not clear that the virus actually caused disease. Other respiratory viruses were found in 7 of the 8 positive patients, including the person from whom the virus was cultured. That person also had influenza. So, it’s hard to say if the virus was just there doing nothing, if it’s a rare cause of disease, if it’s an established but previously undetected cause of human infections, or something else.

Also, there was no evidence of human-to-human transmission. It’s impossible to say whether that was occurring –  presumably it was (versus repeated spillover events into multiple individuals from animals harbouring this virus) but who knows. The key is there wasn’t a concerning disease pattern.

One more thing: the study was based on samples from 2017-2018. Clearly nothing big has happened in the interim.(Well, you know what I mean. Nothing big with this virus.)

Take home message

New coronaviruses are a concern. We will see more viruses emerging that can jump from animals to people, some with pandemic potential. There are so many coronaviruses, and our interactions with nature (and the stress we’re putting Mother Nature under) mean the risk of inter-species transmission events will only increase. The more coronaviruses that we’re exposed to, the greater chance we encounter one that we’re susceptible to.  The more coronaviruses that can infect us,  the greater the chance they can recombine further to become more infectious to people.

However, this isn’t one I’m worried about. It’s worth studying more to make sure it’s not an issue and better understand the situation, but I won’t lose sleep over it.

This is best taken as another reminder that zoonotic threats are always lurking. We need to be prepared, be vigilant, have good surveillance systems and ensure we communicate – and treat our planet and its inhabitants with a little more respect.

I’ve written a lot about raw pet food in the past. Initially, the concerns were about Salmonella, since raw-fed dogs and cats have high rates of shedding Salmonella, and both pets and owners can get sick from it (owners can be infected directly by the pet or from handling or cross-contamination from the pet food… it’s always hard to sort that out).

More recently, I’ve been concerned about multidrug-resistant E. coli and related bacteria in raw pet diets. I think this may now be a much bigger but insidious risk. Eating a raw diet has been shown in a few studies to be a major risk factor for fecal shedding of highly antibiotic-resistant bacteria in pets, particularly extended spectrum beta-lactamase (ESBL) producing bugs.

There are other facets to this problem as well. A recent paper in the journal Epidemiology and Infection (Kaindama et al, 2021) describes a cluster of human E. coli O157 infections in the UK that were linked to raw pet food. This strain of E. coli can cause serious illness in people, including hemolytic uremic syndrome, which can be fatal. The bacterium can be found in the intestines of food animals (mainly cattle) and can therefore sometimes contaminate meat, or vegetables fertilized with manure.

In this cluster, 4 people infected by a similar strain of E. coli O157 were identified.

  • All 4 patients got sick within a one-month period in 2017.
  • I’m guessing three were 6-year-old children, based on the median and age range provided in the paper. The burden of zoonotic diseases often falls disproportionately on kids.
  • Three of the patients were hospitalized, and one died.

During the investigation, no typical sources of E. coli O157 exposure were identified. The only commonalities between cases were all had contact with dogs, and a history of consuming raw carrots. Three of the patients had been exposed to dogs fed a raw meat diet, two of which had received tripe from the same supplier. The other person’s dog was not fed a raw meat diet but had contact with another dog that was fed raw meat.

E. coli O157 was subsequently found in raw pet food samples from the affected households, but they were different strains. That’s not too surprising, since contamination of the pet food would be variable, and testing would have occurred well after the food that likely caused the infection was fed. One batch might be contaminated, the next not and the next contaminated with a different strain. Finding different strains doesn’t round out the story as nicely, but it highlights other concerns. This wasn’t a one-time point exposure cause by some unusual event. Contamination of raw pet food with this concerning bacterium might be more common than has been previously recognized.

Whether these are rare cases or a small subset of actual cases is unclear. This cluster was identified because:

  • The infections occurred close together in time (within 1 month)
  • Public Health England does detailed whole genome sequence testing of E. coli O157 isolates
  • They have detailed case questionnaires
  • They looked for and found a link

Large outbreaks of disease in people involving the same E. coli O157 strain wouldn’t be expected from exposure to dogs fed diets where there’s probably a lot of small batches of the pet food produced and batch-to-batch variation with regard to contamination. Patterns need to be apparent to flag a potential problem, and sporadic cases aren’t as amenable to that. So, we don’t know if this was an exceptional event (i.e. infections are rare) or whether this was a matter of the right circumstances allowing for rare diagnosis of a more common problem.

My personal opinion here is based on seeing enough sick pets and sick people from raw diets. For that reason, I don’t like to see these diets fed. That’s particularly true in households with people or animals that are at higher risk of severe disease (i.e. young, old, pregnant, immunocompromised). If someone is going to feed a raw diet anyway, there are ways to reduce the risk to people and animals, both in terms of products that are purchased (e.g. high pressure pasteurization likely reduces the risk a lot, even though it doesn’t eliminate it) and how raw diets are handled in the home. More information about feeding raw diets and reducing the risk is available on the Worms & Germs Resources – Pets page.

The Canadian Food Inspection Agency (CFIA) has released new rules for importation of dogs less than 8 months of age for commercial purposes into Canada. The issues around canine importation have been increasingly prominent in recent years, and came to the forefront following an importation debacle in June 2020 that led to the deaths of dozens of dogs imported as part of a shipment from Ukraine last year.

The new rules are a good step. They don’t fix all the issues, they don’t address all imported dogs, and don’t seem to beef up penalties, but they should result in some improvements and hopefully a greater ability to get data about at least some of the dogs being brought into Canada every year.  The rules (for now) only apply to dogs under 8 months of age being imported for “commercial” purposes, including breeding, showing and most importantly sale/adoption. Although this is just a subset of all imported dogs, it’s a big one, as it includes commercially imported puppies like the shipment from the Ukraine last year.

Here is a summary of the main changes (you can also check out the “then and now” table from the CFIA for a side-by-side comparison with the old rules):

No more unlimited “multiple entry” import permits.

  • Previously, you could get a permit for multiple batches of dogs of undetermined sizes over a period of time. Now, you can only get single entry permits for a specific number of dogs.

Stricter rabies vaccination requirements.

  • Dogs must be vaccinated at least 28 days before shipping (previously there was no waiting period between vaccinating and importing a dog).
  • Since rabies vaccine can’t be given until 12 weeks of age according to label instructions, dogs will now have to be at least 4 months old before being shipped (although it doesn’t solve the problem of importers lying about the age of the dogs in a shipment…)

Mandatory treatment for internal and external parasites before departure.

  • That’s a good general practice for a number of reasons, so it’s great that it is now a requirement. Among other things, it helps reduce the risk of importing parasites along with the dogs, including foreign ticks or tickborne diseases. I haven’t seen the specific details yet, but the drugs used and timing of treatment relative to shipping will impact how useful this is.

Provisions for quarantine when needed.

  • We don’t have federal quarantine facilities and there was no provision for this before. Now, importers have to have an arrangement with a facility to quarantine imported dogs, if needed.
  • When quarantine will be required isn’t clearly defined, but if an issue is identified at arrival, it provides a mechanism to get the dogs quarantined and treated if necessary (at the importer’s expense) while the issues are assessed and resolved.
  • Notably, this only applies to dogs imported by air.

More organization required prior to arrival of the dogs.

  • Rather than just showing up at the border unannounced, shipments must be scheduled in advance to ensure adequate staff are available for inspecting the dogs on arrival.

Clearer rules around the kennel of origin.

  • The kennel where the dogs came from must be certified by an official vet of that country, indicating the kennel meets certain criteria specified by the CFIA.
  • This new rule still has a lot of potential loopholes and potential for corruption (e.g. if the dogs are transferred to a temporary facility before shipment, does that then become the kennel of origin?).  At least it’s an improvement on the previous rule and a step in the right direction.

Overall, I’d say the new rules are a good start, but let’s hope they don’t stop there. These changes won’t fix all the problems, but they should help.

The biggest issue that remains: Canadian consumers.

There would be no mass importation of poorly raised puppy mill dogs if people weren’t willing to put on blinders, avoid asking questions and pay thousands of dollars for a dog from a questionable source.