Here’s an updated version of A Guide to Mitigating the Risk of Infection in Veterinary Practices During the COVID-19 Pandemic.

Also available through the Ontario Veterinary Medical Association website.

I’ll be happy when we can stop updating these guidelines. Progress is good and adding new information is useful. I just long for the day when we don’t need them.

I’ve taken a look back at some posts from the start of the COVID-19 pandemic, to see how my thoughts have evolved, what I got right and what I screwed up. We have a lot of COVID-19 posts (starting from when we called it “novel coronavirus” or “Wuhan coronavirus” before the SARS-CoV-2 terminology existed). Here are some highlights and “grading” of my comments from a selection of posts

January 20, 2020 “New coronavirus: Companion animal concerns?”: Very early on I said While this virus still seems to be less transmissible and less virulent than its relative, the SARS coronavirus, it’s pretty early to have a lot of confidence in that.

  • Grade B: It turns out SARS-CoV-2 is not less transmissible than the first SARS virus, but I guess I covered myself by saying it was early to have much confidence.

For containment measures for SARS, this new coronavirus or any other new disease, we need to assume that multiple species can be affected until proven otherwise, and we need to act accordingly. That doesn’t necessarily need to be complex. It might just be making sure animal contact questions are asked along with human contact questions, that quarantine protocols consider what to do with exposed animals, and that quarantined individuals are kept away from animals. 

  • Grade A: This turned out to be a fairly accurate statement, but fortunately risks from animals seem to be pretty limited (let’s hope this statement holds up). This is also around the time I sent some (essentially ignored) emails to try to get some consideration of animal aspects in any human exposure response planning here in Ontario.

January 23, 2020 “Novel coronavirus in China… Hold off on blaming snakes”:  In a post talking about how snakes might be the source of SARS-CoV-2, I wasn’t convinced and said I’m sure we’ll see much more genetic analysis of this virus by many different groups, but I suspect it will keep coming back to bats as the source. 

  • Grade A:  A final answer is still needed but this seems correct.

February 5, 2020 “Novel coronavirus and animals”: In talking about whether there’s actually a problem with companion animals, I said we need to focus on ensuring exposed animals are quarantined, using good old fashioned infection control like hand washing, keeping fear at bay and applying logic to the problem.

  • Grade B+: I’ll dock myself some marks on this one since it was focused on dogs. To be fair, the post was about concerns regarding over-reaction and euthanasia or abandonment of dogs, but it didn’t get into the bigger risks we now know are present with other species.

February 14, 2020 “More on COVID-19 (novel coronavirus) in animals”: I said We still have no evidence that this virus affects domestic animals, but since we also still have no real evidence that it doesn’t, it’s best to continue to take reasonable precautions to reduce the risk of exposure of animals to infected people, and to properly manage pets of people who are infected. “

  • Grade A+: Especially since it was at the same time groups like the US CDC were actively pushing back against there being any risk to/from animals.

February 18, 2020 “COVID-19 and potential animal hosts”: This post talked about a study that predicts species susceptibility based on ACE2 receptors. The potential susceptibility of cats is obviously a concern given their commonness as pets and the close interaction many people have with their cats. Pigs could be an even worse issue. If pigs could be infected and shed the virus, and it got into the commercial pig population, it would potentially be an even worse issue.  As with SARS, mice and rats are likely resistant to infection – that’s good from the standpoint of them not being reservoirs in the wild, but it also means they can’t be used for experimental study (as these are the most common lab animal species).

  • Grade C+: I think I over-estimated how useful these studies would be. They were interesting, but some species predicted to be high risk (e.g. pigs) aren’t, and some that were predicted to be lower risk (e.g. cat) most certainly as susceptible to SARS-CoV-2.  I also missed a couple of points. It seems like infection of pigs isn’t a concern but I think I missed some of the main potential concerns, as I wasn’t thinking about them as sources of virus mutants or wildlife exposure.

February 28, 2020 “COVID-19 in a dog”: A post about the first SARS-CoV-2 positive dog: Overall, my concerns are still more about cats. Dogs will probably get investigated more because there are more pet dogs than cats in most regions, and people tend to seek healthcare for the dogs (or alternative caretakers if the owner is indisposed due to illness) quicker than for their cats. 

  • Grade A: That turned out to be true.

March 27, 2020 “Human-to-cat COVID-19 transmission: Belgium”: I said If you’re worried about getting COVID-19, worry about your human contacts, not your pets. Keep pets away from high risk people, but otherwise, your risk is from exposure to people, not your pet

  • Grade A: I haven’t really changed that line in the past year.

March 29, 2020 “Social distancing WITHIN veterinary clinics”: I said Masks can reduce the risk of transmission if someone is unknowingly shedding the virus . Masks aren’t perfect but there can be some benefit. Whether it’s a good use of masks is questionable. Putting on masks for occasional close contact procedures (and ideally reusing that mask for the whole shift) isn’t unreasonable, but whether it’s really worth the mask use is hard to say.

  • Grade D: My line on masking was influenced by influenza data and concerns about mask availability, and I underestimated the usefulness of routine masking. I also focused on it being needed for known close contact situations, not more broadly. Those were the standard recommendations at that time but I still get a “D” for this one.

March 30, 2020 “COVID-19 and ferrets”: Here, I discussed concerns about ferrets.

  • Grade C:  We haven’t seen much SARS-CoV-2 activity in ferrets. Maybe that’s just because they aren’t common pets and don’t get taken to a veterinarian as often. Where I missed the boat was thinking about related species. Mink were not on my radar at all… (see below.)

April 24, 2020 “Pets and COVID-19 fears”: A commentary sent in partnership with the Ontario Veterinary Medical Association to veterinarians to balance awareness and paranoia when talking to pet owners about SARS-CoV-2.

  • Grade A: I’m not sure I’d change anything a year later.

April 26, 2020 “COVID-19 in mink: The Netherlands”: I said We’ll put this in the “interesting but not really surprising” file.

  • Grade C-: Fair statement, but while I talked about the concerns, I don’t think I really appreciated how susceptible mink would be and the issues that would develop from that.

April 28, 2020 “COVID-19 modelling and the impact of releasing cats”: This was a commentary about a crap-tastic paper about releasing infected cats and the potential impact on virus tranmission. Little did I realize this was one of many future “studies” based on little substance, little common sense and a complete abandonment of any principles of peer review. Academic opportunism has abounded in the past year and a bit, with some people putting out utterly useless papers, reviews and commentaries, and sometimes causing harm.

  • No grade… just a rant.

May 28, 2020 “Veterinary clinic staff cohorting”: I said One concept that we’ve recommended for COVID-19 control in veterinary clinics is staff cohorting.

  • Grade D: This turned out to be too impractical in most situations. It might have been useful if this was a short lived problem, but obviously that hasn’t been the case. I dropped this idea pretty quickly.

In the same post Routine cloth mask use whenever a 6-foot gap can’t be maintained between people is emerging as a key infection control tool. Cloth masks are far from perfect, but they can do a good job containing most infectious droplets, which are probably the main source of exposure.

  • Grade C: We now know the focus on the 6-foot distancing as a risk/no risk cutoff isn’t valid. Emphasizing mask use was good, but focusing on known close contact situations wasn’t.

I’d give a higher grade for the rest of the post. Most of it was actually pretty good, but these are some glaring issues.

I’ll pause here to avoid this post getting even longer. Overall, I think we had some pretty good thoughts about animals from the start. I missed the ball on a couple of key things:

  • Importance of masking: I mentioned masking above, but I didn’t realize how much of a core lifestyle component this would be.
  • Duration of the pandemic: I was expecting the pandemic to hit hard in the spring of 2020 based on modelling, so I wasn’t surprised at what we encountered then. However, I didn’t expect the pandemic to drag on this long. I was truly thinking we just needed to hit it hard in the spring of 2020 to return to normalcy in the fall or winter.

As spring approaches, a pressing question has come to the minds of many kids: “Can the Easter bunny get COVID-19?” or “Can Easter bunny eggs spread COVID-19?

Fortunately, the answer is no. Easter bunnies are safe from this virus and kids don’t have to worry about whatever the Easter bunny leaves behind.

Based on what we know to date, “regular” rabbits aren’t very susceptible to the SARS-CoV-2 virus.  Some types of rabbits can be infected with SARS-CoV-2 experimentally, but they don’t seem to get sick and they only shed low levels of virus. So, even a regular rabbit that was infected probably poses little to no risk.  (Don’t worry kids, no one’s going to try that with the Easter bunny.)

Furthermore, as we all know, the Easter bunnies have inherent magical properties that protect them from various problems (e.g. nosy household dogs). Their elusive nature (have you actually ever seen an Easter bunny depositing its wares?) and strategic placement of gifts in empty rooms mean the Easter bunny is following our “3 Cs approach to COVID-19 control,” that is avoiding closed spaces, close contact and crowded settings. And maybe the Easter bunny wears a mask too? We’ll probably never know for sure…

Don’t be afraid of the Easter bunny.

Don’t worry about what the Easter bunny leaves behind

No, you don’t need to disinfect Easter eggs.

The biggest risk from the Easter bunny is when the family dog finds all that chocolate first (yes, I am speaking from personal experience). That has nothing to do with COVID-19.

I tweeted recently about the first report of the B.1.1.7 SARS-CoV-2 variant being found in animals, specifically in a dog and cat in Texas, which deserves some more discussion. Also a new pre-print article (i.e. non-peer-reviewed paper) was posted recently that will probably raise more concerns, so I figured I’d better write about that one too.

Texas A&M Research Uncovers First Known COVID-19 UK Variant In Animals

The B.1.1.7 variant of SARS-CoV-2, which first emerged in the UK, is becoming widespread internationally and fueling third waves of COVID-19 in the human population in multiple countries. It’s more transmissible than “regular” SARS-CoV-2 and may cause more severe disease. Fortunately most of the available vaccines still seem to be effective against it, but it’s causing a lot of damage while we’re still trying to get enough people vaccinated.

It’s clear that people commonly pass SARS-CoV-2 to their pets. As this strain (and others) become more common in people, it’s inevitable that animals (particularly the pets we live with) will be exposed too. It’s unlikely (though possible) that the strain will be significantly less infective in animals than the original strain, so we fully expect to see it spillover into pets.  I assume there have been thousands of dogs and cats unknowingly infected with this and other variants of concern (VOCs) so far, but we test very few animals in COVID-19-affcected households. So, the Texas report was an expected confirmation that pets can also be infected with this VOC. We’re testing animals here in Canada too as part of our ongoing surveillance project.

Myocarditis in naturally infected pets with the British variant of COVID-19 (preprint)

This paper, which I will emphasize again has yet to be peer reviewed, will likely cause a bit of concern, but probably unnecessarily.

The authors observed an increase in dogs and cats presented to a referral veterinary clinic in the UK with myocarditis (inflammation of the heart). The concern was that the increase occurred at the same time the B.1.1.7 variant was surging through the human population in the UK.

  • Clinical observations of abnormal patterns are important. Most often, they end up being nothing remarkable – just random changes in normal events, or coincidences. Sometimes, though, they’re an early warning that something is going on. So, they are worth investigating.

Most owners of the affected animals reported having COVID-19 themselves in the 3-6 week period preceding the animals’ illnesses.

  • Interesting. Far from definitive (especially during a pandemic when lots of people are infected), but worthy of investigation.

They collected oro-nasal and rectal swabs from six cats and one dog with myocarditis in late January / early February. They also collected blood from these pets to look for antibodies against SARS-CoV-2. Blood samples were also collected from 4 other pets (2 cats, 2 dogs) that were recovering from myocarditis. None of the animals were reported to have had any respiratory disease.

  • 3 animals (2 cats and 1 dog) were positive on PCR for SARS-CoV-2 on rectal swabs, with a low viral load. All oro-nasal swabs were negative. The PCR test that was used indicated that the B.1.1.7 variant was present, although the test performance isn’t described.
  • Antibodies against SARS-CoV-2 were not detected in these 3 pets. That makes the results a challenge to interpret. Were the PCR results false positives, or were the serology results false negatives? It doesn’t seem like they followed up with later antibody testing of PCR-positive animals. That would help determine if they were antibody negative initially simply because they had not yet produced enough detectable antibodies (as that can take some time).
  • Three other animals (2 cats and 1 dog) had antibodies against the virus. Those animals were either PCR-negative (1) or PCR was not done (2).  If the serological test used was good (no information was provided on test performance or quality control), then I’d assume the PCR-negative, serology-positive animals had been infected at some point in the past.  PCR is only positive for a short period of time when the animal is actively infected and shedding virus, but antibodies can stick around for a long time after the infection is gone.

What does this tell us?

  • That some human-to-pet transmission of SARS-CoV-2 likely occurred (but we already know this happens).
  • The B.1.1.7 variant was involved (ditto).

Overall, 6/11 animals had some degree of evidence of exposure to SARS-CoV-2. That seems like a fairly high proportion, but it’s not far off the numbers we’re seeing with our work and work from other groups in healthy animals from COVID-19-positive households. So this does not provide any evidence of a link between SARS-CoV-2 infection in pets and myocarditis. Nonetheless, I wouldn’t dismiss it, and we should look into it more.

The authors’ statement that “the discovery of B.1.1.7 infected cats and dogs highlights more than ever the risk that companion animals may potentially play a significant role in SARS-CoV-2 outbreak dynamics than previously appreciated” has no substance. This study just showed that animals can be infected. It does not indicate anything about pets’ role in outbreak dynamics or anything else. We don’t want to ignore the potential that cats, in particular, could transmit the virus. However, their conclusion is unsupported and unlikely to be true.

I’m fully on board with their last statement, though: “Therefore, there is an urgent need to greatly accelerate and strengthen the investigations and surveillance of animal infections by highly-transmissible variants such as British B.1.1.7, South-African B1.351 and Brazilian P.1 variants as part of the global response to the ongoing multi-species COVID-19 pandemic.”

We partnered with the Canadian Academy of Veterinary Dermatology to update our MRSP fact sheets for pet owners, including a new look, and a French translation!  Access them using the links below, or on the Worms & Germs Resources – Pets page.

What is methicillin-resistant Staphylococcus pseudintermedius? (English)

Qu’est-ce que le Staphylococcus pseudintermedius résistant à la méthicilline? (Français)

Here’s a pot pourri of reports of staphylococcal infections in humans linked to dogs. Specifically, they’re infections caused by Staphylococcus pseudintermedius, a common dog-adapted species of Staphylococcus. (If you get freaked out reading these, make sure you read the end of the post so you also get the context.)

A 41-year-old man with a history of skin disease and receiving parenteral nutrition (i.e. being fed intravenously) presented with fever, and developed a recurrent infection of the access port of his indwelling intravenous catheter. Staph pseudintermedius was isolated from him and his dog. They recommended he get rid of his dog.

  • It doesn’t sound like they recommended any other infection control measures, and the person did not get rid of the dog initially. He later did, after being hospitalized from the infection.
  • It’s impossible to say, but I suspect there were other (better) ways to reduce the risk of transmission in the household rather than have the patient get rid of his pet, especially if the dog was an important part of his life.

A hemodialysis patient with an indwelling intravenous catheter developed a S. pseudintermedius infection.

  • The authors stated, “Catheter care education should include information about pet exposure and the possibility of zoonotic infections.” I can’t access (aka I’m too cheap to spend the $37 access fee for) the full paper, so I couldn’t see what details were provided.

Infection of an implanted port catheter system by methicillin-resistant S. pseudintermedius (MRSP). MRSP is basically the dog version of methicillin-resistant Staphylococcus aureus (MRSA).

  • The MRSP strain was a type that’s commonly found in dogs internationally.
  • The person was a dog owner, but they didn’t investigate the pet dog and they don’t say anything about infection control measures in the paper.

A 56-year-old woman with rheumatoid arthritis, osteoporosis and common variable immunodeficiency developed a S. pseudintermedius infection of bone and soft tissue after surgery to repair a broken arm.

  • The same bacterial strain was subsequently also isolated from the patient’s pet dog.
  • No high-risk behaviours (e.g. dog licking face or broken skin, dog sleeping in the bed) were reported.
  • The patient had another dog that had a septic tooth and was being treated with an antibiotic, but it died before they were able to get samples. There’s no more discussion of that, but I wonder whether she was the one giving the dog oral medications and had exposure to the dog’s saliva that way. It’s possible the sick dog harboured the same bacterium as its housemate… maybe even more likely, since antibiotic treatment is a risk factor for MRSP in dogs. That’s all highly theoretical, obviously.

A 39-year-old woman receiving peritoneal dialysis developed septic peritonitis (i.e. infection of the abdominal cavity) with (you guessed it) S. pseudintermedius.

  • Peritoneal dialysis (PD) uses an indwelling catheter that goes from the skin into the abdomen.  Infections are the main complication associated with these devices.
  • The patient had a dog that slept in her bed, having close contact with the dialysis catheter.
  • While vague, the authors did address basic infection control issues: “No recurrent infections have been noted since admission with better hygiene and some distance with the pet dog.” and “Furthermore, PD training and ongoing education programs are needed for pet owners to help decrease the risk of PD-associated bacterial peritonitis. “
  • That’s what I want to see – awareness and education, not ignoring the issue or knee-jerk recommendations to get rid of the pet.

The main take-home message from all this: Relax, and wash your hands.

Is S. pseudintermedius a bigger threat now than in it was years ago?

  • No. It’s not likely any more able to infect people than it could in the past. Most dogs harbour the bacterium on their skin and/or in their mouth, nose and intestinal tract. Millions of people are exposed it every day. Yet, infections are very rare. It’s something to be aware of but we shouldn’t over-react.

But there are many more reports of human disease caused by S. pseudintermedius. Are zoonotic infections increasing?

  • Probably not. I suspect it’s a function of better identification of the bacterium by human diagnostic laboratories (they could have misdiagnosed it as a common human staph in the past), and proliferation of journals that will publish single case reports. I’d wager it’s more of an increase in publications than an increase in disease.

Is MRSP from dogs a bigger threat now?

  • Sure, because it’s much more common in dogs than it used to be.
  • However, MRSP is no more likely to spread to people than susceptible S. pseudintermedius, it’s just harder to kill when we have to treat it. It’s an important bug but human infections seems to be rare.
  • We can’t ignore MRSP, but it likely doesn’t crack the top 10 list of things I’m concerned about your average dog and cat transmitting to a person.

So, what should we do?

Staphylococcus pseudintermedius is a bug that’s found in and on most dogs. Most of the time, it doesn’t do anything to us when we encounter it. We have barriers like our skin and immune system to fight off such foreign invaders. When those barriers are compromised, the risk of infection goes up. Preventing infections comes down to very basic precautions like:

  • Hand washing
  • Limiting contact with saliva, nasal secretions and feces.
  • Keeping open wounds or invasive devices (like catheters) away from animals, and in particular, their secretions. (For me, here’s where there’s a difference between sleeping in the bed and sleeping on the bed. I’m ok with an animal sleeping on the bed if there’s no direct contact with the person. If it’s sleeping under the covers with someone, that creates ample, longterm contact for transmission of pathogens.)
  • Good, prompt wound care after any bite or scratch.

One last thing that often gets forgotten: People should make sure their physician knows they have contact with animals, and physicians should ask about animal contact. Most of the time it’s not relevant, but it only takes a few seconds and can provide important information in certain cases.

More information about MRSP can be found on the Worms & Germs Resources – Pets page.

Ontario Animal Health Network Veterinary PodcastsThe companion animal Ontario Animal Health Network has produced a series of mini-podcasts on COVID-19 precautions in veterinary clinics, featuring none other than Dr. Scott Weese.  Each mini-podcast features a quick 3-5 minute “lighting round” on common questions and topics – bite-sized bits for busy practitioners and clinic staff who may only have a few minutes to spare these days.  Current topics include:

  • Avoid the 3 Cs: Crowding, close contact, confined spaces
  • Rethinking clinic spaces: The end of the waiting room and more
  • Masks and the trouble with bubbles
  • Patients and procedures that warrant extra precautions
  • Don’t panic! Talking to clients about SARS-CoV-2 risk to and from pets
  • Staying safe with the swiss cheese approach
  • What’s on your face? The why, when and what of masks and face shields

If you have a COVID-19 related question about which you’d like to hear a podcast or mini-podcast, you can email OAHN at  Also check out the OAHN COVID-19 resources page for veterinarians. Stay safe!

I’m always on the lookout for good-looking, easy-access resources to help communicate (and to help others communicate) messages around safe and responsible pet ownership, which is how this blog got its start!  I also don’t like re-inventing the wheel when I don’t have to, and I appreciate that many organizations have people with vastly better design and layout skills than my own ;)

During the COVID-19 pandemic, the concern around the risks of SARS-CoV-2 both to and from pets (and trying to figure out exactly what those risks are) has certainly highlighted some of the basic infection control measures we recommend around pets (especially dogs, cats and ferrets), like hand hygiene.  There has also been a huge surge in puppy and kitten adoptions, which means lots of new pet owners out there who may benefit from some extra guidance and a few quick tips.

The US Centers for Disease Control (CDC)’s Healthy Pets, Healthy People website has come a long way over the years, and now has some really nice content that can be readily shared with pet owners (including prospective pet owners), linked to websites, and even shared on social media.  A few items that are worth checking out include:

Lyme disease vaccine is a non-core vaccine, meaning it’s not needed for all dogs in all areas. It’s an effective vaccine, and I’d consider it a reasonable vaccine to give to dogs in (or visiting) higher risk areas, especially when there might be owner compliance issues with tick preventive medication. Available tick preventatives are very good, but sometimes people forget to give them on time, so vaccination is a good backup plan for those situations and in areas where the risk of exposure is particularly high.

Lyme disease vaccines are a bit unusual, in that they are primarily aimed at vaccinating the tick, not the dog (strange as that sounds). They usually target two proteins on Borrelia burgdorferi , the bacterium that causes Lyme disease. One of those is outer surface protein A (OspA), which is “expressed” on the  surface of the bacterium when it’s inside the tick. After the tick has attached to a host (like a dog) for a while, the bacterium changes to make itself more adept at infecting animals. That results in a change in the outer surface protein from OspA to OspC.

Lyme disease vaccines contain OspA, which induces the dog’s immune system to produce antibodies against that protein. When a tick starts to feed, it ingests the antibodies in the dog’s blood, which attack the bacterium before it’s ready to migrate to the dog.

Lyme disease vaccines can also contain OspC, to target the bacterium in the tick as it starts to produce that protein, and provide backup protection if the bacterium happens to evade the OspA antibodies and makes it into the body.

With typical vaccines, if an individual is exposed to the bacterium/virus for which they’ve been “primed” by the vaccine, they then get an immune response boost to generate even more antibodies. However, that doesn’t really apply to Lyme disease.  Since the dog’s antibodies flow into the tick, there’s no extra immune boost because the bacterium isn’t yet in the dog’s body (so the dog’s immune system doesn’t get exposed directly). Decreased antibody levels in the dog therefore more directly correspond with decreased protection. There will be some booster effect with exposure to OspC if the bacterium makes its way into the dog, but ideally we’d like to stop the process before it gets that far.

Lyme disease vaccines are given as an initial series of 2 doses, 2-4 weeks apart, and then an annual booster. But,  there’s concern that immunity from Lyme disease vaccines doesn’t last as long as others, so there’s less leeway for overdue dogs. It’s been recommended to re-start the 2 dose series from scratch if the dog is overdue for it’s yearly booster by more than 1 month. That’s pretty conservative, but it’s fair to assume that this vaccine’s long-term protective effect could be less predictable and solid than leptospirosis vaccines (where we accept up to 3 month delay).

Based on that, when it comes to Lyme disease vaccines, if a dog gets its:

First dose, but is late for the 2-4 week booster

  • Restart the whole series (i.e. 2 doses 2-4 weeks apart, then yearly)
  • We don’t have good guidance on what constitutes “late” or “overdue” here.  The American Animal Hospital Association vaccination guidance says within 6 weeks of the first dose is still okay, and that’s reasonable. It’s quite possible that the dog would respond well to a later booster, but we don’t have confidence in that.

First dose, 2-4 week booster, and then a yearly booster not more than 1 month late

  • Continue with the single annual boosters

First dose, 2-4 week booster, but is more than 1 month late for the yearly booster

  • Restart the whole series (i.e. 2 doses 2-4 weeks apart, then yearly)

As I mentioned above, tick prevention is still key, particularly for unvaccinated or inadequately vaccinated dogs. If vaccination has lapsed, it’s even more important to avoid ticks, do tick checks and use a good tick preventive medication (on schedule).