This one’s bound to attract a lot of attention, and that can be both good and bad. A tiger at New York’s Bronx Zoo has tested positive for SARS-CoV-2. The tiger was sick (cough, decreased appetite) and was presumed to have been infected by a caretaker who was infected but asymptomatic. Three other tigers and three African lions also had a dry cough, but only one tiger was tested because sample collection in these animals requires general anesthesia.  All the affected big cats are expected to recover.  The zoo has been closed to the public since March 16, but the first signs of illness weren’t seen until March 27.

On one hand, it’s not too surprising. If domestic cats are susceptible, wild cats should be too.  On the other, there are some noteworthy aspects:

  • Zoo cats generally don’t have much direct contact with their caretaker (though this varies by zoo). Infection of these cats was therefore presumably through very transient direct, or indirect, contact.
  • Given the very limited testing of domestic cats to date, this yet again raises the question of how commonly domestic cats have been infected by owners in North America, given the large number of infected people and relatively high percentage of households with cats, and the much closer contact between people and pet cats (compared to zoo cats).

As always, don’t over-react. This just reinforces the message I’ve been saying since the January (which, despite all our talk about “One Health” led to a lot of criticism): We need to consider and investigate the potential animal aspects of this disease, such as human-to-pet transmission, in order to help prevent pets from contributing to human disease, and to help avoid creating a (domestic) animal reservoir for this virus. This is still a very much a predominantly human disease, but we can’t completely ignore the role of animals even if it’s small. We can use simple, practical and basically free measures to reduce the presumably low risks to and from animals, and we should:

  • If you’re infected, limit contact with animals.
  • If someone in your house is infected, keep your animals away from other animals and people.
  • Social distancing includes your pets. Keep your pets away from other people and animals outside your household, just like you should be doing with yourself.

Here is an updated version of the decision tree for screening of owners / patients coming to veterinary clinics, which I originally posted a few weeks ago, to help with identifying higher risk situations. We also have a Russian translation courtesy of Dr. Varvara Solovyeva.

You can use the links below to download the pdfs:

I think most people agree that the best thing we can do with pets of people with COVID-19 is to keep them in the home with the owner. However, what do we do with someone’s pet if they have to be admitted to the hospital and they live alone?  Someone needs to take care of the pet.  But who, and how? That’s a contentious topic.

The risk posed by that pet to someone outside the household isn’t clear. The risks are presumably greatest with ferrets and cats, and risks from dogs are probably pretty limited and short-term. But, since we can’t say the risk is zero, we want to keep things contained as much as is practical.  Hong Kong’s approach of isolating and testing exposed pets isn’t going to be common, so we need another plan.

The main goal is to reduce contact of the animal with new people and new environments. Additionally, we want to make sure the animal stays away from people that are high risk for serious disease (e.g elderly, people with underlying respiratory disease or compromised immune systems, diabetics, smokers). That’s not always possible, but here is my take on some options, based on what we know to date.

Continued care in the pet’s household by someone who has recovered from COVID-19 (e.g. recovered family member goes to the house every day to care for the pet)

This may be the best scenario, since it appears that once you get over COVID-19, odds of a new infection (at least in the short term) are very low. If someone who has recovered can come into the house as needed to care for the pet, that keeps it contained and away from susceptible people.

Care by someone who has recovered from COVID-19 in the caretaker’s household

This is a good option too, assuming no one else in the caretaker’s household is susceptible (i.e. any other household members have also already recovered from COVID-19). It’s more convenient and the risk posed by moving the animal into a new house with non-susceptible people is probably inconsequential.  Preferably the household doesn’t include any other pets either, or there’s a way to make sure the animals are kept in separate areas from each other.

Care by someone who has also been exposed (e.g. family member that doesn’t live in the household but had close contact with the sick person)

As the pandemic progresses, we’ll have more people who have recovered. However, not everyone will have a recovered person available to help. If a close friend or family member of the pet’s owner has already been exposed, bringing the pet into their household adds some risk (since the person hopefully hasn’t been infected) but less than bringing it into a household with no previous exposure (where the people are even less likely to be infected). From a pet containment standpoint, it would be ideal if the pet stayed in its own household and the exposed person went there to take care of it; however, the exposed person should be self-isolating and therefore not leaving their own house for 14 days. An exception might be if it was an immediate neighbour, where going next door poses no risk of exposing anyone else, but that would ideally be figured out with public health authorities.

In any situation, I would not want an exposed pet to be brought into a household where there were high risk people.

Care by someone who’s not recovered or exposed

This is less desirable since you’re bringing an unexposed person (or at least one that’s not known to have been exposed) into the situation. If that person is low risk for serious disease and doesn’t have high risk people at home, that helps. This situation increases the risks, though. The best approach would be short term, controlled visits to the pet’s household, just for basic animal care, and ideally wearing some form of personal protective equipment (especially for the first couple days – after that, at least there wouldn’t be any significant concerns with contamination of the pet’s haircoat). By keeping the duration of contact short, controlling the type of contact, and using good hygiene practices (especially hand hygiene), exposure risks can be limited.

Taking the animal into the new caretaker’s household increases the risk because the pet and the person will likely have increased duration and closeness of contact, and there’s less ability to use barriers and hygiene around any contacts. If the animal can be kept in a cage or crate all or most of the time, or at least for the first few days to negate coat contamination concerns (not ideal for the pet but reasonable in the short term), that would help.

Other options

If the “friends, family and benevolent neighbour” approach isn’t an option, then it gets trickier. Temporarily transferring the pet to a shelter would be a consideration, if the shelter is able and willing to handle potentially contaminated or infected pets, but that varies.  There’s been a lot of planning by shelters for this contingency.

Vet clinics are another option. However, it’s not ideal given the limited isolation capacity in most clinics, as well as limited staffing and operations in some. Clinics that have the facilities, personnel and comfort with handling infectious cases would be an option. (We are set up to handle potentially infectious cases like this, but even our facility can only handle a limited number of animals.)

If exposed animals have to be moved from a household where there was a person with COVID-19, a bath or disinfectant wipe of the haircoat is reasonable to try to reduce any risk from contamination of the haircoat. We have no idea if this is a real risk, but the virus would presumably survive for some time on a hair coat if deposited there by the owner. How long? We don’t know. Probably minutes to hours, but that’s unclear. That’s why bathing and some additional short term precautions (e.g. cage/crate) might help. After a couple of days, we just need to worry about whether the animal is truly infected. We still don’t understand how common that is, or whether an infected animal can infect a person. Hopefully we’ll sort that out more soon. I’m set up to do surveillance on exposed animals but it’s been very difficult getting into households to get samples, for obvious reasons. As we learn more about how commonly or rarely exposed animals are infected, we can refine our recommendations. For now, it’s a tough balancing act between being prudent and practical.

A couple of new guideline documents have been released.

First up, a Canadian COVID-19 FAQ for veterinarians, created by a working group of Canadian public health and animal health experts (French translation to come).

Also, there’s a revised version of animal shelter guidelines from the US: “Interim recommendations for intake of companion animals from households where humans with COVID-19 are present”, a collaboration of the American Veterinary Medical Association, University of Wisconsin-Madison Shelter Medicine Program, the Association of Shelter Veterinarians, University of California-Davis Koret Shelter Medicine Program, University of Florida Maddie’s Shelter Medicine Program, and the CDC COVID-19 One Health Team.

Based on what we knew from the original SARS virus and the similarity with SARS-CoV-2 (the cause of COVID-19), we expected ferrets to be one of the species that could be susceptible to infection with the latter. When ferrets were infected with the SARS virus, they got sick (unlike cats that just shed the virus). Various experimental studies are underway internationally to look at susceptible species, both to understand the virus but also in large part to develop an experimental model (for things like vaccine research).

So, it’s not surprising to see that ferrets are susceptible to SARS-CoV-2 infection, as described in a pre-proof manuscript from the journal Cell Host & Microbe (Kim et al. 2020). It’s a small but important study.

The short version:

  • Ferrets were experimentally infected and developed fever, lethargy and cough.
  • Ferrets in direct contact with infected ferrets got sick too.
  • Ferrets in adjacent cages got infected (i.e. virus was passed to them) but they didn’t get sick, showing that the virus was spread by indirect contact, but that the amount of virus spread this was was probably low and not enough to cause disease.

The longer version:

  • They inoculated 2 ferrets intranasally with the virus. Two days later, they put some uninfected ferrets in the same cages and put some other uninfected ferrets in adjacent cages.
  • This was repeated three times (6 infected and 12 exposed in total, plus 6 uninfected ferrets as controls).
  • Blood, nasal washes, saliva, urine and feces were tested for the presence of the virus every other day for 12 days.
  • After inoculation, ferrets developed a fever, decreased activity and occasional coughs. None died. Virus was detectable by day 2 after infection and viral levels were highest in nasal secretions. (That’s not surprising.)
  • Peak viral levels were on day 4 and persisted to day 8. All were negative at day 10. In addition to nasal shedding, lower levels of virus were found in saliva, feces and urine on days 2-8. Low levels were found in blood for a shorter period of time.
  • In addition to detection of viral nucleic acids (i.e. not necessarily live virus) by PCR, live virus was also isolated.
    • That’s not surprising since infected ferrets were able to pass the virus on to other ferrets, but is an important finding nonetheless. Studies that involve PCR always end up raising questions about whether live or dead virus was detected. Virus was also found in tissue samples from another group of infected ferrets. Overall, there’s no doubt these ferrets were truly infected.
  • All 6 ferrets that had direct contact with the infected ferrets developed fevers and decreased activity. These ferrets were all infected, as virus was detected in nasal samples by day 4 after they were put into contact with the experimentally infected ferrets. Virus was also found in saliva and feces.
  • None of the indirect contact ferrets (those in adjacent cages) showed any signs of illness. However, they were infected.  This raises a few interesting points:
    • One is the potential for aerosol transmission (the authors say “airborne’” but I assume that’s unlikely and I’ll bet  there will be some debate over their use of that term).
    • The other is that the lower level of exposure from indirect contact possibly accounted for the lack of disease (although we can’t get too carried away with conclusions based on what happened to 6 healthy adult ferrets).
  • By 12 days after infection, all ferrets were back to normal.

This study was focused on seeing if ferrets would be a good experimental model (and it looks like they would be, getting consistently sick but not seriously ill).

What does this mean for pet ferrets and their owners?

Not much beyond what we’ve already said.

  • If you’re sick, stay away from your ferret.
  • If a ferret is exposed to an infected person, keep it away from other people (and other pets).
  • Veterinarians should continue to ask owners about household COVID-19 exposure to help protect themselves from the owners, but also to consider potential issues when caring for their pets.

A cat in Belgium, owned by a person with COVID-19, has tested positive for the virus. The cat developed diarrhea, vomiting and respiratory difficulty about 1 week after the owner got sick, and SARS-CoV-2 was found in the cat’s feces. It’s not clear whether the test used was PCR (which can detected live or dead virus) or virus isolation (which only detects live virus), or if other samples were also tested. It’s also not clear whether the cat was sick because of the infection with SARS-CoV-2 or whether it had some other co-incidental problem (or whether the cat is still alive or not).  They were clear that this is another suspected case of human-to-animal transmission, and not the other way around.

Is this surprising?

Is this concerning?

  • I don’t have any more concern today than I did before this report, since it was likely that this was going to happen, and animals (still) presumably pose very limited risk. An infected cat isn’t a big concern in the household since the person who exposed the cat in the first place is the main risk. This virus is being transmitted very effectively person-person, so animals likely play little role, if any in the grand scheme of things.  But we still want to take basic steps to keep the risk as low as possible.

So, what do we do?

  • The same thing we’ve been saying all along. If you’re sick, stay away from animals just like you would other people. If you have COVID-19 and have been around your pets, keep your pets inside and away from other people. While the risk of transmission to or from a pet is low, we don’t want an exposed pet tracking this virus out of the household (just like we don’t want an infected person doing that).

This is completely unsurprising. It doesn’t mean things are changing or that we have more risk today than yesterday. It just emphasizes again the importance of paying attention to basic infection control measures.

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.

Much has been reported about the 17-year-old Pomeranian in Hong Kong that was the first dog to test positive for SARS-CoV-2, the virus that causes COVID-19.  It was positive on a series of PCR tests on nasal and oral swabs over the first week it was in quarantine.  They also collected blood samples to test for antibodies against the virus. The blood first tests were negative, which wasn’t too surprising, but was taken by some to mean the dog wasn’t infected (just “contaminated” with virus such that there was no immune response). However, subsequent testing of a sample taken back on March 3 showed that the dog did indeed produce antibodies against the virus, and therefore was definitely infected at some level.  Unfortunately, as previously mentioned, the dog died a few days after being released from quarantine (it’s not suspected that its death had anything to do with its infection with SARS-CoV-2).

The update from the Hong Kong Agriculture, Fisheries and Conservation Department also provides some more information about other testing they’ve done to date. They have tested 17 dogs and 8 cats from households with human COVID-19 infections, and two of the dogs tested positive.  It’s interesting (and encouraging) that no cats have tested positive so far, since I’ve had more concerns about the susceptibility of cats, but finding positive results in 2 out of 17 dogs definitely tells me we need to study this more.

This report  doesn’t tell us whether dogs and cats are a source of infection, because being infected doesn’t necessarily mean an individual is infectious (i.e. able to pass the virus on). We need to test more animals to see how common infection is and whether live virus can be recovered from infected animals. Unfortunately getting samples from households of infected people with pets has been a challenge due to the social distancing and human-to-human transmission concerns (which are clearly paramount).

I’ve written a lot about COVID-19 issues in veterinary medicine, but most of that material has focused on brick-and-mortar practices. There are lots of mobile veterinarians out there too, and they have different challenges with COVID-19.  Small animal mobile veterinarians are at increased risk of exposure because they go into households where they can’t use many of the social distancing practices that we can use in a standard veterinary clinic.

Many of these veterinarians are asking what they should do. Like most things pertaining to this virus, there’s no straightforward answer. The easiest way to prevent risk of exposure is for mobile veterinarians to stop doing house calls, but that’s not necessarily the best thing for veterinarians, owners or pets. The real questions relate to what can be done to reduce risks, what risks remain and how much risk is acceptable (to those directly involved and broader society).

There are lots of things that can be done, but I’d say the two most important considerations are 1) screening for high risk people in the household and 2) having an assistant.

Identification of high risk households

This may be the most important protective measure, and it’s similar to what many clinics are doing. It involves identifying households where COVID-19 risks are higher by calling clients in advance to confirm no one has COVID-19, is self-isolating or has acute respiratory tract disease. If any of these risk factors are present, the appointment should be rescheduled, the patient can be diverted to a veterinary hospital (where things can be contained better), or the mobile visit can go proceed using enhanced social distancing and infection control measures. This doesn’t eliminate risk completely, because there’s always potential for asymptomatic infections and shedding of the virus before someone shows signs of illness, but it helps a lot.

Personnel

Mobile veterinarians can’t do it all themselves (though they can do a lot!). Someone has to help restrain the animal for procedures. If the owner is the one restraining the pet, this results in unavoidable close contact between the owner and vet. That’s not ideal.

If a mobile vet has a technician or assistant with them, that’s much better because the owners can be largely, or completely, removed from the equation. The pet can be handed off on arrival, the vet and tech can do their work, things can be discussed with the owner at a distance, and ultimately the job is done without much difference from the usual routine.

Yes, the vet and assistant will have close contact throughout the day, but that’s unavoidable. I’d rather have multiple contacts with one person than contact with multiple people. That is IF (any only if) that person takes social distancing seriously, even outside of work.  When there are situations at work when you can’t maintain that social distance, it is critical that everyone does it properly at all other times to decrease their risk of exposure.  If I’m exposed to one person regularly during the day, I have a responsibility to be diligent with social distancing outside of work to protect myself, my family AND that close occupational contact.

Social distancing

The whole concept of social distancing is to reduce the number of human-human contacts and the closeness of those contacts. If we can prevent direct contact and stay 2 metres away from others, the risk of transmission of the COVID-19 virus (and a lot of other pathogens) drop greatly. Trying to maintain that distance during a house call means choreographing movements a bit and having owners keep other people (e.g. rest of the family) away so there’s less chance of accidentally invading anyone else’s “bubble” .

Depending on the household and weather, there may be ways to reduce contact with the household environment too, such as examining the animal in a garage, on a porch or somewhere outside. There’s a balance between avoiding the household environment but also being able to effectively and safely work with the patient.

Self-screening

“If you’re sick, stay at home” has been a message for years, but it’s been largely ignored in the past – not anymore, and it’s now critical. Mobile vets have to do their part to avoid spreading this virus. Some are taking their temperatures every morning, which is an easy and free screening tool for them. If a vet or assistant isn’t feeling well, a self-screening tool like Ontario’s online COVID-19 self-assessment should be done. However, if in doubt, stay home. Even if you are sick because of something else entirely, we don’t want to spread colds or flu or anything else, and clients will certainly be unimpressed if a vet is coughing, sneezing or looking rough when they show up.

Animal handling

There’s been a lot of discussion about the potential for a pet’s haircoat to be contaminated with COVID-19 virus and be a source of infection, but we have basically zero data either way.  There’s presumably some degree of risk. However, it’s only relevant if the animal is in a household (and in contact) with an infected owner. So, if we are already screening to identify high risk owners, we drop the potential haircoat contamination concerns a lot. Beyond that, it’s a question of balancing practicality, prevention and personal protective equipment (PPE) supplies. I don’t think we need to bring out enhanced PPE for every animal contact, we just need to use good routine infection control measures. I’d rather save my PPE for when it’s clearly needed, to make sure I still have some.

Infection prevention and control

It’s not rocket science, but good old infection control, particularly hand hygiene, is critical on house calls too. We rely on routine practices to protect ourselves when we run into unknown or unexpected risk situations. Even if there was SARS-CoV-2 on a surface in a household, as long as I wash my hands or use a hand sanitizer after I touch it, the risk I’ll get infected is low. Other routine precautions like wearing proper protective outerwear (e.g. lab coat) over regular clothing, limiting the supplies brought into the household to the essentials, and routine cleaning and disinfection of equipment are also relevant.

Other measures

Some of the alternative approaches and measures outlined in our recently posted  guidance document on elective vs essential procedures, patient handling and social distancing in veterinary medicine apply to mobile practice as well, including things like making more use of telemedicine, drug/food drop-offs, and  reducing the need for signatures.

Essential vs elective

The other big question around mobile practice is “what can (or should) I do?” Different states and provinces have taken different lines around veterinary medicine and what’s essential. Some aspects of small animal mobile veterinary medicine certainly fit in the essential category, but it warrants some thought. We want to consider animal care, animal welfare and owner welfare, while remembering the need to be socially responsible, maintain social distancing and keep an eye on supply shortages. Scaling back to only clearly low risk households and essential visits makes sense at the start, as we see how this pandemic progresses and how supplies hold out.

Yet another longer-than-ideal post, but there’s a lot of questions (and a lot of angst) about this subject. We’re figuring things out as we go, but some common sense can protect us and help with animal care and owner support.

It’s still an evolving area with many unknowns, so definitive statements about COVID-19 and animals are often lacking.  We realize we might change some recommendations as we continue to regularly re-assess the evidence. Nonetheless, here’s the most recent information for the public on COVID-19 and animals from the Government of Canada (specifically the Canadian Food Inspection Agency).

Animal Health and COVID-19 – CFIA (English)

Santé animale et la COVID-19 – ACIA (Français)