COVID-19 and Pets and Wild Animals: What’s Known and Not Known

People continue to be concerned or simply curious about dogs, cats and domestic ferrets and SARS-CoV-2, which causes COVID-19.

The good news is that diagnostic labs Antech and IDEXX have now tested thousands of dogs and cats with only (according to my count) two cats in New York State testing positive in the U.S. Add to this, a team of Tufts University researchers testing hundreds more animals looking for clues on whether they can get the virus and pass it along to humans, or vice versa – and no positives have been identified.

Scientists are certain that like the original SARS corona virus, this new novel SARS virus prefers cats to dogs. The cell receptors more easily “stick” in cats. However, with all the domestic cats tested worldwide, only minuscule number have tested positive for COVID-19. Due to potentially flawed testing methods, some presumed positives remain uncertain. For sure, a cat in Carver County, MN and another in Springfield, IL tested positive in addition to the two cats in New York State. A cat in Hong Kong and a cat in France have also been confirmed.  Few of any of these cats appeared sick; some had mild illness.

One recommendation is to keep cats inside

Dogs can get COVID-19 as well, though these events are even more rare. In early June, according to the United States Department of Agriculture’s (USDA) National Veterinary Services Laboratories (NVSL) the first confirmed case of COVID-19 in a German Shepherd Dog in New York state. This is the first dog in the United States to test positive for SARS-CoV-2. A German Shepherd dog and a Pomeranian in Hong Kong were also positive. A Pug in North Carolina which received tons of press and was originally thought to have the illness now likely turns out just to be a Pug that sometimes coughs.

Science on this continues to evolve – here’s what is known:

COVID is a human illness, and it’s exceedingly unlikely that a dog or cat will ever get the illness. If it happens in a dog, it’s a dead-end proposition. Dog with COVID-19 don’t get very sick (if sick at all) and the illness isn’t transmitted to other animals or back to humans. In cats, the story is a bit more complex. Cats also rarely get sick, and if they do get the virus, it’s SO likely also to be from prolonged close contact with a sick human.

However, at least one invitro (test tube) study demonstrates it’s possible for cats to transmit COVID-19 to other cats, but this theory has not proven to occur in the real world. A paper published May 13 in the New England Journal of Medicine, called “Transmission of SARS CoV-2 in Domestic Cats” reveals that cat to cat community spread of COVID-19 is possible – at least in their limited laboratory

study.

What About Wild Animals and pet ferrets?

Tigers at the Bronx Zoo

And it’s possible (though still unknown) if the Malayan tigers and African lions at the Bronx Zoo with COVID were infected by an asymptomatic keeper, or if one tiger (named Maya) was infected (the first tiger discovered with COVID-19), and then spread the disease to the other big cats.

However, animals in the family called mustelids, like otters, polecats, weasels, and especially mink are biologically more susceptible to SARS viruses. Due to outbreaks,  all mink on affected farms in the Netherlands have been culled. The concern is that minks may potentially transmit the disease back to people – though thus far this has not been reported. It seems some domestic cats have tested positive for COVID who live on mink farms. It’s not likely the two species would have contact with one another, since mink could try to eat the cats. Perhaps, it is the mink manure – though no one knows for sure how cats were infected.

Theoretically very susceptible – but so far so good with domestic ferrets

Domestic ferrets are also mustelids and there’s a real concern, but little is known. In a sense this is good – because there’s not been a problem with pet ferrets reported sick with COVID. It’s not surprising to see that ferrets are susceptible to SARS-CoV-2 infection, as described in a small pre-proof manuscript from the journal Cell Host & Microbe (Kim et al. 2020).

So far, no mustelid in a zoo has been reported as a positive. It’s also assumed that primates are likely susceptible, but zoos know that and have been careful. So far, no positives in monkeys, great apes, lemurs or other non-human primates.

How Rare is COVID-19 in Pets?

In all, around 35 or even fewer companion animals in the world have tested positive for COVID-19. Compare those numbers with (as of June 16) eight million people identified with COVID0-19 (and likely many more not tested or diagnosed)

Clearly companion have not proven a concern for their health as a result of COVID-19, or spreading the illness to other pets or to people.

Two VERY important points:

• If your pet is coughing, it’s is far more likely to be another cause and not COVID-19. However, if the coughing pet is spending time with a human sick from COVID-19 do contact your veterinarian. Of course, any ongoing cough should always be investigated by a veterinary professional.
• There is absolutely no reason to relinquish your pet out of concern that your pet will get COVID-19.

The American Veterinary Medical Association offers a comprehensive review of SARS CoV-2 and pets.

The Food and Drug Administration newly released video on COVID-19 and pets:

One Health

While it remains unknown where this novel corona virus was “hatched,” it appears likely to be from an animal market or so-called “wet market” in Wuhan, China. Animals in these markets are butchered on-site, in absolutely inhumane and unsanitary conditions. Wild animals who would never encounter one another in the wild are maintained in cages far too small and in close proximity; they are stressed – if not downright terrified. No wonder, illness occurs. And under these conditions illness can easily spread. Various bat species are among the animals maintained in these places and killed on site. Bats live quite well with a long list corona viruses (many are still not identified).

Dr. Jane Goodall

Dr. Jane Goodall and Sir David Attenborough are among those, including infectious disease experts worldwide, who have predicted these places will no doubt cause a pandemic. It was only luck that the first SARS (Sudden Associated Respiratory Syndrome) CoV-1 dead-ended in 2003, still 774 people died from 26 nations.

There is now a great deal to be learned from bats. For starters, understanding how they can live with corona viruses and not be affected. Scientists are studying a wide variety of species, from the llama, various shark species to the pangolin.

Many mammal species are prone to species-specific corona viruses. Cats and dogs have their own corona viruses. It turns out that the novel SARS viruses affecting people isn’t all that different (in many ways) compared to the feline corona virus. The feline corona virus is now so benign in cats, most don’t even get sick. Why is that?

In some cats (usually this happens in kittens) that benign corona virus mutates into an immune mediate disease, called feline infectious peritonitis (FIP), which had always been a death sentence. But no longer. A nearly identical drug to one that can treat FIP is called Remdesivir. After scientists investigated, Remdesivir became the first drug approved to treat COVID-19 in humans. A second drug is now being considered as a treatment to COVID-19, a compound known as GC376, which is now undergoing the approval process from the Food and Drug Administration Center for Veterinary Medicine to treat FIP.