COVID-19 and Animals: What YOU Need to Know

[David Baxter PhD]

COVID-19 and Animals: What YOU Need to Know. Part One.
Bruce Roney, President & CEO, Ottawa Humane Society
November 19, 2020

Did you know, one of the world's top experts in infectious disease in animals lives in Ontario? Dr. Scott Weese is the former Canada Research Chair in Zoonotic Diseases at the University of Guelph and a veterinary internal-medicine specialist and chief of infection control at the Ontario Veterinary College. He writes an outstanding blog, called Worms and Germs that I follow regularly. He is a great friend of the Ottawa Humane Society and has always made himself available for any information we need.

Over the past several weeks, in his blog, Dr. Weese has summarized what is known about COVID-19 in various species.

Dogs and COVID
Dr. Weese responded to the news reports of two outwardly healthy dogs in the Niagara region who tested (mildly) positive for the virus. Four people in the household had COVID-19. The family is now recovered. Still, the case raised concern in some circles.

So, what does Dr. Weese conclude about what this means for the family members? Nothing. He writes, "The people in the household were all infected, and that was almost certainly human-to-human transmission. The dog(s) were infected by the owners and at that point didn't pose any risk to the already-infected people."

What about other risks? Dr. Weese writes, "The potential risk from pets is if they have contact with other people or animals outside the household, such as going to parks, kennels or veterinary clinics. We don't know if dogs often shed enough virus to be infectious to others. We've been going on the assumption that dogs are low-risk for being infectious, and I don't think this changes anything. However, we certainly can't say there's no risk…"

As to neighbours, "There's also a plausible risk of transmitting virus to neighbours through the fence. Consider pets part of the household in terms of COVID-19 precautions. If people are being isolated, do the same with pets. It doesn't matter if a dog or cat is infected if they don't encounter anyone new."

Cats and COVID
Dr. Weese reviewed a number of published and yet-to-be-published research papers on cats and concluded:

• Cats are susceptible to the virus
• Most often, infections are likely subclinical (i.e. cats stay healthy)
• Just like in people, some cats can get sick, including (rarely) fatal illness
• Cats can spread the virus cat-to-cat, so we have to consider cat-to-human transmission a possibility (however uncommon)
• Most cats that get infected are directly infected by their owners

So, Dr. Weese poses the question, should we worry about SARS-CoV-2 in cats? "Worry, no. But we should pay attention to it. There's a cat health risk, and we want to avoid that by reducing contact of infected people with cats…" He advises, "When you have someone isolating from the rest of the household (e.g. living in the basement), we want to make sure pets like cats are considered, so they're not tracking the virus from the infected person to the rest of the family."

For protecting against transmitting COVID-19 to your pets, Dr. Weese recommends using a common sense approach. If you're infected with COVID-19, limit your contact with anything with a pulse (not just people). If your household is isolating because of COVID-19 exposure, make sure it encompasses the whole household - furry family members included.

At the end of the day, Dr. Weese says the same thing about pets and COVID that the Ottawa Humane Society has been saying about pets now and always: your pets are a part of your family. Treat them that way and we will all be better off.

 

[David Baxter PhD]

COVID and Animals: What YOU Need to Know: Part Two.
Bruce Roney, President & CEO, Ottawa Humane Society
December 3, 2020

Two weeks ago, I shared Dr. Scott Weese’s insights into the research on COVID-19 in dogs and cats. Now I would like to share what you need to know about the virus in other species.

Pigs
SARS-CoV-2 (the virus that causes COVID-19 infection) binds to the surface of cells by way of the ACE2 receptor, which pigs also have and the receptor is similar to humans’ ACE2 receptors. However, various research findings indicate that pigs are either not susceptible to COVID-19 infection or only minimally.

Bottom line: The risks for pigs are low, but not zero.

Cattle
Considering the prevalence of cattle as food animals, it is fortunate that cattle appear to be minimally susceptible to SARS-CoV-2. In fact, one study found that cattle inoculated with the virus displayed some signs of infection, however when placed amongst healthy cattle, there was no evidence that the virus had spread to the other cattle.

Bottom Line: Cattle are minimally susceptible at most.

Horses
There is very little research examining the relationship between COVID-19 and horses. Studies indicate that potential for infection in horses is possible, however much more research is needed to establish a clear link of infection between horses and humans.

Bottom line: We don’t know yet.

Birds
Some viruses may infect both mammals and birds, however oftentimes they do not affect both. Fortunately, birds do not seem to be susceptible at all to SARS-CoV-2. This prediction has been corroborated by studies examining chickens, ducks, as well as turkeys, quail, and geese.

Bottom Line: Birds are not susceptible.

Mink
Mink are very susceptible to the SARS-CoV-2 virus. This became extremely problematic as mink farms are very common in Europe and led to widespread infection as a result of human-to-mink infections; which subsequently enabled extensive infection between mink. To curb the infections, millions of mink on these farms have been culled. At present, Canada has approximately 70 mink farms, which contain a fraction of the 17 million mink in Denmark. No cases have been found in Canadian mink to date.

Bottom line: Mink are very susceptible and this has been devastating to mink in Europe, though not (yet) in Canada.

Marine Mammals
There is limited research examining the relationship between COVID-19 and marine mammals. Sewage is often the most common route of passing pathogens to marine life; and, the virus is known to survive for a short period of time in sewage. By examining species’ receptors, two studies identified various whales and porpoises as potentially highly susceptible to infection. One study ranked various marine mammals’ susceptibility to infection and alarmingly found that some of the most endangered marine species are potentially more susceptible to infection than humans.

Bottom line: The risk of transmission to humans is negligible. Humans might transmit the virus to marine mammals, and some of the most endangered species may be the most at risk for infection.

Dr. Scott Weese is the former Canada Research Chair in Zoonotic Diseases at the University of Guelph and a veterinary internal-medicine specialist and chief of infection control at the Ontario Veterinary College. He writes an outstanding blog, called Worms and Germs that I follow regularly. He is a great friend of the Ottawa Humane Society and has always made himself available for any information we need.