With COVID-19 now detected in Ontario deer, wildlife experts seek to fill research gap

A Guelph expert says crucial research is underway after five white-tailed deer in southwestern Ontario tested positive for COVID-19.

Provincial ministry says the animals, tested in November, were located in the London area

Five white-tailed deer in southwestern Ontario tested positive for COVID-19 and researchers are now trying to learn more about what this could mean for other species and humans as well. (Paul Chiasson/The Canadian Press)

A Guelph expert says crucial research is underway after the discovery of five white-tailed deer in southwestern Ontario that tested positive for COVID-19.

The Ontario Ministry of Northern Development, Mine, Natural Resources and Forestry confirmed these are the first cases reported in free-ranging wildlife in Ontario.

Cases in wildlife have been detected in deer in Quebec and Saskatchewan, as well as northeastern U.S.

Scott Weese, chief of infection control at the Ontario Veterinary College at the University of Guelph, said it's still not known how the deer contracted COVID-19 and more research is needed to determine the possibility of transmission from deer to other species.

"This is a human driven pandemic and we spill it over into animals probably not uncommonly, but we don't really know how it got into deer," Weese told CBC K-W.

"The other potential is the animal bridge: cats are quite susceptible to this virus. If you have a person that has a cat and the cat goes outside, could the cat be a bridge?" he added.

Transmission path

He said if deer can transmit the virus to other animals or among themselves, then it can be challenging to control the spread and could potentially create a reservoir of the virus.

He said the bigger concern is that transmission could lead to high replication and mutation rates that could cause issues if they spread back into people.

"If were starting to find old strains in deer or different strains [of COVID-19] in deer, then we'd be more concerned that this virus is hanging out for a while and changing," he said.

"If we're finding the same stuff we're finding in people then it would support the fact that this is just [a case of:] 'humans infect deer and it burns out'. But we need more time to sort that out."

The ministry said the samples were collected in November from the London area. To date, 213 samples were collected in 2021 and have been tested, with testing initiatives ongoing.

Dr. Scott Weese is the Ontario Veterinary College’s chief of infection control. (Dave MacIntosh/CBC)

Rate of infection

Based on current information, the risk of wildlife — including deer — spreading the virus to people is low. There has been no known transmission of COVID-19 from deer to humans at this time, the ministry said.

More research needs to be done to better understand the range of species that are susceptible and how species may be infected, carry and transmit the virus.

There is currently limited information on animals and COVID-19 and whether they can spread the virus. Usually it's spread from human to animal, or exposure from the environment.

So far, there has been reported transmission from animal to humans from farmed mink in Europe, according to research though the World Organization for Animal Health.

Studies in the U.S. have found evidence of widespread transmission in some areas where white-tailed deer are infected, which could suggest transmission from human-to-deer and deer-to-deer.

Hunting, using game meat

The Canadian Wildlife Health Cooperative suggests there have been no reports of people contracting COVID by preparing or eating meat from an animal infected with the virus.

Weese said he's not worried about venison being a source of infection as long as people continue to handle and cook the meat properly.

Until more research can be done, people who hunt are urged to wear masks when exposed to animals' respiratory tissues and fluids, which should not be splashed or sprayed.

Proper hand and eye protection should be worn when handling and dressing the carcass.

These precautions are especially important for people who aren't fully vaccinated or are at higher risk of COVID-19 illness. Whenever possible, people who are fully vaccinated should handle and dress carcasses.

"There is currently no evidence that humans can get COVID-19 from skinning, processing, or eating meat from wildlife, however hunters and trappers should always follow food safety recommendations, such as practicing good hygiene and properly cooking meat to an internal temperature of 74°C (165°F) to kill any parasites, viruses or bacteria that may be present," the ministry said in an email.

People who are symptomatic are advised to avoid close contact with animals.