Virus that causes COVID-19 found in Quebec deer

The virus that causes COVID-19 has for the first time been found in wildlife in Canada.

SARS-CoV-2 was found in three white-tailed deer after samples were taken between Nov. 6 and Nov. 8 in the Eastern Townships region in Quebec, Environment and Climate Change Canada said in a news release on Wednesday.

The deer appeared to be healthy and showed no signs of the disease, the agency said. The deer may be able to carry the virus without showing symptoms, much like how some humans can carry the virus and remain asymptomatic. 

This is the first time the virus has been found in wild animals in Canada, though globally it has already infected various species that are domesticated or kept in captivity, including farmed mink, cats and dogs, and animals in zoos such as tigers, gorillas, cougars and otters. 

The virus has already been detected in deer in the United States, and a study published earlier this month showed SARS-CoV-2 antibodies in 40 per cent of blood samples collected from deer in Illinois, Michigan, New York and Pennsylvania in 2021.

The significance of this discovery comes down to how the virus behaves.

"We kind of assumed there was a good chance it was going to be present in deer in Canada, but we really didn't know," said Scott Weese, an infectious disease veterinarian from the Ontario Veterinary College at the University of Guelph.

Weese said it's one thing if SARS-CoV-2 spreads among a few deer and eventually dies off after a few weeks.

But another, more concerning scenario, is that it could continue to spread to other deer and other species, becoming a possible source of infection for humans, and a source of more variants. 

"That's what we're worried about, because if that's the situation then you can have this animal reservoir that we can get exposed to regardless of what's going on with regards to control in people," Weese said. 

"Ultimately we just want this to be a human infection, because if it's just a human infection all we need to do is control it in people, which obviously isn't easy — but it's easier to control it in one species than many species."

He said if the virus has been found in three deer in Quebec, that's probably just the tip of the iceberg and there are likely many more infected deer in the population. 

Weese said it's another reminder for people to keep wildlife wild, and keep their distance from deer. 

Hunters should also take note that, as an added precaution, Environment and Climate Change Canada is warning people to wear a mask if they handle respiratory tissues and fluids from deer, and avoid splashing and spraying any fluids from those tissues.