COMMENTARY BY DR. DAVE SAMUEL
Deer probably do not have COVID-19. TV and radio news reported that deer tested positive for COVID, but here is what that really means.
The U.S. Department of Agriculture previously infected deer in captivity with COVID. This showed that they could get the virus. In the latest study, they analyzed blood samples from wild deer looking for antibodies for SARS-CoV-2. SARS-CoV-2 is the coronavirus that causes COVID-19.
There were 481 samples taken in 2020 to early 2021 from New York, Pennsylvania, Michigan and Illinois. A total of 33% had antibodies for COVID. This doesn’t mean they got sick from COVID. They just had the antibodies for COVID and were exposed to the virus.
What is the difference between exposure and infection? An animal has been exposed to or infected with the virus when you find antibodies in its blood. The antibodies are the body’s way of developing an immune response to infection.
If a deer has antibodies to COVID, that doesn’t mean it has the disease. It means that somehow that deer was exposed to COVID. It could have the disease, but the serum blood tests was just to detect antibodies.
There is a test that would confirm the deer has the virus in its body, but those have not been done yet.
Nearby Pennsylvania showed that 31% of 199 samples had antibodies. Interestingly the researchers had serum from 143 deer taken before January 2020 (before the pandemic) and only one deer had antibodies. In fact that sample was so low they believe it was a false positive.
These positive COVID deer samples lead to a ton of questions. How did these 131 deer come into contact with the virus? No one really knows. They could have gotten it from other animal species, or from humans (who must not have been wearing their masks….ha, ha), or from other deer, or from the environment (i.e. bait stations).
Another obvious question. Can deer spread the virus to humans? To date there is no evidence that we get the virus from any animals and not from deer. Another question. Are deer able to shed live virus? We don’t know but it seems doubtful.
Do deer with antibodies show any clinical signs that they’ve had or do have the virus? Again the answer is no. And in another study where deer were infected with coronavirus in captivity, none showed any signs of infection. If they were sick, they didn’t show it and no tests showed anything going on. They just developed antibodies. Note that lots of animals including your pets, have antibodies for various diseases. Some wild animals have antibodies for anthrax, rabies, avian influenza and many other diseases. That’s why I have always suggested that deer hunters wear rubber gloves when they gut a deer. Why take a chance?
The Department of Agriculture plans to do more studies on the significance of finding COVID antibodies in deer. Will deer that came into contact with the virus impact deer around them of deer populations? My guess is that they won’t have any impact on other deer or people, but we don’t have data to prove this one way or another.
Is eating deer meat from deer that have COVID antibodies a problem? There is no evidence here either and my guess is that future research will find no such evidence. However, hunters always need to practice good hygiene when processing and cooking venison. This finding of COVID antibodies doesn’t change that. It just reinforces what hunters have always known.
So now we know that deer have been exposed to the virus and their immune system responded by forming antibodies. We don’t know where deer got it. I might add that many humans have this virus in their body. I know I do and I have no idea where I got it.
If you are older and in the high risk category for COVID, and you harvest a deer, you might want to get others to gut and butcher your deer just to be safe. There is a lot more to learn about COVID in deer, but for now we need to just be cautious and move on.
