Coronavirus in White-Tailed Deer

Scientists keep learning more about the various animal species that are at risk for getting COVID. High numbers of white-tailed deer have contracted SARS-CoV-2 coronavirus across the United States. The large population and social behavior of the deer, along with their close proximity to humans, appear to be the main causes for this.

So far, the deer populations have not been impacted by the infection. However, they could be a reservoir and pass it to other animals. This makes eradicating Covid-19 very difficult. and, although domestic livestock appears unaffected by SARS-CoV-2, white-tailed deer could pass the virus onto our farms and back into the human population.


Do White-tailed Deer Get Coronavirus?

Yes, white-tailed deer do get coronavirus. It was discovered quite by accident when scientists were conducting research into chronic wasting disease on dead deer.

Virologist Suresh Kuchipudi and infectious disease specialist, Vivek Kapur, both from Penn State University, mapped occurrences of SARS-CoV-2 coronavirus in the deer (2). They were shocked to discover that the virus was abundant in the population. Approximately 60% of the samples they analyzed tested positive for the virus.

A follow-up study revealed that up to 80% of the population had this type of coronavirus. Due to these high numbers, researchers are sure that the deer are transmitting the virus to one another.

To learn more about the species Read my article Everything You Want To Know About White Tailed Deer to answer all your questions.


How Do Deer Spread Coronavirus To Each Other?

Deer are social animals. Bucks can live in bachelor groups of up to six and does live in large multigenerational herds.

With 25-30 million white-tailed deer across the U.S., their numbers are thriving (1). Living in close proximity means any potential disease outbreaks could spread rapidly through the population.

 

Can Deer Spread Coronavirus To Humans?

It is unlikely that a human will contract coronavirus from a wild deer. It is thought that white-tailed deer caught coronavirus from humans but experts don’t believe it can be passed back to people that easily.

This may be, in part, due to the little contact we have with wild deer.

It seems that it is easier for deer to pick up the virus indirectly from humans. This could be via discarded trash (including used face masks), feeding deer in your backyard, or as simple as throwing an apple core from your car window. It has also been suggested that waste water, containing SARS-CoV-2, could be finding its way into the animals’ drinking water (4).

It only requires a few deer to contract the virus and it will spread very quickly among the population as they are such social animals.

However, transmission from deer to humans is less likely as we don’t tend to touch the vegetation chewed by deer or be close enough to breathe the same air.

Coronaviruses can spread readily between species and are even considered zoonotic, meaning they can transfer to people (3). Danish officials culled their entire population of farmed mink when a mutated strain of coronavirus spread from the mink to humans.

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Are Deer A Reservoir For Coronavirus?

There is a concern that wild deer populations may be acting as coronavirus reservoirs. This could make controlling the virus or eradicating it very difficult.

The longer it remains within the deer population, the more likely it will mutate. Mutated strains of SARS-CoV-2 could pose serious problems for people should it somehow transfer back to us.

However, as of yet, deer don’t seem to pose a threat. Bryan Richards, a wildlife biologist, said that only one case of coronavirus has been reported by a hunter who came into contact with a deer (4).

It is not certain the deer transmitted the virus but if so, this was a single case among millions of hunts taking place across North America at the time.

 

Is coronavirus affecting the deer population?

No, deer are still thriving across America. So far there doesn’t appear to be any effect on the deer population. Scientists are watching the white-tailed deer carefully and have not reported any significant changes.

 

Do deer with coronavirus look sick?

Again, the answer appears to be ‘no’, Although some coronaviruses cause diarrhea in young ruminants, like deer, this does not seem to be the case with SARS-CoV-2. The U.S. Department of Agriculture even experimentally infected some captive deer with the virus and observed no outward physical change in the animals.

Chronic Wasting Disease is a very different disease caused by abnormal pathogens. CWD does cause extreme physical body changes and starvation.

 

Can white-tailed deer spread coronavirus to my livestock?

It is very possible that white-tailed deer can spread coronavirus to livestock, however, current evidence suggests many livestock species are not susceptible to it.

There are already specific bovine coronaviruses that populate wild and domestic ruminants (5). Bovine-coronavirus is very common in cattle worldwide. It infects up to 90% of the global cattle population without any clinical signs (6).

However, it can be particularly dangerous in young calves where it causes severe diarrhea and mortality (3). In adult cattle, it can reduce productivity (such as milk and meat) and subsequently inflict economic losses.

A number of domestic species have been studied in order to determine their response to SARS-CoV-2 infection. Sheep, goats, alpacas, rabbits, and horses were inoculated with the virus but showed no clinical signs of infection and were unlikely to be able to transmit the virus to others (7).

 

References:

1. USDA Wildlife Services, Living with Wildlife – Deer https://www.aphis.usda.gov/wildlife_damage/nwrc/publications/living/deer.pdf

2. Kuchipudi, S. V., Surendran-Nair, M., Ruden, R. M., Yon, M., Nissly, R. H., Vandegrift, K. J., ... & Kapur, V. (2022). Multiple spillovers from humans and onward transmission of SARS-CoV-2 in white-tailed deer. Proceedings of the National Academy of Sciences119(6), e2121644119.

3. Vlasova, A. N., & Saif, L. J. (2021). Bovine coronavirus and the associated diseases. Frontiers in Veterinary Science8, 643220.

4. Mallapaty, S., Nature (2022) COVID is spreading in deer. What does that mean for the pandemic?

5. Saif, L. J., & Jung, K. (2020). Comparative pathogenesis of bovine and porcine respiratory coronaviruses in the animal host species and SARS-CoV-2 in humans. Journal of Clinical Microbiology58(8), e01355-20.

6. Ulrich, L., Wernike, K., Hoffmann, D., Mettenleiter, T. C., & Beer, M. (2020). Experimental infection of cattle with SARS-CoV-2. Emerging infectious diseases26(12), 2979.

7. Bosco-Lauth, A. M., Walker, A., Guilbert, L., Porter, S., Hartwig, A., McVicker, E., ... & Bowen, R. A. (2021). Susceptibility of livestock to SARS-CoV-2 infection. Emerging Microbes & Infections10(1), 2199-2201.



Author, Ame Vanorio is the founder of Fox Run EEC and an environmental science teacher.