A deer farmer's counterpoint commentary ("Deer farms are the remedy, not the disease," Sept. 8), in response to "Minnesota's wild deer are being threatened by 'farms' " (Aug. 27), which blamed deer farms for the rising incidence of chronic wasting disease (CWD) in the wild deer population, needs some clarification.
Many experts contend that chronic wasting disease was initially spread from captive deer in Colorado, some transported to other states. Exacerbating the spread of this disease have been state wildlife management practices that foster large deer numbers for hunters and elimination of population-controlling wolves.
The whitetail deer population is now estimated at some 30 million across the U.S. and is also impacting forest regeneration.
Now, in the midst of the COVID-19 pandemic, we face another issue involving deer. A recent study of the incidence of SARS-CoV-2 in whitetail deer by the USDA's Animal and Plant Health Inspection Service discovered that 33% of 481 blood samples collected from January 2020 through March 2021 from deer populations in Illinois, Michigan, Pennsylvania and New York tested positive for this coronavirus. In another study, samples taken early this year from eight whitetail deer in Ohio contained SARS-CoV-2.
How the deer became infected is not known, but among the possibilities is close contact with COVID-19 diseased people on deer farms and in parks, and perhaps picnic leftovers and human feces in public parks and campgrounds.
Whitetail deer can be infected by and transmit SARS-CoV-2 to other deer through nasal secretions and fecal matter, researchers reported in the Journal of Virology. Fawns in the small study did not develop clinical signs of illness, but the virus replicated and was shed, suggesting deer are potential viral reservoirs.
Since captive mink are highly susceptible to this virus and have been infected by caretakers with COVID-19 — and, in turn, have infected workers — there is also concern that infected deer could pass this coronavirus to wild mink and other wildlife.
Deer farmers must therefore take precautions to stop infected staff from passing this disease to deer, not only in Minnesota but in all states where deer are held in captivity. Zoos are now taking such precautions.
As for CWD control, the whitetail deer population needs to be significantly reduced in most states. Encouraging wolf numbers under Endangered Species Act protection to prohibit trapping, snaring and shooting would be prudent. Livestock keepers practicing nonlethal methods of wolf deterrence, especially with guard dogs, should be compensated for confirmed losses to wolves and not to disease or exposure and neglect.
These are the kinds of holistic "One Health" issues that state and federal animal and public health agencies are beginning to acknowledge. They lead to questioning the commercial farming of wild animals as well as the "wet markets" in China and elsewhere — along with wildlife management practices that are more profit-driven than science-based and ecologically sustainable, especially killing wolves and predators to increase deer numbers for the hunting industry.
Michael W. Fox, of Golden Valley, is a veterinarian.