Similar to Mad Cow Disease, Chronic Wasting Disease affects the nervous system in members of the deer family, including whitetails.
Mutated forms of proteins called prions become infectious and accumulate in the brain, nervous system tissues, and some lymph tissues. Concentrations of these prions in the brain lead to neurological problems and death.
In Mississippi, CWD first appeared in Issaquena County in February 2018. By September 2023, the state recorded 207 positive cases of infected deer in 10 counties. Besides Issaquena, counties with positive cases include Alcorn, Benton, Marshall, Panola, Pontotoc, Tallahatchie, Tippah, Tunica, and Warren with the worst outbreaks in Benton and Marshall counties.
“Every year, we’ve been finding successively more cases,” said William McKinley, the deer program coordinator for the Mississippi Department of Wildlife, Fisheries & Parks. “In 2022, we found 73 positive deer. One in five bucks from Benton County tested positive during the 2022-23 season out of a couple hundred samples.”
Infected animals might seem perfectly healthy. The disease progresses very slowly. It could take months, or even years for infected deer to show symptoms. Eventually, as the disease attacks the central nervous system, deer have difficulty standing and walking. They might drool excessively, drink often, and urinate constantly. They eventually become emaciated.
“Deer do not begin to show symptoms until the late stages of the disease,” McKinley explained. “Then, it wastes away, and death comes quickly. Of our 207 cases to date, only seven deer looked sick. Most looked perfectly healthy at the time of harvest. Nothing has been completely proven to stop CWD from spreading, but we’re trying to slow the spread. When we find positive deer, we establish a CWD management zone in that county and surrounding counties. In the management zone, all feeding of deer is banned, and we have carcass movement restrictions.”
So far, CWD has not been known to pass from deer to humans. However, some other animals, such as pigs, raccoons, and mice among others, can contract the disease. In addition, some animals serve as disease reservoirs and spread the prions. For instance, if scavengers eat sick deer, those animals could shed prions through their feces. Other deer could ingest those prions and become sick.
“It can go into plants,” McKinley warned. “Deer and other animals eat the plants, and it’s taken up through the roots into that animal. The disease shortens the lifespan of deer. It’s fatal in every animal that comes down with the disease.”
The state established stations all over Mississippi where people can bring their deer for testing. Sportsmen who hunt out of state can bring quartered or deboned meat with no high-risk parts back into Mississippi. They can also bring in finished taxidermy products.
“We will be sampling around the state throughout the hunting season,” McKinley said. “We pulled about 8,000 samples during the 2022-23 season. I expect that number to be similar this season. We are also working with taxidermists across the state to collect tissue samples.”
Deer do not begin to show symptoms until the late stages of the disease. Then, it wastes away, and death comes quickly. Of our 207 cases to date, only seven deer looked sick. Most looked perfectly healthy at the time of harvest.
For more information, see www.mdwfp.com/wildlife-hunting/chronic-wasting-disease.
