STARKVILLE, Miss. (WJTV) – Chronic wasting disease (CWD) has entered the Mississippi white-tailed deer population, and hunters play a big part in controlling the disease.
The disease is easily transmissible to deer through saliva, feces, urine or a contaminated environment. According to the Mississippi State University (MSU) Extension Service, conditions are ripe for CWD’s spread when an infected deer congregates with other deer in a small area, such as around a salt lick or feeder.
Bronson Strickland, wildlife specialist with the MSU Extension Service, said CWD’s almost permanent effects make it dangerously different than other diseases.
“Hemorrhagic disease is viral and common among the deer population, but while it can be catastrophic in certain locations and years, that disease cycle has an endpoint,” Strickland said. “This does not happen with CWD.”
CWD lingers, both in terms of how slowly the disease kills individual deer and how slowly the disease spreads through a population.
“More importantly, there is no annual end point, such as the arrival of cold weather,” Strickland said. “Once the disease becomes entrenched in a population, it is very difficult, if not impossible, to do anything about it.”
William McKinley, deer program coordinator with the Mississippi Department of Wildlife, Fisheries and Parks (MDWFP), said the disease is similar to Creutzfeldt-Jakob disease and Bovine Spongiform Encephalopathy, or mad cow disease. Unlike mad cow disease, which transmits to humans at a very low rate, CWD has never been known to transmit to humans.
“CWD infects white-tailed deer in Mississippi, and elk, reindeer, moose and red deer in other areas,” McKinley said. “It’s been found in 26 states and three Canadian provinces, as well as in four other countries.”
CWD was first identified in 1967 in a captive mule deer in Fort Collins, Colorado. There is speculation CWD may have mutated from scrapie, a disease similar to CWD that infects sheep. In CWD’s 16- to 20-month incubation period, infected animal shows no signs of disease.
“When the animal becomes clinical, they begin to stumble, are listless, lose weight and forget common things,” McKinley said. “It is comparable to a sped-up version of dementia in humans.”
Physically, the disease causes holes to form in the brain, and when a hole is formed in a region that controls a function critical to life, the animal dies.
“Animals typically die within 6-8 weeks of showing symptoms,” McKinley said. “They spread the disease even when they show no symptoms.”
There have been 83 positive deer reported in the state in eight counties in Mississippi: Issaquena (2), Pontotoc (1), Marshall (20), Benton (56), Panola (1), Tallahatchie (1), Tippah (1) and Alcorn (1).
Strickland said every hunter in Mississippi and surrounding states has two good reasons for sampling the deer they harvest.
“Our state wildlife agencies can’t manage the disease to keep it from spreading if they don’t know where it is, and if you eat your venison, testing it first gives you peace of mind,” Strickland said.
He said the Centers for Disease Control and Prevention report that there have been no reported cases of CWD infection in people, but some animal studies raise concerns that there may be a risk to humans.
To keep CWD numbers in check, wildlife specialists have determined that the best management practices are to lower deer density and eliminate practices that encourage deer to congregate.
Wildlife specialists are confident that Mississippi hunters can learn to manage the deer herd in the state to keep CWD from reaching high levels.
Hunters are encouraged to bring the heads of all deer harvested for free testing at one of 46 drop-off sites across the state. Store the meat in coolers before processing until CWD test results are back, a process that usually takes about a week.
“Many areas of the state are not well sampled, so we cannot rule CWD out in those areas,” McKinley said. “We have many counties that have only turned in six or eight deer over an entire season, so we don’t know if CWD is in that area or not.”
When handling deer, such as when field dressing a harvested animal, wear latex gloves and minimize contact with the nervous system — the brain and spinal column.