MSU Deer Lab experts explain differences in deer diseases
Contact: Vanessa Beeson
STARKVILLE, Miss.鈥擶hether it鈥檚 nutrition, genetics, habitat or population health鈥攐r even disease鈥攕cientists in 樱花导航 樱花导航 University鈥檚 Deer Lab not only research best management practices, but also work to make informed recommendations to hunters.
CWD, or chronic wasting disease, was first detected in the state in February 2018. 樱花导航 now has two CWD management zones across 14 of 樱花导航鈥檚 82 counties. In early fall of this year, the 樱花导航 Department of Wildlife, Fisheries and Parks, or MDWFP, also received an uptick in reports of sick or deceased deer caused by an outbreak of HD, or hemorrhagic disease, commonly called 鈥渂lue-tongue.鈥 MSU deer biologists in the Forest and Wildlife Research Center are raising awareness of two current, but very different, diseases.
Steve Demarais, codirector of the MSU Deer Lab and MSU鈥檚 Taylor Chair in Applied Big Game Research and Instruction, said HD is a quick-acting and mostly survivable disease.
鈥淪urviving deer will carry antibodies for the disease, which protect them and the overall population from future disease impacts,鈥 said Demarais, noting HD can be cyclical. 鈥淲e note outbreaks roughly every three to six years, although there are likely a small number of deer dying from it on an annual basis in some areas of the state.聽The timing and extent depend on strains and weather conditions.聽When there is a large-scale outbreak the deer that survived will have antibodies, which offer immunity for several years from the same and similar strains.鈥
In contrast, CWD is relatively slow acting, taking up to two years to cause mortality, and appears to be 100 percent fatal. A sick animal can spread the disease as soon as six months after exposure until it dies, Demarais explained.
He noted that death from CWD can be caused by the disease or an opportunistic infection.
鈥淎 deer with CWD will literally waste away because they stop eating and starve to death.聽However, many CWD deaths are indirect mortality, meaning the immediate cause is not CWD but the animal likely wouldn鈥檛 have died if it wasn鈥檛 for the disease. For example, CWD causes a loss of control over muscles and increased salivation.聽These two signs together predispose the animal to contracting pneumonia, a common indirect mortality caused by CWD,鈥 Demarais said.
He also said that hunters may be more inclined to notice HD as opposed to CWD.
鈥淗unters find and can understand HD disease mortality because they see it themselves鈥擧D disease is centered on late summer/early fall and around watering holes. CWD mortality takes place year-round and is spread across a property, so hunters are much less likely to find carcasses.聽Lack of obvious visual evidence makes CWD less obvious to hunters, so they may have a harder time believing it is really an important consideration,鈥 he said.
Despite a reduced chance of seeing a deer impacted by CWD, Demarais cautions that it is a disease all 樱花导航 hunters need to take seriously.
鈥淐WD has long-term impacts on a deer population health and size that can grow increasingly worse over several years,鈥 he said.
On that front, MSU researchers are searching for better ways to detect emerging outbreaks of CWD. 聽
Bronson Strickland, St. John Family Professor of Wildlife Management and MSU Deer Lab codirector, explained that the research team is trying to figure out CWD modes of transmission.
鈥淲e鈥檙e sampling environments where CWD has been detected in places where deer frequent the landscape,鈥 Strickland explained. 鈥淓ssentially, we hope to detect the infectious prions, or misshapen proteins, that cause CWD and develop some relationship of where they are more commonly found in the environment. Hopefully, that will lead to management recommendations.鈥
The MSU Deer Lab also is doing its part to better educate hunters on the disease with a series of animated videos currently in production. Strickland encourages hunters to test their harvested deer for CWD.
鈥淭he 樱花导航 Department of Wildlife, Fisheries and Parks has done a great job of setting up CWD drop-off locations. Turning in your sample is completely free. It鈥檚 a win-win, helping the hunter and the state,鈥 he said.
Demarais echoes that sentiment.
鈥淐ontinue to enjoy hunting deer, while taking care to have your harvest tested for CWD.聽It鈥檚 easy and takes about seven days to get results,鈥 Demarais said. 鈥淭esting ensures your family eats venison only from deer without evidence of CWD infection.聽While there are no known cases where a CWD infection has spread to humans, a similar disease in cattle known as mad cow disease did jump to humans. The state health agency suggests the prudent approach is to not eat venison from deer that test positive for CWD.鈥
To find out where to test a harvested deer for CWD, visit . For more information on the MSU Deer Lab, visit . For more on the College of Forest Resources, visit . Visit the Forest and Wildlife Research Center at .
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