Chronic Wasting Disease is disorder of the neurological system that affects cervids, animals that are members of the deer family, such as deer, elk, and moose. CWD is caused by a prion, or misfolded protein. Prions are mostly found in the brain. Cervids that contract CWD may take months or even years before they show symptoms of having the disease. Symptoms can include extreme weight loss, lack of coordination, drooping head and/or ears, excessive drooling, excessive drinking, and excessive urination. CWD is always fatal to infected cervids.
CWD spreads by both direct contact between animals and indirect contact of saliva, urine, feces, blood, carcass parts of an infected animal and contaminated soil or plants. Once the prions are on the landscape, they can stay infectious for years. Unlike viruses, bacteria or fungus, there is no antidote or cure for a prion disease; prions are resistant to denaturation by chemical agents, such as disinfectants, or physical agents, such as incineration.
The disease is not known to affect humans, although the Centers for Disease Control and World Health Organization both recommend not eating infected cervid meat. Beyond the potential human health risks, CWD poses a threat to deer population health and management. Hunting of deer is an important wildlife management tool and has substantial direct (licensing) and indirect (travel, gear, venison processing) impacts on Michigan’s economy.
In 2015, Chronic Wasting Disease was first identified in Michigan’s free-ranging deer population. Since then, CWD has been confirmed in free-ranging deer in Clinton, Eaton, Gratiot, Ionia, Ingham, Jackson, Kent, and Montcalm counties. In 2018, a CWD positive deer was found in Dickinson County in the Upper Peninsula. The authority to protect and manage deer and elk in Michigan lies with the Department of Natural Resources (MDNR), whereas the Michigan Natural Resources Commission (MNRC) has the authority to regulate taking of game species. To help manage CWD, both entities are working together to make changes to hunting practices, such as banning baiting of deer and restricting carcass movement to help limit spread of CWD.