What is chronic wasting disease?

Chronic wasting disease has been detected in many Michigan counties. Know the facts so that you can help slow the spread.

Fawn with chronic wasting disease
Photo by Katie Ockert, MSU Extension

Even if you are not a deer hunter in Michigan, you have probably heard about chronic wasting disease. As with any animal disease, myths, incorrect facts and fear fill the conversations about “zombie deer.”

Chronic wasting disease is disorder of the neurological system that affects cervids, which are animals that are members of the deer family, such as deer, elk and moose. Chronic wasting disease is caused by a prion, or misfolded protein. Prions are mostly found in the brain. Cervids that contract chronic wasting disease 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 ears, excessive drooling, excessive drinking and excessive urination. Chronic wasting disease is always fatal to infected cervids.


Chronic wasting disease 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 (CDC) and World Health Organization (WHO) both recommend not eating infected cervid meat. Beyond the potential human health risks, chronic wasting disease 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, chronic wasting disease has been confirmed in free-ranging deer in Clinton, Eaton, Gratiot, Ionia, Ingham, Jackson, Kent and Montcalm counties. In 2018, a chronic wasting disease-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 Michigan Department of Natural Resources (MDNR), whereas the Michigan Natural Resources Commission (MNRC) has the authority to regulate taking of game species. To help manage chronic wasting disease, 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 chronic wasting disease.

Michigan is also home to hundreds of privately owned cervid farms. Chronic wasting disease was detected in a privately owned cervid in Kent County in 2008 and in two captive deer in Mecosta County in 2017. Privately owned cervid farms are subject to stringent testing regulations through MDNR and the Michigan Department of Agriculture and Rural Development (MDARD).

Continuing research is being conducted at several universities across the United States, including Michigan State University, to learn more about prions, how chronic wasting disease is spread, and how to reduce chronic wasting disease spread in the environment.For more information about chronic wasting disease, visit:

Did you find this article useful?