Hunters: Look for signs of illness in deer
Identifying deer with chronic wasting disease is not always possible by visual observation. There are common signs that may indicate a deer is sick, but it may or may not have chronic wasting disease.
Chronic wasting disease (CWD) is a disorder of the neurological system that affects cervids, or animals that are members of the deer family, such as deer, elk, and moose. CWD is caused by a prion, or a misfolded protein. Prions are mostly found in the brain and the spinal cord but have also been detected in saliva, urine, feces, and blood. 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 Prevention and World Health Organization both recommend not eating meat from infected cervids. 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 (e.g., licensing) and indirect (e.g., travel, gear, venison processing) impacts on Michigan’s economy.
Identifying deer with chronic wasting disease is not possible by visual observation alone. For a positive identification, the deer’s lymph nodes must be tested in a lab. Common signs that may indicate a deer is sick include poor body condition (e.g., rib, hip and/or back bones showing) and lack of alertness (e.g., do not react to sounds around them). Deer with CWD may also have lost their fear of humans. However, deer can be in poor body condition but not be sick if they have recently been lactating or are in an environment with limited access to feed. Or deer may be suffering from a different illness.
The Michigan Department of Natural Resources (DNR) has an interactive web tool that uses photos and allows you to test your ability to identify sick deer. While it is best to observe deer over time, that may not be an option for hunters. If possible, observe deer to see whether they put on more weight or remain in poor condition and start exhibiting additional signs of illness.
CWD testing is recommended, but not required. In 2022, deer heads for testing are being requested from Bay, Berrien, Branch, Cass, Genesee, Huron, Isabella, Hillsdale, Kalamazoo, Lapeer, Lenawee, Livingston, Macomb, Midland, Monroe, Muskegon, Oakland, Oceana, Ottawa, Saginaw, Sanilac, St. Clair, St. Joseph, Tuscola, Washtenaw, and Wayne counties, and from the core CWD surveillance area including Dickenson, Menominee, and Delta counties in the Upper Peninsula. Deer heads from these counties can be submitted at any disease sample submission sites.
Deer harvested in Clinton, Dickinson, Ingham, Ionia, Kent and Montcalm counties can be tested for CWD through the DNR from Nov.15-18 only. CWD testing is available outside of these time frames for a fee through the Michigan State University (MSU) Veterinary Diagnostic Lab or the Wisconsin Veterinary Diagnostic Lab.
Michigan State University Extension recognizes that hunters play a very important role in reducing the spread of CWD by human behaviors. Some strategies hunters can use to reduce their risk of spreading CWD are by following proper field dressing procedures and using best practices for carcass handling and disposal. Hunters can also help in disease surveillance by submitting their harvested deer’s lymph nodes for testing if harvesting deer in an area where CWD has been detected. Movement restrictions apply to animals harvested in Montcalm County in its entirety, or Otisco, Orleans, Ronald and North Plains Township in Ionia County and Nelson, Spencer, Courtland, Oakfield, Grattan, and Cannon Townships in Kent County, unless:
- It is deboned meat, quarters or other parts of a cervid that do not have any part of the spinal column or head attached, antlers, antlers attached to a skull cap cleaned of all brain and muscle tissue, hides, upper canine teeth, or a finished taxidermist mount may be moved out of the area,
- The deer carcass is taken directly to a registered processor; and/or
- The intact deer head detached from the carcass is taken directly to a licensed taxidermist.
Although it is highly unlikely that you will see a free ranging deer that has CWD, it is important to know the signs of sick deer. If you do encounter one, contact the Michigan Department of Natural Resources Wildlife Division at 517-284-9453, or the afterhours Report All Poaching (RAP) line that is available 24/7 at 1-800-292-7800. Reports of a sick deer can also be submitted online.
Don’t forget that beginning this year, deer hunters are required to report a successful harvest within 72 hours or before transferring possession of the deer to another person, processor, or taxidermist. Harvest reporting will allow the DNR to obtain real time data on the number of deer harvested which helps the department make decisions about deer herd management, better assess hunter activity, and will help in determining disease prevalence rates, such a s CWD, more accurately. Information that is collected from the harvest survey is not public and would only be utilized when specifically required by law. Hunters can receive technical assistance to report their harvest over the phone by identifying their closest DNR customer service center location and calling the phone number listed for that location.