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 animals that are members of the deer family, called cervids, such as deer, elk and moose. CWD is caused by a prion, or 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 fungi, 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 the World Health Organization both recommend not eating meat from an infected cervid. 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.
Michigan State University (MSU) Extension recognizes the very important role hunters play in controlling the spread of CWD by (1) using proper field dressing procedures, (2) following best practices for carcass handling and disposal, and (3) submitting deer lymph nodes for testing if harvesting deer in a CWD targeted surveillance area.
CWD testing is recommended, but not required. In 2021, deer heads for testing are being requested from Allegan, Barry, Branch, Calhoun, Eaton, Gratiot, southern Isabella, Hillsdale, Jackson, Kalamazoo, Lenawee, Livingston, Macomb, Monroe, Oakland, St. Joseph, Washtenaw and Wayne counties, along with those from the core CWD surveillance area in the Upper Peninsula (portions of Dickinson, Menominee and Delta counties). Deer heads from these counties can be submitted at any open Michigan DNR deer check station from October through January.
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 January 1, 2022 with the Michigan State University Veterinary Diagnostic Lab or the Wisconsin Veterinary Diagnostic Lab.
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
- 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 to the Michigan DNR.