Chronic Wasting Disease (CWD)
- Why care about CWD?
- CWD is very difficult to manage once it is found on the landscape.
- There are no known vaccines or cures for any prion diseases, including CWD.
- The prions can remain in the environment for years or even decades, and are extremely difficult to destroy.
- Studies indicate that CWD can lead to long-term declines in deer populations.
- The risk to human health is not zero. Recent studies have indicated that CWD is transmissible to species of primates that are genetically similar to humans.
- If CWD spreads into the Ceded Territories, this would threaten a significant source of traditional food for tribal communities.
- What can hunters do about CWD?
Report sick deer
If you observe and/or shoot a deer that appears to be sick, immediately report the deer to the nearest tribal registration clerk, GLIFWC biologist, conservation warden, or your local state DNR biologist. Avoid handling or consuming any deer that looks sick.
Get your deer tested
If you would like to get your deer tested for CWD, please contact your local tribal registration station, GLIFWC biologist, or state DNR office. When preparing the deer head for testing, it is important to leave 4 - 6 inches of the neck attached to the head. Preliminary test results are typically available within two weeks. A map of Wisconsin CWD sample collection sites can be accessed here.
Prevent the spread!
Proper disposal is key to preventing the spread. Regardless of where the deer was harvested, all carcass parts and waste should be bagged, sealed, and brought to the local landfill if possible. One of the worst things you can do is to transport a whole deer carcass far from the point of kill and dump the carcass remains in your back yard or elsewhere in the environment. If your landfill will not accept carcass waste, bury the remains deep enough to prevent scavengers from digging them up. Tribal communities are considering adopting carcass transport regulations to prevent the spread of CWD in the Ceded Territories. Hunters should minimize the transport of whole deer carcasses and consider field dressing and butchering/processing deer as close to the point of kill as possible. A map of facilities accepting deer carcasses in Wisconsin can be accessed here.
What is CWD?
Chronic wasting disease is a fatal, contagious, neurodegenerative disease that affects members of the deer family. CWD is caused by a mutated protein called a prion (pronounced “pree-on”) and belongs in a group of diseases known as transmissible spongiform encephalopathies (TSEs). TSEs are similar to bovine spongiform encephalopathy (BSE; aka mad cow disease). Eventually, the infected deer undergoes spongy degeneration of the brain and other nervous tissue. To date, CWD has been found in 24 states and 2 Canadian provinces.
How does CWD affect deer?
A deer infected with CWD may not show any symptoms for several years, but eventually CWD causes deterioration of the brain and nervous tissue, resulting in emaciation, excessive drooling, abnormal behavior, loss of bodily functions, and eventually death.
Can CWD be treated?
No. There are no known treatments and all infected deer will eventually die from the disease unless they die by other means first (e.g., automobile collision, harvest, predation, etc.). CWD prions are extremely resistant to normal methods of disinfection and are very difficult to destroy once in the environment.
Does CWD only infect white-tailed deer?
No. Besides white-tailed deer, CWD has been found in free ranging populations of mule deer, moose, reindeer, and elk.
How does CWD spread?
CWD can be transmitted from deer-to-deer through contact with saliva, blood, urine, and feces. Prions can also persist in the environment from the natural decomposition of CWD-infected deer carcasses. The prions can bind to the soil and other forms of particulate matter and can remain viable in the environment for years or even decades. Human activity has likely been the primary cause of the spread of CWD. Humans contribute to the spread of CWD by transporting CWD-infected animals from one place to another. This includes the transport of deer or deer parts that are harvested during the hunting season and the sale of live deer, deer parts, and deer products (e.g., urine, antlers) by the captive deer farm industry. In fact, hunters are encouraged to avoid using urine, attractants, and antlers sourced from captive deer farms because of inconsistencies in the regulation and oversight of these products.
Is CWD infected deer meat safe to eat?
The risk to humans is not zero. Other prion diseases have made the jump to humans, causing symptoms similar to dementia. We do not yet have a full understanding of the long-term effects that exposure and/or consumption might have on humans. Currently health officials recommend against handling or consuming any meat from animals that could be infected with CWD. So far, there have been no verified cases of humans becoming infected with CWD. Recent research suggests that close relatives of humans (i.e., macaques) can become infected with CWD.
- Safe Handling and Disposal Recommendations
- Always wear latex/rubber gloves when field dressing and butchering your deer
- Use knives/tools that are dedicated to butchering/processing your deer – do not use knives that you normally use in your kitchen
- Use a disposable cutting surface such as clean plywood or paneling
- Avoid sawing or cutting through any bones, the spinal column, the eyes, spleen, or lymph nodes (see image below)
- Trim meat a considerable distance away from any shattered or broken bone
- Completely bone-out all of the meat and remove excess fat and connective tissue
- Seal all disposable materials and equipment used for processing your deer in plastic trash bags and dispose of in a landfill when possible. You can also bury the remains, as long as it is deep enough to prevent scavengers from digging them up.
- Process individual deer separately and carefully label meat from any deer you are getting tested
- An informative video series which illustrates how to safely handle, field dress, and bone out a deer can be found here.
- Tribal CWD Management Areas
At the September 6, 2018 meeting, the Voigt Intertribal Task Force passed a motion supporting recommendations from the Intertribal CWD Working Group. The Intertribal CWD Working Group was established by the VITF in 2016 and consists of VITF representatives and wildlife biologists from tribal natural resources departments in Minnesota, Wisconsin, and Michigan. The recommendations approved of by the VITF include the establishment of a tribal CWD management area (see map) and regulations concerning the transport, disposal, and registration of deer harvested within the tribal CWD management area.
Tribal Disease and Invasive Species Management Areas
Map - Tribally Designated CWD Management Area
CWD detections in Minnesota, Wisconsin, and Michigan
* Count of occurrences is only available for Wisconsin and not available for Michigan or Minnesota.