CWD is a 100% fatal disease that infects members of the deer family, including elk, moose, mule and white-tailed deer.
CWD is not a virus, bacteria, or fungus. It is caused by infectious, mis-folded proteins, called prions, that spread throughout the animal and result in organ damage and eventual death.
These prions are found throughout bodily tissues and secretions and are shed into the environment before and after death. When other animals come in contact with the prions, either from infected animals or from contaminated environments, they can be infected. CWD does not appear to naturally infect cattle or other domesticated animals.
The disease is slow acting, degenerative, and always fatal.
The name comes from the appearance of symptomatic animals, which get very skinny and sick-looking before they die. There is no vaccine or cure for CWD.
There is no known transmission of CWD to humans. However, The Centers for Disease Control and Prevention (CDC) recommends that hunters harvesting a deer, elk, or moose from an area where CWD is known to be present have their animal tested for CWD prior to consuming the meat, and to not consume the meat if the animal tests positive.
Some simple precautions should be taken when field dressing harvested animals:
To guard against importing CWD from other states, Montana regulates the transportation of hunter-harvested deer, elk, and moose from CWD-infected states. It is illegal to bring into Montana the carcass of any deer, elk, or moose from the states and Canadian provinces where CWD has been detected.
As of 2020, those states and provinces were Arkansas, Colorado, Illinois, Iowa, Kansas, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Mexico, New York, North Dakota, Ohio, Oklahoma, Pennsylvania, South Dakota, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, Wyoming, and the Canadian provinces of Alberta, Quebec, and Saskatchewan.
What hunters are allowed to bring home:
Hunters should consult with meat processors or taxidermists for any specific requirements they may have. Please read the recommendations below if you intend to donate your deer, elk or moose to a food bank.
Montana Fish, Wildlife & Parks is urging hunters to have their deer, elk and moose tested and have a negative test result in hand prior to donating no matter where in Montana these animals are harvested. The funding for much of this donated meat comes from hunters through a program called Hunters Against Hunger. Hunters are asked to donate to the program when they purchase their license each year. The donations go to offset the cost of processing the wild game. Donations to Hunters Against Hunger and other donation options are welcome anytime and can be done online at fwp.mt.gov or at any license provider.
The origin of CWD is unknown. It was discovered in 1967 in mule deer at a research facility in Colorado. Shortly thereafter it was also found in captive mule deer and elk in Ontario, Colorado and Wyoming. By the 1990s, it was discovered in wild white-tailed and mule deer, elk and moose in Colorado and Wyoming and among captive animals in Saskatchewan, South Dakota, Montana and Oklahoma. As of 2020, it has been found in captive or free-ranging herds in 26 states, three Canadian provinces, Norway, Sweden, Finland and South Korea.
CWD was found among wild deer in Montana in 2017. CWD infections along our northern and southern borders are likely the result of the natural spread of the disease from Alberta, Saskatchewan, and Wyoming to Montana. Alberta, Saskatchewan, and Wyoming have documented CWD-positive deer close to Montana’s border. CWD is also found in neighboring North and South Dakota.
After decades of CWD management across the country, most agencies and researchers agree that CWD cannot be eradicated once it infects a herd. Other states have attempted eradication and set up unreasonable expectations with hunters and the public. Eradication is not the goal of FWP.
Scientists believe CWD prions likely spread between animals through body fluids like feces, saliva, blood, or urine, either through direct contact or indirectly through environmental contamination of soil, food or water. Once introduced into an area, the CWD protein is contagious within deer and elk populations and can spread quickly. Experts believe CWD prions can remain in the environment for a long time, so other animals can contract CWD from the environment even after an infected deer or elk has died. Feeding wildlife such as deer is illegal and can congregate animals and lead to the rapid spread of disease.
If CWD infects enough animals, it could reduce the herd in the long term. Other states have seen deer populations decline when CWD infects 20 to 40 percent of a herd. In Wyoming, heavily infected herds of mule deer declined 21 percent per year and whitetails declined by 10 percent. Colorado saw a 45 percent decline in infected mule deer herds over 20 years.
Because the distribution and intensity of CWD infections are variable across a broad landscape, the impacts across the landscape will also be variable. Keeping deer numbers down and dispersed, and reducing buck:doe ratios, may keep the prevalence low and manageable. Fish, Wildlife & Parks’ focus will be on managing CWD-infected areas for prevalence at 5 percent or lower and preventing spread. This may also mean keeping deer or elk numbers low to keep infection rates low.
CWD was first found in the wild in October 2017. To date, CWD has been detected in Big Horn, Blaine, Carbon, Daniels, Gallatin, Hill, Liberty, Lincoln, Madison, McCone, Phillips, Powder River, Prairie, Rosebud, Sheridan, Treasure, Valley, Yellowstone counties.
Read FWP's Management Plan to learn how Montana is addressing the problem. In 2020, Montana Fish, Wildlife & Parks will continue chronic wasting disease surveillance in high-priority areas known as Priority Surveillance Areas in northwest, southwest and eastern Montana. Hunters who harvest a deer, elk or moose in these areas are asked to voluntarily submit their animal for sampling to help gather additional data for that area. This information will be used to help inform the best management strategies for the affected hunting districts.
FWP is asking hunters to properly dispose of their carcass waste in a landfill to help prevent the spread of the disease. FWP has also begun to liberalize harvest (by either increasing total tags or either sex/antlered tags) in certain CWD positive hunting districts, with the goal of reducing herd densities and mule deer buck densities. Mule deer bucks are more likely to be CWD positive than does. FWP is currently working on a CWD and urban deer management plan for the town of Libby.
Hunting is the primary tool for monitoring and managing the spread of CWD. Concerns over CWD shouldn’t stop you from enjoying hunting season. Hunters are critical to conservation efforts across the state and protecting our wildlife heritage.
Proper carcass disposal is critical to protecting our herds. All carcass parts, such as brain, eyes, spleen, lymph glands, and spinal cord material, should be bagged and disposed of in a landfill or may be left at the kill site. Dumping carcasses is illegal, unethical and can spread diseases, including chronic wasting disease. This new requirement applies to all deer, elk, and moose carcasses wherever in the state they are harvested by hunters or as vehicle-killed salvage.
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