Chronic Wasting Disease
Be informed and help protect Missouri’s white-tailed deer
Infectious diseases such as chronic wasting disease (CWD) threaten Missouri deer, Missouri's nearly 520,000 deer hunters, millions of wildlife watchers, thousands of landowners, 12,000 Missouri jobs, and hundreds of businesses and communities that depend on the $1 billion boost in economic activity related to deer hunting and watching.
The Missouri Department of Conservation continues to work with hunters, landowners, businesses, other agencies, and partner organizations to identify and limit the spread of CWD in Missouri.
All deer hunters, landowners, businesses — including captive deer breeders and big-game hunting preserves — and conservation organizations in Missouri must continue to do their parts in limiting the spread of CWD and other infectious diseases.
Be informed and get involved
MDC has finished its eight public meetings held around the state on Protecting Missouri’s White-tailed Deer. The Department continues to welcome comments on this issue. All comments will be considered as MDC formulates possible regulation changes related to this topic. These regulation changes will be presented to the Missouri Conservation Commission for its consideration in the near future.
Learn more about CWD below and then share your comments on limiting the spread of CWD and other infectious diseases at Protecting Missouri’s White-Tailed Deer below.
CWD kills deer
Chronic wasting disease infects deer and other members of the deer family, called cervids. CWD belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs) which cause degeneration of the brain in cervids. CWD is transmitted through prions, which are abnormal proteins that attack the nervous systems of these species. These prions accumulate in the brain, spinal cord, eyes, spleen, and lymph nodes of infected animals.
CWD is spread both directly from deer to deer and indirectly to deer from infected soil and other surfaces. Animals with signs of CWD show changes in natural behavior and can exhibit extreme weight loss, excessive salivation, stumbling, and tremors. CWD in deer can only be confirmed by laboratory tests of brain stem or lymph tissue from harvested animals.
The disease has no vaccine or cure. CWD is 100-percent fatal. Deer and other cervids can have CWD for several years without showing any symptoms. Once symptoms are visible, infected animals typically die within one or two months.
There is no scientific evidence that white-tailed deer have a genetic immunity to CWD that could be passed on to future generations.
Once well established in an area, CWD is impossible to eradicate. States with CWD must focus on limiting the spread of the disease and preventing its introduction to new areas.
Don’t confuse CWD with HD
A disease people often mistake for CWD is hemorrhagic disease, or HD. This includes both the bluetongue virus and epizootic hemorrhagic disease (EHD) virus. During the summer and fall of 2012, severe drought conditions contributed to a significant increase in cases of HD throughout Missouri. The naturally occurring viruses are spread by a small, biting midge fly during the summer and fall. Disease outbreaks end when cold weather kills the host flies. Deer typically show symptoms within days of being infected, and not all infected deer die from HD.
CWD is in Missouri and 21 other states
CWD was first recognized in 1967 in captive mule deer in Colorado. Since then, CWD has been found in Missouri and 21 other states and several Canadian provinces. These include Colorado, Illinois, Iowa, Kansas, Maryland, Michigan, Minnesota, Montana Nebraska, New Mexico, New York, North Dakota, Oklahoma, Pennsylvania, South Dakota, Texas, Utah, Virginia, West Virginia, Wisconsin, Wyoming, and Alberta and Saskatchewan.
Missouri’s first cases of CWD were detected in 2010 and 2011 in captive deer at private big-game hunting preserves in Linn and Macon counties. A total of 11 cases of CWD have been confirmed in captive deer at these facilities. CWD has since been found in 10 free-ranging deer within two miles of the captive facility in Macon County. In Missouri, CWD has not been detected outside of small area that borders northeastern Linn and northwestern Macon counties.
CWD is a serious problem for all Missourians
Missouri offers some of the best deer hunting in the country, and deer hunting is an important part of many Missourians’ lives and family traditions. Infectious diseases such as CWD could reduce hunting and wildlife-watching opportunities for Missouri’s nearly 520,000 deer hunters and almost two million wildlife watchers.
Deer hunting is an important economic driver in Missouri and gives a $1 billion annual boost to state and local economies. Lower deer numbers from infectious diseases such as CWD could hurt 12,000 Missouri jobs and many businesses that rely on deer hunting as a significant source of revenue, such as meat processors, taxidermists, hotels, restaurants, sporting goods stores, and others.
CWD also threatens the investments of thousands of private landowners who manage their land for deer and deer hunting, and who rely on deer and deer hunting to maintain property values.
MDC is leading detection and containment efforts
Missourians care about conservation and have given the Missouri Department of Conservation constitutional responsibility to protect and manage all of the state’s wildlife, including white-tailed deer. Both captive and free-ranging white-tailed deer in Missouri are wildlife.
MDC began testing free-ranging white-tailed deer for CWD throughout the state in 2001 when the disease began emerging as a serious issue in the Midwest. To date, MDC has tested more than 41,000 free-ranging white-tailed deer. As a result of that testing, MDC determined that it is highly unlikely CWD has been in Missouri before its recent discovery in Linn and Macon counties.
Since CWD was first found in Missouri in 2010, the Department has intensified efforts to work with hunters, landowners, taxidermists, and meat processors to test free-ranging deer around the state for CWD, especially in the area of north-central Missouri where CWD has been found. This area includes a CWD Containment Zone consisting of six counties: Chariton, Randolph, Macon, Linn, Sullivan and Adair.
MDC has also been working with area landowners and hunters to limit the spread of CWD. Efforts include reducing deer numbers in and discouraging movement of harvested deer carcasses from the area where CWD has been found.
MDC is working with hunters to limit the threat CWD from other states by restricting transportation of harvested deer carcasses into Missouri.
MDC has also been working with the public to limit the spread of CWD to other deer by restricting feeding of deer and eliminating the antler-point restriction in Missouri’s six-county CWD Containment Zone.
Captive-cervid facilities must help limit CWD
Missouri’s first cases of CWD were found in captive-deer hunting facilities. Initial cases of CWD in several other states have also been found in captive facilities. Thirteen states prohibit captive white-tailed or mule deer.
Missouri’s captive-cervid industry includes 47 big-game hunting preserves and 253 wildlife breeders, with a total of approximately 9,000 white-tailed deer. This captive-cervid industry plays a critical role in detecting cases of CWD in captive animals and in limiting the spread of the disease.
MDC has been working with the Missouri Department of Agriculture, captive deer and elk associations, hunters, landowners, and others on ways to limit the spread of CWD and other infectious diseases within and between captive cervids and free-ranging deer.
How captive-cervid facilities can help
Improve fencing standards. CWD is spread both directly from deer to deer and indirectly to deer from infected soil and other surfaces. Current fencing standards for captive-cervid facilities do not prevent direct contact between captive and free-ranging deer.
Prohibit cervids at animal-auction facilities and exhibitions. Current requirements for holding captive cervids at animal-auction facilities and exhibitions do not prevent direct or indirect contact among different groups of captive deer.
Prohibit the importation of live deer. Importing captive deer into Missouri is allowed and can bring CWD and other diseases into the state. Of the 37 states that have captive-deer breeding and big-game hunting preserves, approximately 20 have closed their borders to the importation of live deer.
Make testing and certification mandatory. Participation by captive-cervid operations in the Missouri Department of Agriculture’s CWD Herd Certification Program is currently only voluntary.
How hunters can help
Practice proper carcass disposal
Deer hunters play an important role in preventing the spread of CWD, which can be spread through carcasses of diseased deer, which can remain infectious for years. Carcass parts known to concentrate CWD include brain, spinal cord, eyes, spleen, and lymph nodes. Moving harvested deer that still have these parts can spread CWD to other areas.
MDC strongly encourages hunters who harvest deer in the Containment Zone to not take whole deer carcasses out of the Zone, or carcass parts that contain brain, spinal cord, eyes, spleen, or lymph nodes. Items that are safe to transport are:
- Meat that is cut and wrapped,
- Meat that has been boned out,
- Quarters or other portions of meat with no part of the spine or head attached,
- Hides or capes from which all excess tissue has been removed,
- Antlers, including antlers attached to skull plates or skulls cleaned of all muscle and brain tissue, and
- Finished taxidermy products.
The Missouri Department of Conservation also encourages all deer hunters throughout the state to properly dispose of carcasses from harvested deer to prevent the spread of infectious diseases, such as CWD.
- Remove meat in the field and leave the carcass behind. Bury the carcass if possible.
- If processing harvested deer in camp or at home, place carcass parts in trash bags and properly dispose of them through a trash service or landfill.
- Take harvested deer to a licensed commercial processor to assure proper carcass disposal.
- For taxidermy work, use a licensed taxidermist to assure proper carcass disposal.
Take proper precautions with deer meat
While there is no evidence from existing research that CWD can spread to people or domestic livestock, the Chronic Wasting Disease Alliance recommends the following common-sense precautions when handling deer or other cervids that may have been exposed to CWD:
- Do not handle or consume any animal that is acting abnormally or appears to be sick.
- Contact your state game and fish department if you see or harvest an animal that appears sick.
- Wear latex or rubber gloves when field-dressing deer or other cervids.
- Bone out meat from the animal. Don’t saw through bone and avoid cutting through brain or spinal cord (backbone).
- Minimize handling of brain and spinal tissues.
- Wash hands and instruments thoroughly after field dressing is completed.
- Avoid consuming brain, spinal cord (backbone), eyes, spleen, tonsils and lymph nodes of harvested animals. Normal field dressing coupled with boning-out a carcass will remove most, if not all, of these body parts. Cutting away all fatty tissue will remove remaining lymph nodes.
- Avoid consuming meat from any animal that tests positive for CWD.
Don’t bring deer carcasses from other states
The importation, transportation or possession of deer and other cervid carcasses or carcass parts taken from or obtained outside of Missouri is prohibited, except the following:
- Meat that is cut and wrapped
- Meat that has been boned out
- Quarters or other portions of meat with no part of the spinal column or head attached
- Hides or capes from which all excess tissue has been removed
- Antlers attached to skull plates or skulls cleaned of all muscle and brain tissue;
- Upper canine teeth
- Finished taxidermy products
People may transport carcasses or parts of carcasses with the spinal column or head attached into Missouri only if they report the action to MDC by calling 877–853–5665 within 24 hours of entering the state. They must then take the carcasses or parts of carcasses to a licensed meat processor or taxidermist within 72 hours of entry. Licensed meat processors and taxidermists shall dispose of the discarded tissue in a properly permitted landfill.
Don’t feed deer in north-central Missouri
MDC has placed a restriction on activities that are likely to unnaturally concentrate white-tailed deer and promote the spread of CWD. The ban on the placement of grain, salt products, minerals, and other consumable natural or manufactured products is limited to the CWD Containment Zone comprised of Adair, Chariton, Linn, Macon, Randolph, and Sullivan counties.
The regulation includes exceptions for backyard feeding of birds and other wildlife within 100 feet of any residence or occupied building or if feed is placed in such a manner to reasonably exclude access by deer. The regulation also includes exceptions and normal agricultural, forest management, crop, and wildlife food-production practices. Hunters and landowners should make existing mineral blocks inaccessible through removal, fencing or covering. Farmers are encouraged to remove salt and minerals when livestock are not present to minimize use by deer.
Harvest more young bucks in north-central Missouri
MDC has rescinded the antler-point restriction (four-point rule) in the CWD Containment Zone comprised of Adair, Chariton, Linn, Macon, Randolph and Sullivan counties. The reason for the regulation change is that management strategies, such as antler-point restrictions, protect yearling males and promote older bucks. Yearling and adult male deer have been found to exhibit CWD at much higher rates than yearling and adult females, so a reduction in the number of male deer can help limit the spread of CWD. The dispersal of yearling males from their natal or birth range in search of territory and mates is also one of the primary ways CWD spreads.
Test deer harvested in or near the Zone
A system for Missouri hunters statewide to have harvested deer tested for CWD is not available. MDC will continue to work with hunters in the six-county area of north-central Missouri where CWD has been found to test harvested deer for CWD.