Chronic Wasting Disease
What is Chronic Wasting Disease?
Chronic Wasting Disease (CWD) belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). TSEs cause a degeneration of the brain in cervids such as deer, elk and moose.
When was CWD first discovered?
CWD was first recognized in 1967 in captive mule deer in Colorado. Since then, CWD has been documented in free-ranging and captive white-tailed deer, as well as in mule deer, elk and moose.
In what states has CWD been found?
CWD has been documented in both captive and free-ranging deer in Missouri, along with neighboring Kansas and Nebraska. It has been documented in free-ranging deer in neighboring Illinois and in captive elk in neighboring Oklahoma. CWD has also been documented in both captive and free-ranging members of the deer family in Colorado, Minnesota, New York, South Dakota, Wisconsin and the Canadian provinces of Alberta and Saskatchewan. Maryland, New Mexico, North Dakota, Utah, Virginia, West Virginia and Wyoming also have documented cases of CWD in free-ranging members of the deer family. Michigan and Montana have documented cases of CWD in captive members of the deer family.
Where has CWD been found in Missouri?
Three cases of CWD have been found in captive white-tailed deer since February 2010 at a 3,800-acre private, captive-hunting preserve in Linn and Macon counties. Two positive results were detected from test samples taken from free-ranging adult bucks harvested in Macon County by Missouri hunters in 2011. The two bucks that tested positive were harvested within two miles of the captive-hunting preserve. These two positive test results are the first for free-ranging deer in Missouri.
How is CWD spread?
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 by animal-to-animal contact or by animal contact with soil that contains prions from urine, feces or the decomposition of an infected animal. CWD can come into a state through the natural movement of free-ranging deer and elk or by the interstate shipment of hunter-harvested or captive white-tailed deer, mule deer or elk.
What is Missouri doing to protect the state against CWD?
Missouri has a Cervid Health Committee and a CWD Contingency Plan to address the threat of CWD to Missouri. The Committee is composed of wildlife biologists, veterinarians and other animal-health experts from Missouri departments of Conservation, Agriculture and Health and Senior Services, along with the U.S. Department of Agriculture. The agencies are working together to help keep deer and elk from CWD-infected states out of Missouri and to examine sources of infection that already exist in the state.
From 2002 to 2011, MDC tested more than 34,000 free-ranging deer and found two CWD-positive cases. Targeted testing of deer continues. The Missouri Department of Agriculture monitors captive deer, elk and other cervids in Missouri.
What are the symptoms of CWD?
Deer or other cervids with CWD show changes in natural behavior and can exhibit extreme weight loss, excessive salivation, stumbling and tremors. CWD is fatal to the infected animal, but it can take months or years before symptoms of infection appear.
How is CWD diagnosed?
CWD can only be confirmed in deer by laboratory testing of brain or lymph tissue.
Can people get CWD?
The Missouri Department of Health and Senior Services (MDHSS) says there is no scientific evidence that CWD is transmissible to humans through contact with or the consumption of deer meat. 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. While there is no scientific evidence that CWD is transmissible to humans or animals other than deer and other cervids, health officials caution that consumption of these parts is not recommended. They also advise people to not eat meat from animals known to be infected with CWD or that exhibit signs of any disease.
Can livestock get CWD?
The Missouri Department of Agriculture (MDA) says there is no evidence from existing research that CWD can spread to domestic livestock, such as sheep or cattle.
What can the public do to help?
Help from the public is needed to ensure sick deer are reported to MDC for testing. People who observe or harvest sickly deer should contact their nearest MDC office or conservation agent.
Should hunters take precautions when field dressing or processing deer meat?
There is no evidence that CWD affects humans. Hunters concerned about any deer-related disease or parasites should wear rubber or latex gloves while field dressing and processing deer.
Can hunters bring harvested deer or other cervids to Missouri from other states?
According to the Missouri Wildlife Code, the importation, transportation, or possession of cervid (such as deer, elk, moose) carcasses or cervid 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
- Antlers attached to skull plates or skulls cleaned of all muscle and brain tissue
- Upper canine teeth or
- 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.
