Chronic Wasting Disease (CWD) is a disease of deer and elk caused by an abnormally shaped protein, called a prion that can damage brain and nerve tissue. The disease is most likely transmitted from one animal to another through shedding of abnormal prions in saliva, feces, urine, and other bodily fluids or tissues. CWD is a slow and progressive disease without any known treatment or vaccine.
All farmed cervidae producers are required to test their herds for CWD. From each herd, all farmed cervidae 12 months of age and older that die or are slaughtered must be tested for CWD. Tissue samples are tested for CWD at the University of Minnesota Veterinary Diagnostic Laboratory.
In order to maintain accurate CWD surveillance information, producers must report to the Board of Animal Health, all deer or elk that die or are moved out of the herd to other locations.
Minnesota’s endemic area
The Board has expanded the endemic area for CWD in the state based on information from the Minnesota DNR on additional CWD positive wild deer and their southeast deer movement study, which shows average deer movements encompass a greater area than previously understood. Information from the Wisconsin DNR about a CWD positive wild deer harvested near the Mississippi River in Vernon County, Wisconsin is also part of the expansion.
Additional CWD positive wild white tailed deer were harvested during the 2018 fall hunting season and in special hunts that occurred in late 2018 and early 2019. Wild deer found dead were also reported to the DNR and four of these deer tested positive for CWD including an adult doe found dead in Crow Wing County. This is the first CWD positive wild deer found in central Minnesota. A total of 51 CWD positive wild deer have been identified in Minnesota since the fall of 2016.
The Board will now include a minimum distance of 15 miles around any confirmed case of CWD in the wild based on the findings of the DNR’s southeast deer movement study. This distance will encompass more of a deer’s average movement to better address the potential for exposure of farmed cervid herds to CWD infected wild deer. The Board includes all of Houston County in the endemic area as most of the County was within 15 miles of a confirmed case of CWD in the wild with the detection of a CWD positive wild deer in Vernon County, Wisconsin. The map linked below depicts the perimeter of the endemic area in Minnesota.
The designation of this area impacts farmed cervidae herds found within the area. Farmed cervidae in these herds are restricted from moving to other areas of the state until the producer can demonstrate the herd is maintained in such a way to prevent commingling of farmed and wild cervidae. Commingling of farmed and wild cervidae can occur across a fence and additional exclusionary barriers must be constructed and approved by the Board to prevent this commingling. Producers that have established exclusionary fencing or barriers must be inspected by the Board before the movement restriction on their herd is released.
Click here to view the current endemic area map.
If additional CWD positive free-ranging cervidae are found in subsequent surveillance of the wild deer herd, the endemic area may need to expand. The Board can designate a larger geographic area of the state if necessary to prevent the spread of CWD.
Click here to view the distribution of CWD in North America.