Testing for Chronic Wasting Disease (CWD) is being conducted in two areas of Minnesota this fall during deer season. Testing in southeast Minnesota (deer permit areas 348 and 349) is due to a CWD positive deer found within Iowa's borders in Allamakee County, which borders Minnesota. Testing in the north metro (part of deer permit areas 601 and 236) is a precautionary measure after CWD was discovered in a captive cervid farm in North Oaks in 2012.
In addition to the DNR's disease surveillance and management within the state, importation of cervidae (moose, elk, deer, caribou) carcasses from CWD endemic areas is also restricted. Carcasses may not be imported into the state from a CWD endemic area except for cut and wrapped meat, quarters or other portions of meat with no part of the spinal column or head attached, antlers, hides, teeth, finished taxidermy mounts, and antlers attached to skull caps that are cleaned of all brain tissue. If you plan to hunt outside the state, consult the Minnesota Board of Animal Health website for a map of areas from which import is restricted.
Deer permit areas 348 & 349 stations
Southeast Registration Stations
Registration stations listed above will be open 9 a.m. to 7 p.m. during the opening weekend of the firearm's deer season. This is a voluntary surveillance for the hunters.
Extensive sampling of nearly 1,000 deer during fall 2013 in southeastern Minnesota's deer permit area 602 did not detect a single case of Chronic Wasting Disease (CWD). More than 4,000 deer have been sampled within DPA 602 since the discovery of the index case with no additional detection found which lends confidence that DNR caught the disease on the front end of the infection. DPA 602 no longer exists and its borders are dissolved back to surrounding deer permit areas.
In mid- 2012, a captive European red deer (Cervus elaphus) was found infected with CWD in a herd of approximately 400 animals in North Oaks, Minn. This marked the first time CWD was discovered in this species. In response, the Minnesota DNR collected samples from 154 deer in 2012 and another 134 in 2013 all within a 10-mile radius of the farm to test for CWD.
Sample collections included 24 vehicle-killed deer, 133 archery-killed deer from special metro hunts, and 131 deer from a city-contracted sharpshooting effort within North Oaks. All samples were negative for CWD. The Minnesota DNR plans to continue surveillance in the north metro in 2014.
Due to the discovery of CWD in Allamakee County Iowa in April 2014, the Minnesota DNR plans to conduct CWD surveillance in deer permit areas 348 and 349 along the Iowa border. The goal is to collect a minimum of 450 samples total between both permit areas.
North Metro sampling
Click to enlarge map
*In 2014, deer permit area 602 has reverted back to the former permit areas (341 and 343).
CWD (Chronic Wasting Disease) naturally occurs in North American deer, moose and Rocky Mountain Elk. It belongs to a group of infectious diseases known as "transmissible spongiform encephalopathies" (TSEs).
It is caused by an abnormal protein called a prion which affects the animal's brain and is invariably fatal. Usually, months to years pass from the time an animal is infected to when it shows signs of the disease.
The disease is found in 14 other states and two Canadian provinces, including the Midwestern states of Wisconsin, Illinois, North Dakota and South Dakota.
Typical signs of the disease include drooping head or ears, poor body condition, tremors, stumbling, increased salivation, difficulty swallowing, or excessive thirst or urination.
The diagram to the right illustrates the most common sites where prions accumulate in infected cervids.
The Minnesota Department of Natural Resources has confirmed that an adult female deer harvested during the 2010 hunting season has been diagnosed with Chronic Wasting Disease (CWD), a brain and nervous system disorder found in deer, elk and moose. This is disappointing news but the DNR is well prepared to address it.
The discovery occurred the week of Jan. 10, 2011, during laboratory analysis of more than 500 samples (lymph nodes) taken from hunter-harvested deer taken within a 20-mile radius of Pine Island in southeastern Minnesota. Initial screening of all other samples is complete. The DNR collects and evaluates lymph nodes because CWD can be detected through microscopic analysis.
The National Veterinary Services Laboratory in Ames, Iowa, confirmed the University of Minnesota's preliminary diagnosis of the single adult female white-tailed deer on Jan. 25, 2011.
At this point, no one knows. In fact, we may never know. What is known is that the "presumed positive" deer was harvested about three miles southwest of a former domestic elk farm near Pine Island. The farm's elk herd was depopulated after a seven-year-old female elk tested positive for CWD in January 2009. Three additional elk were found to be infected with CWD during the depopulation effort. The closest wild deer with CWD in Wisconsin is 150 miles from the location this CWD-suspect deer was harvested in Minnesota.
CWD is found in wild deer, elk or moose in 14 other states and two Canadian provinces, including Midwestern states of Wisconsin, Iowa, Illinois, North Dakota. For specifics, visit the CWD Alliance Website.
A map and list of states and counties with endemic areas where exportation of cervids is restricted is available from the Minnesota Board of Animal Health by clicking the Cervidae (Deer, Elk, Moose, Caribou, Reindeer) link.
The DNR has been actively on the lookout for CWD since 2002, when the disease was first found in a domestic elk farm in central Minnesota. An important management strategy for this disease is early detection. Since 2002, the DNR has tested more than 40,000 hunter-harvested, car-killed and targeted sick deer, along with 60 elk and 90 moose. Until now, laboratory analysis had never found a wild deer "presumed positive" for CWD.
That's possible but it's premature to speculate. The only way to know if other deer have CWD is to continue doing surveillance based on enacting our CWD Response Plan.
Based on the fact that only one deer has tested positive for CWD among more than 500 samples, the rate of occurrence is likely low. Still, people with venison in their freezer from this area should know the following:
So, people with venison in their freezer that was harvested from this area will need to make decisions based on the information above. The Minnesota Department of Health – not the DNR – provides guidance to citizens on food consumption issues.
CWD causes a characteristic spongy degeneration of the brains of infected animals resulting in emaciation, abnormal behavior, loss of bodily functions and death. CWD belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). Though many observers try to compare CWD with "mad cow disease", the diseases are distinctly different.
The disease agent is a prion, an abnormal form of cellular protein that is most commonly found in the central nervous system and in lymphoid tissue. The prion "infects" the host animal by promoting conversion of normal cellular protein to the abnormal form.
The origin of CWD is unknown, and it may never be possible to definitively determine how or when CWD arose. It was first recognized as a syndrome in captive mule deer held in wildlife research facilities in Colorado in the late 1960s, but it was not identified as a TSE until the 1970s. Computer modeling suggests the disease may have been present in free-ranging populations of mule deer for more than 40 years.
It is not known exactly how CWD is transmitted. The infectious agent may be passed in feces, urine or saliva. Transmission is thought to be lateral (from animal to animal). Although maternal transmission (from mother to fetus) may occur, it appears to be relatively unimportant in maintaining epidemics.
Because CWD infectious agents are extremely resistant in the environment, transmission may be both direct and indirect. Concentrating deer and elk in captivity or by artificial feeding probably increases the likelihood of both direct and indirect transmission between individuals. Contaminated pastures appear to have served as sources of infection in some CWD epidemics. The apparent persistence of the infectious agents in contaminated environments represents a significant obstacle to eradication of CWD from either captive or free-ranging cervid populations.
The movement of live animals is one of the greatest risk factors in spreading the disease into new areas. Natural movements of wild deer and elk contribute to the spread of the disease, and human-aided transportation of both captive and wild animals greatly exacerbates this risk factor.
CWD poses serious problems for wildlife managers, and the implications for free-ranging deer, elk and moose are significant:
Improper handling of the deer can contaminate the carcass with potentially harmful bacteria and compromise food safety and quality. By implementing a few precautionary measures during field dressing, the hunter can help ensure the final product is fit to consume.
The Centers for Disease Control and World Health Organization state that there is no scientific evidence that CWD causes human Illness; however, precautions should be taken to minimize exposure.
Proper handling and refrigeration is necessary to prevent decomposition of the carcass and minimize the growth of potentially harmful bacteria. This will reduce the risk of food-borne illness due to consumption of contaminated meat.
Chronic wasting disease (CWD) is an infectious neurological disease that occurs in North American deer (Odocoileus spp.), Rocky Mountain elk (Cervus elaphus), and moose (Alces alces) and belongs to a group of diseases called transmissible spongiform encephalopathies (TSEs).
The disease is progressively fatal and has no known immunity, vaccine or treatment. Since 2002, more than 40,000 hunter-harvested and 650 opportunistic or targeted wild deer have been tested for CWD in Minnesota, with only one positive case identified in the wild.
This plan establishes general procedures to be followed for managing CWD if it is found in wild deer and procedures for wild deer surveillance if CWD is detected in a captive cervid facility or in bordering states.
If CWD is detected in wild cervids in Minnesota, the Minnesota Department of Natural Resources (MNDNR) has identified 4 primary goals of managing the disease: