Chronic Wasting Disease
What is Chronic Wasting Disease (CWD)?
CWD is a neurological (brain and nervous system) disease of deer and elk known to occur in limited geographical locations in North America. The disease belongs to a family of diseases known as transmissible spongiform encephalopathies (TSE). These diseases are caused by an abnormal form of a protein called a prion. CWD is a slow accumulation of abnormal prions in the brain and lymphatic tissues of deer and elk that ultimately results in the death of the animal. While CWD is similar to mad cow disease in cattle and scrapie in sheep, there is no known relationship between CWD and any other TSE of animals or people. In deer and elk there is no practical test of live animals to detect CWD and there is no known treatment or vaccine.
How is it spread?
It is not known exactly how CWD is spread. Experimentally, the disease can be spread both directly (animal to animal contact) and indirectly (soil or other surface to animal). It is thought that the most common mode of transmission from an infected animal is via saliva, feces and possibly other body secretions. There is evidence that people moving live infected animals have spread the disease over long distances.
Is it dangerous to humans?
There currently is no convincing evidence that the agent of CWD affects humans. However, public health officials recommend that human exposure to the CWD agent be avoided as they continue to research the disease. This includes not eating meat from known infected animals, or animals that appear sick, and avoid eating the brain, spinal cord, eyes, lymph nodes, spleen, and tonsils where the abnormal prion accumulates.
Where has it been found?
Efforts to control the spread of chronic wasting disease (CWD) in free-ranging deer in Hampshire County by DNR, landowners and hunters are ongoing. In the 2012 deer seasons, samples from 672 hunter-harvested deer brought to game checking stations in Hampshire County, two stations in northern Hardy County and one station in northern Morgan County were tested for CWD. Sixteen samples were found to have the abnormal protein associated with CWD. CWD has now been detected in a total of 131 deer in Hampshire County and two deer in Hardy County. Lowering encounter rates between infected and non-infected animals by prohibiting artificial supplemental feeding and baiting are generally accepted management practices for slowing the spread of an infectious disease among wildlife and initiating these prohibitions on a statewide or regional basis for deer is a major tool used by other states combating CWD. Currently (February 2013) in West Virginia all of Hampshire County, the northern portion of Hardy County north of Corridor H and State Route 55 and the portion of Morgan County west of Route 522 has regulations prohibiting the baiting and feeding of deer. The Virginia Department of Game and Inland Fisheries and the Maryland Department of Natural Resources have detected CWD positive deer adjacent to Hampshire County in Frederick and Alleghany counties respectively. CWD was first detected in captive deer by the Pennsylvania Department of Agriculture in Adams County. Since then, the Pennsylvania Game Commission and has detected CWD in free-ranging deer in Blair and Bedford counties. Considering the CWD management actions available, documented disease transmission risks associated with artificial supplemental feeding and baiting of deer and the current known distribution of CWD in West Virginia, it would be wise to prohibit and discourage the artificial supplemental feeding and baiting of deer in Hampshire County and in the surrounding counties of Grant, Hardy, Mineral and Morgan
What is being done about the recent discovery of CWD in WV?
The discovery of CWD in Hampshire and Hardy counties in WV, represents a significant threat to the state’s white-tailed deer. The disease does not cause an immediate widespread die-off of deer, but if allowed to spread will cause long-term damage to the herd. Those that have tried to predict the outcome of the disease on a deer population have described the disease as a 30- to 50-year epidemic. Due to the uncertain ramifications that CWD may have on the white-tailed deer resource in West Virginia, the WVDNR is taking immediate action to gather more information on the prevalence and distribution of the disease in the area surrounding the known infected deer. This goal will be accomplished by increasing the number of deer tested with the help of other state and federal agencies, and local landowners. To detect CWD that may be present in only a few animals, a large number of samples need to be tested. Because of the many scientific uncertainties regarding the basic biology and ecology of CWD, there are no proven solutions to combating CWD once present in free-ranging deer. Thus management actions will be adaptive and based on the findings of the immediate and future surveillance.
How can you tell if a deer has CWD?
Infected animals may not show any symptoms of the disease. In some stages of the disease, however, infected animals begin to lose control of bodily functions and display abnormal behavior such as staggering or standing with very poor posture and they lose fear of humans. Infected animals become very emaciated (thus wasting disease), appear in very poor body condition, and often stand in or near water and drink excessively. Drooling or excessive salivation may be apparent. However, these symptoms are not unique to CWD and are also characteristic of diseases other than CWD.
What Can Hunters Do?
- If you kill a severely emaciated (very skinny) deer or a deer that is obviously sick contact the WV DNR Wildlife Resources Section office nearest you. Don’t feed or bait deer. These practices concentrate deer, increase the likelihood of spread of any disease present in the deer herd, and may introduce foreign contaminants via the feed or bait. Harvest adequate numbers of antlerless deer to maintain deer populations in balance with natural food supplies. A deer population in balance with available habitat is healthier and better able to fight diseases. Use caution in spreading urine based lures in the environment and avoid placing deer lures on the ground or on vegetation where deer can reach them. Placing them out of reach of deer still allows air circulation to disperse the scent. If you plan to hunt deer or elk in a state known or suspected to harbor CWD follow that state’s rules on removing animals from the area. Bring back only boned out meat and thoroughly cleaned skull plates and antlers. If you hunt in Hampshire County, dispose of the non-edible portions of your deer in a responsible matter and cooperate with WVDNR requests for information and samples needed for CWD testing. If you observe live deer or elk being transported in a truck or trailer notify your local DNR office as soon as possible.
Chronic Wasting Disease Alliance www.cwd-info.org