About CWD
Chronic Wasting Disease (CWD) is a fatal disease that affects the cervid population of the North American continent. Over 100 million white tail, mule deer, moose and elk are at risk.
CWD belongs to the family of diseases called Transmissible Spongiform Encephalopathies (TSE). These diseases are unique and remain a mystery in many ways. They cause proteins normally found in animals to behave uncharacteristically, destroying cells in brain and spinal tissues, ultimately killing the host. TSEs are not viral or bacterial and have no known cure.
The first known case of a TSE was scrapie in sheep thought to have started in the 1700's in Europe. Since then, TSEs have been identified in many different species including squirrels, mink, felines, cattle (Mad Cow Disease or BSE), deer, moose, and elk (CWD) and humans (CJD). In most cases, research shows TSEs develop in new species from exposure to TSEs in other species. For example, a human TSE named vCJD infects humans after consumption of BSE (Mad Cow) infected cattle.
Scrapie was first thought to occur in North America in the 1940's. CWD was first identified in a research station in Fort Collins, Colorado in 1967. Evidence shows that CWD transferred from Scrapie. Each time a TSE transfers or develops into a new species it has unique characteristics and causes new challenges. For instance, BSE (mad cow) is spread only by contaminated feed.
Chronic Wasting Disease presents a much more difficult situation than similar TSEs. It is known that deer and elk contract the disease through animal-to-animal contact, exposure to a contaminated environment, or to an infected carcass – making it much more virulent than Mad Cow. Once CWD is in an environment, it can remain contaminated for many years and cannot be removed. The infectious agent survives high temperatures, traditional disinfectants, and radiation. Science suggests that all deer and almost all elk are susceptible. There is no vaccine to prevent an animal from contracting the disease and no treatment for infected animals.
Each year new pockets of CWD are found throughout the country. Areas where CWD exists generally increase in size as does the rate of infection. Once CWD has been found in a location it has never gone away.
There is disagreement between scientists about the level of CWD infection wild herds in North America will eventually achieve. Some population studies show that ultimately all the deer and elk will succumb. Some scientists believe that a certain level of infection will always remain and there will always be surviving animals. No legitimate study shows that CWD will go away on its own.
There is little disagreement among scientists that CWD is a significant problem and is having a negative impact on the North American deer and elk populations. Deer and elk are an important part of our ecosystem and national economies. Currently there are no known cases of CWD crossing to other species. However, as more of the environment is contaminated and more deer and elk carry CWD, the risk that it will cross to other species increases.