Chronic Wasting Disease

Chronic wasting disease (CWD) is a fatal nervous system disease known to naturally infect white-tailed deer, mule deer, moose and elk. It belongs to the family of diseases known as transmissible spongiform encephalopathies (TSE) or prion diseases. Though it shares features with other prion diseases, like mad cow disease in cattle and scrapie in sheep, it is a distinct disease known to only affect members of the deer family. CWD has been discovered in wild deer, elk, or moose in 15 states and two Canadian provinces. Extensive information about CWD in North American [exit DNR] can be found on the CWD Alliance web pages.

For a summary of CWD in Wisconsin plus additional information about CWD in western states view the Know CWD website [exit DNR].

CWD Response Plan

The DNR has recently completed a 15 year response plan which will be in place 2010-2025. The main goal for the management of CWD over the next 15 years is to minimize the area of Wisconsin where CWD occurs and the number of infected deer in the state. Please view the CWD response plan page for additional details.

Wisconsin Efforts

An extensive CWD surveillance program has been conducted in Wisconsin since 2002. Sample intensity has been sufficient in the majority of the state to have a high degree of confidence that CWD would have been detected if it exists at 1% prevalence. For details on the numbers tested and positive deer please view the test results page.

Analysis of the sex and age composition of positive deer has shown that very few fawns are infected; only 27 out of more than 15,500 tested. Disease prevalence increases with age and the rate of increase is faster in males than in females. Only 4-6% of yearling females and males from the core area in southern Wisconsin have tested positive for CWD. This increased to 7% of females and 16% of males for deer 2 years old or older.

There are consequences to not attempting to control the disease or an inadequate response: the prevalence and geographic distribution of CWD will increase and there will be long-term impacts on the deer hunting culture of Wisconsin and related industries and businesses. The results of ongoing research studies are needed to better understand the dynamics of the disease, its pattern of increase and spread, the role of environmental transmission, and the effect of management actions on the disease.

Questions for Wildlife Management