What is Chronic Wasting Disease?

Chronic Wasting Disease (CWD) is a degenerative, fatal brain disease that affects white-tailed deer, elk, mule deer, moose and potentially woodland caribou.

Chronic Wasting Disease belongs to a group of diseases called transmissible spongiform encephalopathies. While CWD is similar to bovine spongiform encephalopathy (also known as BSE or "mad cow disease") in cattle, there is currently no evidence that it can be transmitted to humans or to domestic livestock such as cattle, horses and pigs.

There is no evidence that any Ontario deer, elk, moose or woodland caribou are infected with CWD.

History of CWD

United States

CWD was first described in captive mule deer in Colorado in 1967. It was first detected in wild elk in Colorado in 1981. Scientists have suggested that CWD could have been present in wild deer in Colorado for some time prior to 1981.

Since then, in the United States, it has been diagnosed in wild mule deer, white-tailed deer and/or elk in Colorado, Illinois, Kansas, Maryland, Minnesota, Missouri, Nebraska, New Mexico, New York, South Dakota, North Dakota, Texas, Virginia, Utah, West Virginia, Wisconsin, Pennsylvania and Wyoming. CWD has also been found in captive elk and/or deer in Michigan, Colorado, Kansas, Minnesota, Montana, Nebraska, New York, Oklahoma, Pennsylvania, South Dakota, Missouri, Wisconsin and Wyoming.

In 2005 and 2006, the Colorado Division of Wildlife reported detection of CWD in a small number of wild moose. In 2008, CWD was discovered in a wild moose in Wyoming. These are the first known cases of CWD in moose.

Canada

In Canada, CWD was confirmed in captive elk in Saskatchewan in 1996, and in a wild mule deer in 2001. Since then it has persisted in Saskatchewan's wild mule deer and white-tailed deer populations. CWD has also been confirmed in Alberta, in wild mule deer (2005) and captive white-tailed deer and elk (2002). The captive herds in Saskatchewan and Alberta were subsequently destroyed to prevent the spread of CWD. CWD was detected in several mule deer imported from the United States and housed at the Toronto Zoo in 1977. This herd died off and was not replaced.

Source:  Chronic Wasting Disease Alliance (www.cwd-info.org)

For more information the following websites are suggested.  Note that some of the Web sites linked below are created by or for organizations outside of the Ontario government, and those organizations are responsible for the information contained within their respective sites. These sites might not be available in French. Any specific comments or inquiries regarding those sites should be directed to the individual organization. 

• Ontario Ministry of Agriculture, Food and Rural Affairs - Fact Sheet:  Chronic Wasting Disease

• Canadian Food Inspection Agency - Chronic Wasting Disease (CWD) of Deer and Elk

• Chronic Wasting Disease Alliance