Chronic Wasting Disease

About Chronic Wasting Disease

CWD is a neurologic disorder that causes the brain to degenerate and develop cavities becoming sponge like in appearance. It is caused by abnormally folded proteins called prions. CWD is contagious between animals by either direct or indirect contact with infected animals or their habitat. It is not known if CWD is contagious to people.

Commonly Affected Species:

Signs Of Disease

Animals infected with CWD are typically thin and show neurologic signs. The most common sign of CWD is lack of feeding, increased drinking and excessive salvation and urination. Behavioral signs include loss of fear of humans and loss of awareness of their surroundings.The most common signs of CWD in live cervids are emaciation and neurological signs. There are no typical lesions seen in animals that die of CWD but consistent signs include poor body condition and aspiration pneumonia.

Where is Disease Found?

CWD has been documented in numerous states in the US, several Canadian provinces (Ontario, Saskatchewan, Alberta), South Korea, Norway and Finland in a variety of cervid species. It has been found in both captive and wild cervids. The current distribution of CWD in North America can be found in various links provided here. As of November, 2021, CWD is present in free-ranging deer in Idaho.

How Can I Protect Myself?

There have been no documented human infections with CWD. However, as a precautionary measure it is recommended to bone out the animal, and not to eat the brain or spinal cord of wild cervids. Harvested animals can be tested for CWD by bringing the carcass with an intact head to an Idaho Department of Fish and Game check station or an Idaho Department of Fish and Game Regional office.

Samples to Collect

Live animals can be tested for CWD by collecting rectal or tonsil biopsy samples, placing the samples in 10% buffered formalin, and submitting the samples to a diagnostic laboratory for testing, usually with an IHC test. Dead animals can be tested by collecting lymph nodes or the obex and submitting them as fresh samples for an ELISA test or in formalin for an IHC test. Samples should not be frozen. Samples need to collected by trained staff. Animals can be sampled by bringing the carcass to a check station, an Idaho Department of Fish and Game Regional Office, or by contacting a local Conservation Officer.

Can I Eat The Meat?

There is no scientific evidence that CWD is associated with illness in humans or livestock. The World Health Organization in Geneva, Switzerland and the Centers of Disease Control in Atlanta, Georgia have concluded that there is currently no evidence that CWD in deer and elk is transmitted to humans. Human Creutzfeldt-Jakob disease (CJD) does not occur at a higher rate in CWD endemic areas. However, as a safety precaution, both organizations as well as numerous state wildlife management agencies, recommend that no part or product of any animal with evidence of CWD or other transmissible spongiform encephalopathies should be fed to any species (human, domestic or captive animal).

What is IDFG doing to help manage this disease?:

IDFG has been conducting surveillance for CWD in deer and elk since 1997. Samples are collected from deer, elk and moose that are killed on roads, by hunters, and from animals with possible clinical signs of CWD.

IDFG has developed a CWD response plan in the event CWD is found in free-ranging or captive cervids in Idaho.

Currently IDFG is doing the following:

Cooperating with the Idaho State Department of Agriculture (ISDA) to implement CWD rules for captive cervids
Prohibiting the importation of mule deer, white-tailed deer and moose by private parties
Conducting surveillance of deer and elk primarily using samples collected at hunter check stations, taxidermists, and targeted groups of animals.
Providing public education about this disease.

How do I learn more about this disease?