Chronic Wasting Disease

What is Chronic Wasting Disease?
Chronic Wasting Disease (CWD) is a contagious, fatal neurologic disease of cervids which threatens both free-ranging and captive populations. CWD is classified as a transmissible spongiform encephalopathy (TSE), and shares certain characteristics with Scrapie in sheep and bovine spongiform encephalopathy (Mad Cow Disease) in cattle. CWD is always fatal.

How is CWD transmitted?
Researchers believe that CWD is transmitted laterally between animals and through contact with infected bodily fluids (saliva, urine, blood) or feces. Contaminated surfaces and environments can also be a source of transmission, as decontamination of the infectious agents can be difficult. Prions from infected carcasses and bodily waste may remain in certain soils for many years as they have shown to be very resistant to most disinfectants, as well as heat and ultraviolet radiation.

What are the symptoms of CWD?
Typically, cervids develop progressive weight loss and become severely emaciated before death. Behavioral changes, including head tremors, teeth grinding, repetitive walking and difficulty swallowing resulting in excessive salivation are all signs of this disease. It is important to note that behavioral changes are sometimes subtle, especially in the early stages of the disease, and most animals die within a few months of displaying clinical signs (although some may live for up to a year or more).

How can I prevent my herd from contracting CWD?
There are no treatments or vaccines for CWD.

Who has to test for CWD?
All domestic cervidae producers are required to test their animals for CWD. If you are a producer and have questions about testing requirements, please contact us. Additionally, the Idaho Department of Fish and Game is working with hunters for sample collection and testing for CWD in wild Cervidae.

USDA has a document outlining how to collect samples for CWD. Once a sample has been collected, you can submit it to an approved lab for CWD testing.

Chronic Wasting Disease is a reportable disease in Idaho.

If you have a question that is not covered here, please contact us.

Color version of United States Department of Agriculture Logo with blue USDA letters and a dark green field design underneath.

USDA APHIS

Information on CWD.

Elk, fallow deer and reindeer that are owned by a person.

Information on CWD in Idaho wildlife.