What is Chronic Wasting Disease (CWD)?

Chronic wasting disease (CWD) is a fatal neurologic illness of cervids, which include deer, elk, moose, and caribou. CWD is caused by an infectious prion protein and transmitted from animal to animal through feces, saliva, urine or through contaminated environments. Most animals with CWD appear normal until the end stages of the disease when they show signs of weight loss, lethargy, drooping ears, excessive salivation and urination, and loss of fear of people. There is no cure for CWD and testing tissue collected from the head of carcasses is the only way to determine if an animal is infected with it.

The following video from the Mississippi State University Deer Ecology and Management Lab explain how prion diseases work. Additional videos cover topics such as how CWD affects deer populations, best practices for managing CWD, and more. 

Colorado and Wyoming are currently dealing with the impacts of chronic wasting disease. This video illustrates the challenges of managing the spread of the disease and how activities like wildlife feeding and baiting can increase the spread of it.

CWD health and human safety

CWD has not been shown to infect people, but research is still ongoing, and it is not known for certain if people can get infected with this disease. There is a theoretical risk to people who eat an infected animal. As a precaution, the Washington State Department of Health and the Centers for Disease Control and Prevention recommend not eating any animal that tests positive for CWD or appears to have it. WDFW and DOH also advise hunters to:

  • Avoid harvesting any animal that appears sick or behaves strangely.
  • Wear eye protection and disposable gloves while field dressing game. 
  • Thoroughly wash hands and equipment after processing carcasses. 
  • Minimize handling parts where the CWD prions accumulate, including the brain, spinal cord, eyes, spleen, pancreas, tonsils, and lymph nodes. 
  • Avoid cutting through bone, brain, or spinal cord. 
  • Disinfect processing tools by soaking in household bleach (>2% free chlorine) at a 40% solution (with water) for a minimum of five minutes. Remove any tissue pieces from tools before soaking and rinse tools after soaking. 
  • Safely discard inedible parts and any positive meat using one of the recommended methods listed on the WDFW website. Tissues from CWD-positive animals can contaminate the environment and infect other cervids. Do not dispose of infected materials on the landscape or feed to pets.

Historical information on CWD in Washington

WDFW has been proactive in its approach to CWD. The Department adopted a CWD Management Plan in December 2021, then updated the Initial Response Chapter in 2024 to reflect knowledge gained after performing a table-top exercise in response to a fictitious detection. The Plan outlines strategies for public outreach and communication, risk assessment and minimization, pre-detection surveillance, and initial emergency response to a detection of CWD.

WDFW first began limited testing for CWD in 1995. After federal funding was provided specifically for CWD testing, statewide surveillance for CWD was conducted from 2001-2011. After 2011, with funds limited, CWD testing in Washington was focused on animals showing clinical signs consistent with the disease.

In 2021, the Washington State Legislature provided funding to conduct Pre-Detection Surveillance to test harvested, road-killed, and opportunistically found dead deer in areas of eastern Washington. WDFW is coordinating with federal and other state agencies, tribes, hunting organizations, taxidermists, and meat processors to collect samples to test for CWD. Each year's activities regarding CWD are detailed in the annual reports found under Reports, plans, and other CWD resources below.

CWD across the U.S. and Canada

CWD has been detected in 35 U.S. states and four Canadian provinces. If you hunt outside of Washington, please be aware of regulations impacting the transport of deer, elk, and moose carcasses from one state or province to another. You can find carcass import regulations on this map, provided by Chronic Wasting Disease Alliance.

A map showing the existence of chronic wasting disease in the U.S. and Canada

Reports, plans, and other CWD resources

Confirmed cases of CWD in Washington

The following are confirmed cases of chronic wasting disease in Washington since the first detection in summer of 2024.

SpeciesNumber of 
positive cases		Game management unitCounty
White-tailed deer5124Spokane
White-tailed deer1117Pend Oreille