Chronic Wasting Disease

Summary

Chronic Wasting Disease (CWD) is an always-fatal, progressive, degenerative neurological disease occurring in farmed and free-ranging deer, elk, and moose that is classified to the family of diseases called transmissible spongiform encephalopathies. Presently, state fish and wildlife agencies are forced to divert funds from other conservation projects to perform surveillance and monitoring of CWD within their jurisdictions.

Background

First recognized in 1967 as a clinical ‘wasting’ syndrome among captive mule deer in Colorado, CWD remains a considerable threat to cervid populations across the country. CWD belongs to the family of diseases known as transmissible spongiform encephalopathies (TSEs). TSEs include a number of different diseases affecting animals or humans including bovine spongiform encephalopathy (commonly known as mad cow disease) in cattle, scrapie in sheep and goats, and Creutzfeldt-Jakob disease in humans.  Although CWD shares certain features with other TSEs, it is a distinct disease affecting only deer, elk, and moose.

CWD is a slow and progressive disease with a lengthy incubation period. Because of this, infected deer, elk, and moose may not present visible symptoms of the disease until years after the time of infection. Even as visible symptoms, such as weight loss, stumbling and tremors, become observable, the commonality of these symptoms among cervid maladies, such as epizootic hemorrhagic disease (EHD), prevents CWD from being readily diagnosed. As it currently stands, there is no way to conclusively identify the presence of CWD within an animal until a necropsy has been performed. With no known treatment or vaccine available, CWD continues to prove fatal in all documented cases.

The agent that causes CWD and other TSEs has not been completely characterized. However, the theory supported by most scientists is that TSE diseases are caused by abnormal forms of proteins, known as prions. The exact mechanism of transmission is unclear, although evidence suggests CWD is transmitted directly from one animal to another through bodily fluids and tissues. Further research also indicates that CWD-causing prions can persist in soil for several years, potentially binding to plant life in the area. As the list of means of transmission expands, CWD is of increasing concern for wildlife managers across North America.

Since first identified, CWD has been documented in both wild and captive cervid populations throughout 26 states and three Canadian provinces. Where present, localized infection rates among wild and captive cervids can reach upwards of 25% and 79%, respectively. The lack of definitive information regarding CWD, coupled with the disease’s potential to decimate large portions of North America’s cervid population, establishes a critical need for additional research to ensure that our nation’s professional wildlife managers and agencies have accurate and reliable scientific information at their disposal on which to base future management decisions.

Recent Activity

Bipartisan bills have been introduced in each chamber of Congress by Congressional Sportsmen’s Caucus (CSC) Members.

The Chronic Wasting Disease in Cervidae Study Act was introduced by Congressman Ralph Abraham (LA) in the House (H.R. 837) in January 2019, and introduced by Senator John Barrasso (WY) in the Senate (S. 382) in February 2019. Both bills were co-sponsored by many other CSC Members and call on the Secretaries of Agriculture and the Interior to partner with the National Academy of Science to study and identify the ways in which CWD is transmitted between and among wild farmed cervids.

On February 28, CSC Member Senator Cindy Hyde-Smith (MS) introduced the Detection, Enhanced Education, and Response (DEER) Act of 2019, which allocates resources to the USDA to conduct CWD surveillance and other monitoring efforts.

On March 6, Congressman Ron Kind (WI) and Senator John Tester (MT) introduced the Chronic Wasting Disease Management Act (H.R. 1550/S. 689) to provide state and tribal agencies funding to conduct additional surveillance and monitoring for the disease and to support applied research regarding its causes and methods to control the spread.

 

Last updated 4/1/2019

Share this page

Your opinion counts

Which of the following do you think would most effectively support increasing hunting participation numbers?

Vote Here
Get Involved

We work hard to educate elected officials about issues important to you, but we can't do it alone. Find out how you can get involved and support CSF.

Read More