What causes chronic wasting disease?

Chronic wasting disease is caused by a misfolded protein called a prion. All mammals produce normal prions that are used by cells, then degraded and eliminated, or recycled, within the body. When disease-associated prions contact normal prions, they cause them to refold into their own abnormal shape. These disease-associated prions are not readily broken down and tend to accumulate in--and damage--lymphatic and neural tissues, including the brain.

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What are the visual signs of chronic wasting disease?

Chronic wasting disease (CWD) has an extended incubation period averaging 18–24 months between infection and the onset of noticeable signs. During this time frame animals look and act normal. The most obvious sign of CWD is progressive weight loss. Numerous behavioral changes also have been reported, including decreased social interaction, loss of...

What is chronic wasting disease?

Chronic wasting disease (CWD) is a fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk, and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among...
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Date published: June 19, 2018

New Approach May Detect Chronic Wasting Disease Earlier, at Less Cost

A new statistical approach to disease surveillance may improve scientists’ and managers’ ability to detect chronic wasting disease earlier in white-tailed deer by targeting higher-risk animals. This approach can also provide financial and personnel savings for agencies that are required to monitor for wildlife diseases, including the National Park Service, or NPS. 

Date published: October 5, 2016

Chronic Wasting Disease in White-Tailed Deer

Chronic wasting disease may have long-term negative effects on white-tailed deer, a highly visible and economically valuable keystone species, according to a new study from the USGS and published in Ecology. 

Date published: May 25, 2011

Environmental Persistence of Chronic Wasting Disease Exacerbates Deer Population Declines


Long-term impacts of the chronic wasting disease (CWD) epidemic in North American deer, elk and moose will depend on how the disease persists in the environment, according to a new U.S. Geological Survey study.

Date published: May 17, 2011

Lichens May Aid in Combating Deadly Chronic Wasting Disease in Wildlife

Certain lichens can break down the infectious proteins responsible for chronic wasting disease (CWD), a troubling neurological disease fatal to wild deer and elk and spreading throughout the United States and Canada, according to U.S. Geological Survey research published today in the journal PLoS ONE. 

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Map of North America showing locations where chronic wasting disease has been detected.
November 23, 2021

Distribution of Chronic Wasting Disease in North America

Distribution of Chronic Wasting Disease in North America, updated November 23, 2021

Image shows a mule deer doe walking on grass, facing right
May 26, 2016

Mule Deer

A female mule deer in Texas, quite far from its type location. Credit: Alex Demas, USGS.

Photo pf a bull elk with chronic wasting disease.
September 9, 2012

A bull elk with chronic wasting disease

A bull elk with chronic wasting disease at Wind Cave National Park.  The emaciated appearance and drooping ears are characteristic of latter stages of infection.

USGS CoreCast
September 12, 2011

Disease Detectives: Investigating the Mysteries of Zoonotic Diseases

Zoonotic diseases are those that are spread between wildlife and humans, and are an increasing health threat in the U.S. and throughout the world. As such diseases emerge, scientists with the U.S. Geological Survey and other wildlife health agencies must embark upon complex investigative work to determine what these diseases are, where they come from, and how they’re

Deer with Chronic Wasting Disease
November 30, 2000

Deer with Chronic Wasting Disease

This deer shows visible signs of chronic wasting disease. 

Attribution: Ecosystems