Chronic Wasting Disease Cases Rise in Wyoming’s Mule Deer Population

The Wyoming Game and Fish Department (WGFD) has reported an increase in chronic wasting disease (CWD) prevalence among the state’s mule deer population, according to its 2024 CWD Surveillance Report, Billings Gazette reports.

Of the 5,276 samples tested, 726 were positive, resulting in a 13.7% statewide prevalence.

The report analyzed hunter-harvested, road-killed, and targeted mule deer, white-tailed deer, elk, and moose. Key findings included:

• Mule Deer Bucks: 19.4% of hunter-harvested mule deer bucks tested positive, an increase from 18.9% in 2023.

• White-Tailed Deer Bucks: 29.2% of hunter-harvested white-tailed deer bucks tested positive, a slight decrease from 30.3% in 2023.

• Elk: 2.3% of adult, hunter-harvested elk tested positive, down from 2.8% in 2023.

• Moose: No moose tested positive for CWD.

The total number of submissions also increased slightly from 5,100 in 2023.

CWD is a fatal neurological disease affecting mule deer, white-tailed deer, elk, and moose. It belongs to the transmissible spongiform encephalopathies family, caused by misfolded proteins called prions. Currently, there is no cure or vaccine for CWD.

While no cases of CWD have been reported in humans, and there is no direct evidence that humans can contract the disease, the Centers for Disease Control (CDC) and the World Health Organization (WHO) recommend against consuming CWD-positive animals.

In 2024, CWD was detected in:

• Three new deer hunt areas: 31, 53, and 94.

• Three new elk hunt areas: 23, 84, and 126.

• Three additional elk hunt areas in early 2025: 62, 87, and 93.

• Four elk feedgrounds in western Wyoming.

To assess long-term CWD trends, WGFD calculated five-year averages for herd units. Findings include:

• Mule Deer Herds:

  • The Project Herd (Lander Region) had the highest CWD prevalence statewide at 66.3%.

  • The Shoshone River Herd (Cody Region) was second at 47.6%.

• Elk Herds:

  • The Iron Mountain Herd (southeast Wyoming) had the highest CWD prevalence at 10.1%.

  • The North Bighorn Herd (north-central Wyoming) saw an increase to 9.1% from 7% (2019-2023).

CWD prevalence is not evenly distributed across herds but often accumulates in localized hotspots.

As of 2024, WGFD considers:

• 95% of Wyoming’s mule deer hunt areas endemic for CWD.

• 62% of elk hunt areas endemic for CWD.

The department will continue annual surveillance in priority areas, with special emphasis on early detection in regions where CWD has not yet been confirmed.

CWD testing remains free for animals harvested in Wyoming, and hunters are strongly encouraged to submit samples, particularly in regions with limited data.

For more information, including the full 2024 CWD Surveillance Report, visit the WGFD CWD Information Page.