Chronic wasting disease (CWD) is slowly spreading across Wyoming. The Wyoming Game and Fish Department’s (WGFD) Wildlife Health Laboratory recently completed testing samples collected last year – from hunter check stations, roadkill and animals already found dead or in poor condition. The results show that, like prior years, the number of positive tests remains steady, according to a news release.

“We can say that the prevalence of CWD is slowly increasing in many deer and elk herd units in the state,” said Jessica Jennings-Gaines, WGFD wildlife disease specialist. “The western half of Wyoming has several deer hunt areas where CWD has not been detected, however the disease continues to spread west and was detected in two new deer and five new elk hunt areas last year.”

WGFD tested 6,701 samples from big game animals in 2022. Out of those samples, 826 tested positive for the disease. Some samples were not testable. In 2021, WGFD tested 6,884 samples with 839 positive for CWD and, in 2020, out of the 6,496 samples tested, 829 were positive.

While this shows that the ratio of tested samples and positive results has remained steady for the past three years, Jennings-Gaines said that “comparing the number of positive tests each year can be misleading” based upon WGFD’s CWD surveillance program, which focuses on different elk and deer herds every year. Further, the number of positive “is proportional to the prevalence of CWD in the particular herd unit surveyed.”

Peak testing occurs between October and November. The majority of the samples collected in 2022 were at hunter check stations or regional offices.

“Chronic wasting disease is a major concern for Game and Fish and we thank hunters who contributed samples from their deer, elk and moose,” said Jennings-Gaines. “These samples are instrumental in helping us better understand the prevalence and distribution of this disease in our state.”