Although it was considered inevitable, a long-feared disease that affects elk, deer and moose was detected for the first time ever in Southwest Colorado.
Colorado Parks and Wildlife announced this week that 18 deer in an area, roughly from Dove Creek to Wolf Creek Pass, tested positive this year for Chronic Wasting Disease, a fatal neurological disease.
Seventeen of those animals were found in the Cortez area in agricultural areas.
“On the face of it the prevalence looks low, but CWD is 100 percent fatal and we don’t want to see it continue to increase in our herds,” Scott Wait, senior terrestrial biologist for CPW’s Southwest Region, said in a statement.
CWD was first discovered in captive deer in at the Colorado Division of Wildlife’s Foothills Wildlife Research Facility in Fort Collins in the late 1960s, and in 1981, wildlife researchers found it had spread into wild deer populations.
(In 2011, Colorado’s Division of Wildlife merged with the Division of Parks and Outdoor Recreation to become Parks and Wildlife.)
By the 1990s, CWD had spread throughout Colorado and Wyoming. Now, the disease can be found in wild animals throughout 24 states in the Southwest, Midwest and some parts of the East Coast.
It was also discovered in two provinces of Canada.
But because of its relative geographical isolation, herds of elk, deer and moose had not been affected by the disease in Southwest Colorado. That is until it was discovered this year.
CPW required in 2020 all hunters who harvest a deer in the state to test the animal for the disease, which is how it was discovered this year in the region. During the 2020 season, 18 of 1,489 harvested deer tested positive.
“CPW had never done a region-wide check,” said spokesman Joe Lewandowski. “Requiring hunters to bring in deer is the best way to collect enough animals to have an adequate ‘sample size’ of specimens to make a valid determination on prevalence. With CWD advancing around the state we had to do testing in the SW region.
“CPW has been monitoring the prevalence of CWD throughout Colorado for more than 20 years,” the agency said in a statement. ‘This marks the first time that CWD infected deer have been found in this location of Colorado.”
Animals infected with CWD experience drastic weight loss, stumbling, listlessness and other neurological symptoms, according to the Centers for Disease Control and Prevention.
Some animals, the CDC said, can die without ever developing symptoms of the disease.
“CWD is fatal to animals and there are no treatments or vaccines,” the center said.
A 2016 study from the University of Wyoming found deer populations affected by CWD declined 10% a year from 2003 to 2010. At that rate, the study determined the animal could become extinct in less than 50 years.
One of the researchers, University of Wyoming Ph.D. graduate David Edmunds, said at the time the decline was caused directly by CWD lowering the annual survival of female deer, which has the biggest impact on population growth rates.
“This was because CWD-positive deer died both directly from the disease and were more likely to be killed by hunters than CWD-negative deer,” Edmunds said in the university’s statement about the research.
The issue for wildlife managers, however, is there are no proven control or prevention strategies to combat the disease.
In some instances, CPW will increase the number of tags to hunt deer in an area, rationalizing that harvesting more animals can reduce the spread and number of infected animals.
CPW said in a statement wildlife managers in Southwest Colorado are evaluating how many hunting tags to issue for the region in 2021.
Big game herds are considered “above the herd management objectives” in the area, CPW said. West of Durango, hunting tags will be increased to meet population objectives and also prevent the spread of CWD.
East of Durango, the deer herd is within its objective population range, though it is unclear if hunting tags will be increased to help stop the spread of the disease.
To date, there is no strong evidence the disease can spread to humans, though people are encouraged not to eat the meat of animals that test positive, CPW said.
Lewandowski said CPW will continue to monitor the situation into the future and voluntary CWD testing for deer will be available to hunters for the 2021 season for $25. CPW will require mandatory testing of elk harvested during specific limited rifle seasons this fall.
“There will be no charge for those tests and hunters who draw tags for those seasons will be informed of testing procedures next summer,” he said. “CWD has never been found in elk in this area of Colorado.”