5 March 2015 - Ultimately fatal, chronic wasting disease affects animals' brains and nerve tissue Southwestern Montana is no stranger to wildlife diseases, but so far, it hasn’t had to confront chronic wasting disease, a scourge that continues to make headlines elsewhere.

That might change in a few years.
On Monday, Wyoming Wildlife Advocates released a map of Wyoming showing the rapid spread of chronic wasting disease over the past decade. It also illustrates that fewer than 40 miles separate Yellowstone National Park and Wyoming’s elk feed grounds from known infected areas.
To slow or halt the march of CWD, conservationists are lobbying to close Wyoming’s elk feedlots, including one at the National Elk Refuge in Jackson Hole that feeds almost 8,400 elk during the winter.
“If we want to minimize the effect of CWD on the greater Yellowstone herds, the time to act is now. Failure to do so risks very real damage not only to wildlife but also to the tourism- and wildlife-dependent economies of the area,” said WWA executive director Kent Nelson.
The group based the map on 14 years of data gathered by the Wyoming Game and Fish Department and other research projects.
Chronic wasting disease is caused by a protein that attacks the nervous systems of deer, elk and moose. Similar to mad cow disease, it results in a slow deterioration of the brain and other nerve tissue so it is eventually fatal.
It doesn’t affect livestock or people as long as they don’t consume the brain or certain other organs of infected wildlife. But it has caused havoc with wildlife populations in states in the Midwest and Mid-Atlantic regions.
In the wild, the disease’s protein doesn’t degrade quickly, so it is very difficult to eliminate once it has moved into an area.
In the Rocky Mountain region, that area includes New Mexico, Colorado, Utah and an increasing portion of Wyoming. Between 2001 and 2014, CWD spread across Wyoming at a rate of 1.8 million acres a year — or just a bit more than the acreage of Gallatin County per year.
Prior to 2000, the disease affected animals only in 8 million acres of the southeastern corner of Wyoming around Cheyenne up north to Casper.
Over the next seven years, it rapidly spread north and west, covering an additional 15 million acres.
Between 2007 and 2014, the spread slowed slightly but added 10 million acres, inching steadily toward Yellowstone and Grand Teton national parks.
Biologists and conservationists are concerned about what will happen when CWD appears in the two dozen elk feedlots of western Wyoming.
The disease is transmitted between animals through their saliva, urine and possibly their feces and bodily fluids. So areas where animals are concentrated, such as game farms or feedlots, present more risk for spreading the disease.
Some believe the feedlots have contributed to the transmission of brucellosis in elk.
CWD regularly sweeps through game farms in the Midwest and Alberta and Saskatchewan, and now it’s happening more in the West.
A month ago, the Utah Department of Agriculture found a bull elk infected with CDW in a Utah game farm. More than 60 elk, along with 20 wild deer and two moose in the same area, had to be slaughtered.
The owner of the farm owns another in Idaho, where legislators are trying to lift a ban on importing elk into the state.
In Montana, the only elk to test positive for CWD was on a Bitterroot Valley game farm before Montana banned game farms, said Howard Burt, Montana Fish, Wildlife & Parks Region 3 wildlife chief.
Montana started monitoring for CWD in 1998, testing road kill or culling animals with abnormal behavior.
That ramped up around 2010, when FWP received funding to sample game brought in by hunters. That funding ran out in 2013, but Burt said FWP has received money to watch for animals crossing the Canadian border, where more deer migrate between seasonal habitat.
None of the almost 850 animals tested have been positive, but Burt said CWD could still be out there.
“One of the benefits we have in Montana is we don’t have the densities of whitetailed deer like they do in the Midwest,” Burt said. “It’s a bit of a mystery on how to stop it once it’s there. But Colorado has had it since the ‘60s and it still has healthy populations of deer and elk.”