Friday, November 21, 2008

Elk disease moves West

Discovery of neurological disease in western Wyoming worries biologists

Express Staff Writer

Wintering elk feed at the Idaho Department of Fish and Game’s Bullwhacker feed site midway up the Warm Springs Creek drainage southeast of Ketchum in this photo taken last winter. Idaho biologists will have to be on heightened alert after chronic wasting disease was found in a moose just over the border in Wyoming last month. Photo by Willy Cook

The discovery last month of a three-year-old female moose just over the border in western Wyoming that tested positive for chronic wasting disease has raised the stakes here in Idaho.

The transmissible neurological disease is a fatal ailment in deer, elk and moose that affects the brain, causing weight loss, abnormal behavior and eventually death. Other signs include loss of body condition, excessive drooling and drooping ears and head.

Though it's similar to mad cow disease in cattle, there is no evidence that chronic wasting disease has any human-health implications.

Perhaps most alarming about the discovery of the infected moose was its presence in an area where the disease was not yet thought to be present. The moose was found on the west side of the Continental Divide in the Star Valley area, which is south of Alpine, Wyo., a news release from Wyoming Game and Fish states.

Its discovery near the town of Bedford means the moose was no more than 10 to 15 miles from the Idaho border.

"This finding was a very big surprise," said Wyoming Game and Fish Department Wildlife Disease Specialist Hank Edwards.

Previously, chronic wasting disease had only been thought to exist farther east in Wyoming on the opposite side of the Continental Divide. The disease is also known to be present in wild deer and elk herds in Colorado, Utah, New Mexico, South Dakota, Nebraska, Kansas, Wisconsin, Illinois, New York, West Virginia and Alberta and Saskatchewan in Canada.

So far, the 1,000 samples the Idaho Department of Fish and Game takes from big game herds each year have failed to detect the troubling disease.

Though it has been found in deer and elk in many parts of Wyoming and other states, chronic wasting disease is considered extremely rare in moose. According to Wyoming Game and Fish, only three other wild moose in North America have tested positive for the disease, all of them in Colorado.

The agency stated that the inflicted moose did not show any of the clinical signs of chronic wasting disease, except that it was unable stand up.

In light of the discovery, Wyoming biologists will step up their testing efforts in the western half of the state, particularly in the Star Valley area. Officials have noted that the discovery suggests that other deer, elk or moose in the area may be infected, too.

"We will immediately begin to gear up our ... surveillance in the Star Valley," said Tim Fuchs, Wyoming Game and Fish wildlife supervisor for the Jackson Region.

Wyoming Game and Fish personnel collect and analyze more than 4,000 samples each year in areas throughout the state.

So what does the Star Valley discovery mean for big game herds in Idaho?

In eastern Idaho, the discovery will likely mean an even greater emphasis on testing. Only dead animals can be tested for chronic wasting disease, said Randy Smith, wildlife manager for Idaho Department of Fish and Game's Magic Valley Region, which covers the Wood River Valley.

Smith said about 100 animals—mainly mule deer and elk—are tested for the disease each year in the Magic Valley Region. He said most of those are tested in the north half of the region, primarily near Fairfield and in the Wood River Valley.

Smith said that for the time being, eastern Idaho will remain Fish and Game's top priority due to its proximity to Wyoming and Utah, which has also seen positive tests for the disease in its wild big game herds.

"We have a lot more surveillance in eastern Idaho," he said.

Smith said most testing is done on big game animals harvested by hunters. For mule deer, the testing is done on lymph nodes taken from their neck area. On elk, the testing is done on a small part of their spinal cords near where it connects with the brain.

Under the leadership of the Fish and Game's top wildlife veterinarian, Mark Drew, Idaho has developed a plan to address chronic wasting disease if it is discovered in any of the state's big game herds, Smith said. He said infected herds would be targeted with higher hunter harvest levels.

Many in the conservation community have suggested that the artificial feeding of big game animals—especially prevalent in Wyoming—may be leading to increased levels of chronic wasting disease.

"Diseases spread much more easily when animals are in closer contact," Smith said.

Still, he said that to his knowledge, no artificial feed sites have ever been closed due to the presence of the disease.

Nevertheless, he said the discovery of chronic wasting disease will put Idaho big game managers on a heightened alert in regards to artificial feeding. Locally, Fish and Game operates just one feeding area for elk midway up the Warm Springs Creek drainage in an area called the Bullwhacker feed site.

Smith said the possibility that disease may be present in big game herds means sites like Bullwhacker should be watched with care.

However, he said the presence of chronic wasting disease in big game herds doesn't necessarily spell disaster. In Colorado, herds continue to do well.

"They have some fantastic deer hunting," he said.

According to Wyoming Game and Fish Director Steve Ferrell, no methods have been discovered that have proven effective in stopping the expansion of chronic wasting disease.

"Recent research in Wisconsin and Colorado has shown us that large-scale culling of animals is ineffective in stopping the spread of the disease or reducing its prevalence," Ferrell said.

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