Results from tests of 403 wild elk and deer taken by Montana hunters and wildlife biologists last fall show none of the animals were exposed to Chronic Wasting Disease (CWD), an illness that causes weight loss and other symptoms which result in death in elk and deer.
"It's a great relief that this extensive effort hasn't turned up CWD in Montana's wild elk and deer but we have more work to do to ensure that we keep this deadly disease out of the wild," said Don Childress, administrator of FWP's wildlife division in Helena.
The disease, which has become a concern to western states wildlife managers, has occurred in four captive wildlife research facilities in northern Colorado and one in southeastern Wyoming. CWD also has been confirmed in free-ranging, wild deer and elk in some counties in northeastern Colorado and southeastern Wyoming. Federal and State and Provincial animal health authorities have identified CWD in captive elk at game farms in Colorado, Oklahoma, Nebraska, South Dakota, and Saskatchewan, Canada. CWD does not appear to be present in Montana, but in June 1998 and again in June 1999 the Montana Department of Livestock notified FWP that a game farm elk shipped from Montana to Oklahoma were confirmed to have CWD. The origin and the mode of transmission of CWD is unknown.
Because the disease cannot be detected in living animals, brain-tissue samples were collected from the heads of 620 deer and elk taken last fall by hunters and wildlife biologists from across Montana. The samples were examined by the Montana Department of Livestock's veterinary pathologist for the microscopic lesions that could suggest the presence of CWD, a disease similar to other forms of "transmissible spongiform encephalopathies," commonly referred to as scrapie in sheep, and mad cow disease in cattle.
Tissues from 217 of the samples taken from Montana elk and deer last fall were determined to be unsuitable for testing, but brain tissue from 403 animals were further tested via a special staining process and all tested negative for CWD.
"Although CWD hasn't been found in Montana's wild deer or elk we will continue our surveillance efforts, expand the geographic distribution of surveys and increase the number of wild deer and elk tested," Childress said.
In November 1998, FWP and the Montana Department of Livestock agreed carry out a plan to determine if CWD is present in Montana. Measures include testing of wild elk and deer and game farm animals and the adoption of rules by the Department of Livestock to test and regulate the importation of game farm animals to reduce the risk of introducing CWD into Montana.
Under the 1998 agreement, FWP will again be working at selected hunter game-check stations statewide this fall to collect deer and elk heads from harvested animals. "We'll be asking hunters to voluntarily donate the head from deer and elk that are 1_ years old and older," said Keith Aune, FWP's wildlife laboratory supervisor. "When the heads are collected the carcass will be specially tagged to alert our game wardens that the hunter has participated in the CWD survey," Aune said. "Hunter cooperation and participation will be essential to the success of this wildlife disease surveillance effort."
Aune also noted that FWP biologists and wardens will conduct "targeted surveillance" of elk and deer that appear to display clinical symptoms suggestive of CWD--emaciated animals that appear listless, with blank facial expressions, excessive salivation, lowered heads and, in some cases, hyperexcitability and nervousness. Aune encouraged hunters who see animals with any of these symptoms to contact the nearest FWP office.