A moose in Colorado recently tested positive for chronic wasting disease, the first of the species known to do so in the wild, but Alaska's wildlife experts aren't worried the deadly disease will infect Alaska's ungulates any time soon.

And if it does, they will know it sooner rather than later.

The state Department of Fish and Game has been testing deer, elk and moose in Alaska for chronic wasting disease for the past two years. So far there has been no sign of the fatal neurological disorder that has spread among deer and elk populations in the Lower 48.

At last report, the state had tested 531 Sitka blacktail deer, 96 moose, 24 Roosevelt elk and one caribou for CWD.

A moose killed by an archer in northern Colorado on Sept. 10 tested positive for CWD, the first time the disease has been found in the largest members of the deer family.

Chronic wasting disease is a fatal and transmissible brain disease similar to mad cow disease that had previously only been found in deer and elk in the wild. It was first discovered in mule deer in Colorado in 1967 and scientists don't know where it came from or how it is transmitted.

"It's sort of like something out of the 'X-Files,'" said Larry Van Daele, a longtime state wildlife biologist in Kodiak. "It messes up the proteins in the brain and eats holes in the brain. We don't know how it spreads but it spreads rapidly."

The disease has been found in deer and elk in Colorado, Wyoming and Nebraska; and in deer in Utah, New Mexico, South Dakota, Wisconsin, Illinois, New York and West Virginia, and in the Canadian provinces of Saskatchewan and Alberta.

Scientists have found no evidence the disease can be transmitted to humans, but hunters in states where CWD has been documented are advised not to eat meat from infected animals and to avoid eating nervous system tissue from deer and elk.

Veterinarians in Alaska have been testing Sitka blacktail deer taken by hunters on Kodiak Island for the past two years and this year are doing the same for elk and deer in Southeast. Biologists are collecting samples from deer and elk heads donated by hunters in Juneau and Ketchikan.

Samples are collected from the animals' brains, lymph nodes and tonsils, which are then sent to Colorado State University to be tested. Testing must be done in a U.S.D.A. approved laboratory and there is not one in Alaska.

With over 500 deer samples in the bank, state wildlife veterinarian Kimberlee Beckmen with Fish and Game in Fairbanks said the department is "99 percent confident" the disease has not infected any deer on Kodiak Island.

"That's a big enough sample size that if CWD was present in the population we're 99 percent confident we'd detect it," she said.

"Our CWD surveillance program is concentrated on Sitka blacktail deer and elk because they're more closely related to mule deer and Rocky Mountain elk, where the disease originated," said Beckmen, noting that Sitka blacktail deer are a sub-species of mule deer. "We didn't concentrate on moose or caribou because they never had it before."

The state is testing moose for CWD on a smaller scale. Beckmen performs necropsies on any moose that is reported dead as a result of starvation or an unknown cause, or moose that display any signs of CWD prior to death. Symptoms include listlessness, repetitive walking in set patterns, lowering of the head or having a blank facial expression.

"Any moose that is necropsied is tested," said Beckmen.

It's not reasonable to ask moose hunters to bring in the heads of animals for testing, considering how big they are, she said.

Besides, wildlife officials are more worried about Alaska's elk and deer populations becoming infected with CWD than moose and caribou. Moose in Colorado were exposed to CWD for more than 30 years before the recent positive test, Beckmen said. Almost 300 moose have been tested in Colorado since 2002.

Researchers at the University of Wyoming were able to intentionally infect a captive moose with CWD, but it took several tries and required feeding the moose a "massive dose" of infected mule deer brain, said Beckmen.

"Moose don't seem to be highly susceptible," she said. "It was very difficult to get it into moose even experimentally."

Perhaps the biggest CWD risk posed to Alaska's moose or caribou comes from private elk farms, which have been associated with the disease in several instances in the Lower 48.

One of the reasons veterinarians are looking for the disease on Kodiak is that there is a robust deer population and there is a commercial elk farm on the island, said Van Daele. It's possible some of the elk on the farm may have come from areas in the Lower 48 that were exposed to CWD, he said.

While the Department of Environmental Conservation initiated a voluntary program to have private elk ranches tested for CWD, Alaska's elk ranchers aren't required to have animals tested. Only a handful of elk have been tested on Alaska's 12 elk farms, Beckmen said.

"None of the 12 elk farms in Alaska are CWD-free certified yet," she said.

As a result, the state has banned the importation of domestic elk.

As thanks for bringing in deer and elk heads to be tested for CWD, hunters get a ballcap that features an elk silhouetted against the state of Alaska with the words, "Alaska CWD Surveillance" emblazoned on it.

"Alaska hunters being what they are, if you give them a baseball hat they'll do anything for you," Van Daele quipped.

The state spent $53,000 on CWD testing last year and got the same amount for this year's testing program. The money comes from the U.S. Department of Agriculture.

Almost half of the $53,000 goes to laboratory testing, Beckman said. The rest pays for a veterinarian in Kodiak to gather samples from deer brought in by hunters, as well as sampling supplies and training workshops. It costs $20 per animal to test.

Anything the state can do to ensure CWD doesn't spread to Alaska's wildlife populations is worth it, he said.

"We want to be especially cautious in Alaska, where we do have a pristine wildlife population," said Van Daele. "We've seen no evidence whatsoever of CWD but we're still going to maintain a surveillance program."

News-Miner staff writer Tim Mowry can be reached at 459-7587 or tmowry@newsminer.com.