While deer hunters tend to be a safety-conscious bunch, this year they have been asked to be especially observant in an area that has nothing to do with fluorescent orange apparel or basic firearm safety.

Chronic wasting disease, commonly known as CWD, has the potential to wreak havoc on the state’s deer population, and hunters are being asked to help state conservation officials in determining if a threat of the disease exists.

CWD, which affects elk, white-tailed deer and mule deer, was first discovered in Colorado in 1967, and it was long believed that it would remain confined to northeastern Colorado, southeastern Wyoming and western Nebraska. However, in recent years the disease has been documented in Kansas, Minnesota, Montana, New Mexico, Oklahoma, South Dakota, Wisconsin, Wyoming, and Saskatchewan and Alberta, Canada.

One state’s finding, in particular, sent shock waves through the Missouri Department of Conservation, said Jeff Beringer, a wildlife research biologist who works out of the department’s Columbia office.

“When it showed up in Wisconsin, that got a lot of people’s attention,” Beringer said, explaining that transmission of the disease from Colorado to bordering state like Wyoming, Nebraska or Kansas is easily understood. The discovery in Wisconsin, however, was something altogether different.

“I can remember exactly where I was when I heard the news,” Beringer said of the reported case in Wisconsin, wherein three deer were found to have tested positive for CWD on Feb. 28, 2002. “When it (CWD) jumps that far . . . “

Concern is evident in the numbers of deer being tested in the state of Missouri between this year and last. In 2001, 72 deer were tested for the disease, with none showing positive. This year, conservation officials plan to test 6,000 deer as part of a three-year program that will rotate between area counties. In Northeast Missouri, harvested deer in Clark, Scotland, Monroe and Pike counties are being tested this year, with other counties selected at random the next two years.

Hunters checking in deer at a wildlife check-in station in the selected counties are asked to donate the heads of their deer for the testing process. A tissue sample is then taken from the brain of the animal, and the samples in turn are shipped to laboratories at the University of Georgia, Athens, or the University of Wyoming in Laramie, where testing should be completed in the next 3-4 months.

Beringer lauded the cooperation the department has received from hunters so far this year, saying that almost all of the hoped-for 6,000 samples had been received.

“We had great hunter cooperation and that helps us considerably,” he said, adding that hunters and other outdoorsmen are being asked to remain alert for animals showing signs of the disease. If a deer is spotted that shows symptoms of the disease, Beringer said the conservation department will “try and continue to test those sick deer throughout the year. The more people we have out there that are aware of this situation and keeping their eyes open, the better chance we have of finding this disease early.”

CWD, which is presumed to be fatal to deer and elk, belongs to a family of diseases known as transmissible spongiform encephalopathies, which destroy nerve cells in the brain. Over time, the brains of infected animals become sponge-like as more and more nerve cells are affected. Deer or elk showing signs of the disease often appear emaciated and listless, with drooping shoulders and heads, show excessive salivation at the mouth and have excessive thirst.

Beringer said the question of how the disease spreads remains unknown, but one probable cause would include the simple transmission from one affected animal to another in the wild. Beringer noted that another possibility could be an infected captive-bred deer being brought into Missouri from out-of-state.

Lynn Totten, an accounting technician for the Missouri Department of Conservation, estimates that there are 25 big-game hunting preserves in the state that hold deer, and approximately 275 Class 1 Breeders Permits currently issued, which allows individuals or companies to raise, breed and sell deer.

“I would say in captivity there’s over 5,000 (whiteail or mule) deer being held,” Notten said. “It varies because of breeding and selling.”

In addition to those numbers, there are 80 farms holding approximately 2,000 elk in the state.

Missouri currently requires that captive deer or elk transported into the state must come from a herd that has been documented to be CWD-free for a minimum of three years. Those herds are also being tested through a CWD monitoring program.

If CWD does have a silver lining, it may be this: there is no evidence that CWD can spread from infected deer or elk to livestock, and no evidence that the disease is infectious to people.

“There’s some panic out there, especially in other states, but there’s no evidence to suggest that humans can get it,” Beringer said, adding that extensive testing is also being conducted with livestock. “They have cattle living with infected (deer), and I know that cattle have not been infected from living with (infected) deer or elk.”

While Beringer and others may seem overly concerned, consider the following: By Oct. 17 of this year, Wisconsin officials, who first identified the disease in their state in February, had documented a total of 40 cases of CWD. The state now plans to test 50,000 deer in the next few months. Illinois discovered its first case of CWD in a deer shot Oct. 23 in Winnebago County, near the Wisconsin border.

Those wishing for more information on the disease and what steps are underway to combat it can contact their local Missouri Department of Conservation, or visit the department website at www.conservation.state.mo.us.