CWD November 2002
Chronic wasting disease (CWD) is receiving attention in several states and in Canada. The disease, which affects elk, mule deer and white-tailed deer, was first observed in Colorado in 1967 and, until recently, was thought to be confined to north-eastern Colorado, southeastern Wyoming and western Nebraska. Since the late 1990s, however, chronic wasting disease, more familiarly known as CWD, has been found in deer and elk in 10 states and two Canadian provinces.
As part of its ongoing monitoring of the health of the state's wildlife, the Department of Conservation last year began testing Missouri deer for this disease. The 72 deer tested included any obviously sick or emaciated deer reported to conservation agents or offices. No CWD was found in Missouri.
The Missouri Department of Agriculture also tested elk brought into Missouri from an infected Colorado captive herd. None of the elk tested had CWD.
Because the disease has been found in other states, the Conservation Department is increasing its efforts to monitor Missouri deer for chronic wasting disease. This fall, the Department will test 6,000 deer - 200 from each of 30 randomly selected counties. The remaining counties will be sampled in 2003 and 2004. The sampling is designed to detect CWD, even if it exists in a small percentage of the state's deer herd.
Hunters who bring deer to check stations in selected counties during the November firearms deer season will be asked to voluntarily donate the heads of their deer for later testing by a federally approved laboratory. Removing the deer heads will only take a few minutes. Hunters will be able to keep the antlers from bucks. Testing, which involves examining the animal's brain, will be completed in about three to four months. Overall results will be posted on the Conservation Department's website for anyone interested in the sampling effort.
Chronic wasting disease belongs to a class of diseases known as transmissible spongiform encephalopathies (TSEs). Scrapie, which affects sheep and has been documented since the 1700s, is probably the most familiar of these diseases. Like other TSEs, CWD destroys nerve cells. The brain becomes sponge-like over time as nerve cells are affected. The disease is presumed to be fatal to deer and elk. Symptoms appearing during later stages of chronic wasting disease include a listless posture (with heads and ears drooping), weight loss, excessive thirst and salivation and frequent urination.
It's not yet clear how CWD