With breaking news this week that Wisconsin hunters will be able to have an additional 200,000 deer tested for CWD (chronic wasting disease) under an agreement reached between the state and the U.S. Department of Agriculture, the state will have available an extremely high intensity program to determine how widespread this fatal brain disease is in Wisconsin’s whitetail deer herd.
According to a recent DNR news bulletin pertaining to CWD and special October T-Zone deer hunts, wildlife biologists, veterinarians and epidemiologists have worked hard to define the extent of CWD in deer and elk in Wisconsin and to make a plan to eradicate it.
“There is much to be learned about CWD,” said Tom Hauge, chief of the Department of Natural Resource’s wildlife management bureau.
“Over the past months, members of the state’s CWD Task Force have formulated an ambitious plan to test 40,000 to 50,000 hunter-harvested deer for CWD this fall. The results will answer the question on exactly where the disease exists in Wisconsin, and, more importantly, where it doesn’t exist. The expansive sampling plan will determine with a high degree of assurance the presence or absence of the disease for every county in the state.”
The testing capability will be in addition to the 50,00 deer the DNR had planned to test under its original plan. Hauge explained that about 50,000 hunters whose deer are sampled will get a free CWD test on their kill. That number alone is over three times that of any other state offering free CWD tests.
Sampling for CWD testing will take place primarily during the October T-Zone and November firearm deer hunts. Experts are stressing that the sampling is for surveillance of CWD in deer and not a food safety test. The CWD disease-causing agent has not been documented to affect people, and it never has been found in deer muscle tissue.
“There is a common misconception that a CWD test is a food safety test,” notes DNR wildlife veterinarian Julie Langenberg. “The ‘gold-standard’ immunohistochemical test and, for that matter, all the newer tests still in development, only show whether the disease-causing agent is present at a detectable level in the tissue being tested, at the time it is tested.”
“It is possible that CWD prions could be present in an animal at levels below those detectable by the test being used; a specific example would be a deer which was infected recently. A negative test result in this case may provide a false sense of security. However, we do know the risk of any deer in Wisconsin having CWD is very, very low, and there is no evidence that CWD can affect people,” she said.
The state plan will use what it calls a “three-tiered” approach for CWD testing on deer. The most intensive sampling will occur in the CWD intensive harvest zone in southern Wisconsin (first tier) where every harvested deer yielding a testable sample will be tested.
In the second tier (an area with a 40-mile radius from the infection area), 500 deer over one year of age from each deer management unit within that area will be tested. In the third tier, 500 deer will be tested from the remaining counties in the state.
In addition, hunters will be able to bring their deer to a participating veterinarian to have brain stem tissue sampled for the presence of CWD, or they may submit a sample for testing by extracting the brain stem themselves and mailing it to a federal laboratory. A fee will be charged in either case.
Hauge stated that the state’s CWD testing will be the most intensive effort ever undertaken for a wildlife species. It will require 800 to 1,000 persons to register the deer, remove the heads from the dead animals, collect tissue and transport the samples.
Deer heads will be collected at county collection stations and then be transported to regional processing centers where brain stem and lymph node tissue samples will be taken for shipping to a laboratory.
Outside of the deer eradication zone in southern Wisconsin, hunters will be asked to volunteer heads from adult deer for sampling.
Hunters whose deer are sampled will be given instructions on how to find out the test results from their deer.
While the 50,000 deer to be tested by the state during the 2002-2003 deer hunts may be a small percentage (about 12 percent) of Wisconsin’s annual kill, that number would be nearly the entire kill for the state of Colorado. If 200,000 more animals are tested, that could bring the testing rate to over 50 percent.
To find out where collection sites for testing CWD in deer taken during the October T-Zone hunt in Northeastern Wisconsin, call your local DNR office or click onto the DNR’s website (www.dnr.state.wi.us) and then click onto the “Chronic Wasting Disease” link.