Wisconsin’s battle against Chronic Wasting Disease will continue into 2005 as the Wisconsin Department of Agriculture announced the first recorded case of the new year last week.
The disclosure comes after a white-tailed deer in Crawford County tested positive for the disease after it was found dead of apparent respiratory failure.
As a one of the 40-member herd belonging to Curtis Christensen, the deer was enrolled in the state’s CWD monitoring plan. The remaining deer in the herd have been quarantined to prevent the spread of the disease, according to a release.
There are currently 20 deer herds in Wisconsin that are quarantined, half of which are farm-raised. Since CWD was first detected in Wisconsin in February 2002, 28 of approximately 10,000 farm-raised animals from seven farms tested CWD positive.
Of the 56,000 deer samples submitted by hunters for testing over the last three years, 326 CWD positive animals have been identified, according to Department of Natural Resources Bureau of Wildlife Management Director Tom Hauge.
“This enormous accomplishment would not have been possible without the cooperation of hunters who surrendered the heads of their deer at collection stations during regular and extended fall gun deer seasons and special summer hunts,” Hauge said.
CWD is a fatal disease which affects the brain and spinal cord of cervids, a family of animals which includes white and black tailed deer, mule deer and elk. CWD is part of a group of diseases that also includes Mad Cow Disease in cattle and Creutzfeld-Jakob disease in humans, according to the Department of Agriculture website.
It is caused by improperly folded proteins called prions that are found in the central nervous system. These abnormal proteins accumulate in nervous tissue, forming sponge-like lesions. There is no cure for CWD.
The only way to test for the disease is to examine the animal’s brain for the presence of sponge-like lesions. Due to the recent appearance of the disease and the lack of a preclinical diagnosis, much remains unknown about CWD.
There is no definitive answer as to how CWD is transmitted, according to Dr. Judd Aiken, professor of animal health and biomedical sciences.
“That sometimes gets interpreted as ‘we don’t know that it does get transmitted,’ but it very clearly is a contagious disease,” Aiken said. “As to how it’s being transmitted, there’s probably some animal to animal passage.”
Aiken said there have also been documented cases of infectious agents in the soil, but added that researches still do not know.
The University of Wisconsin has proven to be a bastion of research on the topic and many avenues of study are being examined on this campus.
“You’ve got a disease that not a lot is known about. We don’t know how it’s transmitted, we don’t have an easy way of diagnosing it — it stays out in the environment so you have the potential to transmit CWD to other species.”
Aiken added there are many unknowns with CWD and, consequently, there are many avenues of research.
