Chronic wasting disease containment demands vigilance, common sense
A positive case of chronic wasting disease was recently verified in a captive white-tailed deer in Medina County, and hunters are advised to learn precautionary measures.
"Chronic Wasting Disease is a condition that affects the nervous system of deer, elk and moose," said Dr. John Tomecek, Texas A&M AgriLife Extension Service wildlife specialist at San Angelo. "It is similar to diseases such as scrapie in sheep and goats, and bovine spongiform encephalopathy or BSE in cattle. There is no evidence chronic wasting disease can be transmitted to sheep, goats, cattle or humans."
"Chronic wasting disease was reported in Far West Texas in 2012, which was the first instance in the state in wild mule deer until the Medina County confirmation reported by the Texas Parks and Wildlife Department and the Texas Animal Health Commission on July 1, 2015."
Tomecek said the precise origin where chronic wasting disease developed is unknown, but the condition was first detected in 1967 in a captive research mule deer herd in Colorado. Since then it has been detected in 22 U.S. states and two Canadian provinces.
"As its name suggests, chronic wasting disease causes weight loss and degraded body condition, abnormal behavior and ultimately death of the animal," Tomecek said. "Infected animals may drink and urinate excessively and exhibit symptoms ranging from repetitive movement to sluggishness or hyperactivity to standing 'spraddle-legged' with a blank expression and head held low."
There is no vaccination to guard against it, and once infected there is no treatment for animals with the disease, so prevention is the only solution, he said.
"The most common prevention techniques practiced in other states include removing infected animals from the population and discouraging high-density deer scenarios coupled with intensive sampling for early disease detection. It should be noted that the Texas Parks and Wildlife Department has been monitoring our state's deer for the disease since 2002."
Among the over 33,000 deer tested, no white-tailed deer tested positive until the recent occurrence near Medina, he said.
Tomecek said deer hunters have always been important in deer management to balance population size, while maintaining healthy habitat.
"High deer densities compromise habitat and contribute to easier transmission for a variety of pathogens," he said. "Common sense should prevail, and a diseased animal, whether it might have chronic wasting disease or some other health issue, should not be consumed.
"Although there is no evidence of human health risks, experts advise those hunting in known chronic wasting disease areas to completely process healthy-looking harvested animals to include removing the bones and any brain, spinal, tonsil, spleen or lymph node tissues," he said. "Disposing of these organs in a location where other susceptible species will not encounter them helps limit the spread of the disease."
"Some people have expressed concern about the potential of chronic wasting disease to negatively impact deer populations in Texas. While that is a possibility, states where CWD is prevalent still have large, healthy deer populations that provide excellent hunting. Early prevention and action are paramount in controlling many diseases, including this one," he said. "Therefore Texans should focus on remaining vigilant by immediately reporting any deer they suspect may be diseased to the Texas Parks and Wildlife Department."
Tomecek added, "The key message is to enjoy the outdoors, while paying attention for animals showing signs of distress."