Chronic wasting disease (CWD) is classified as a neurological disease found in animals including North American Elk, Red deer, Mule deer, Black-tailed deer, White-tailed deer, Sika deer, and moose; which are also referred to as cervids. Cervids are any member of the deer family, Cervidae, and is comprised of deer, caribou, elk, and moose and are characterized by the bearing of antlers in the male or in some cases both male and female of the species.
What is Chronic Wasting Disease? Chronic wasting disease (CWD) belongs to a family of diseases that are described as transmissible spongiform encephalopathies (TSE) or prion disease. A prion is an infectious agent that is composed entirely of protein material called PrP (short for prion protein) that once infected can lead to a disease that is similar to a viral infection. The word prion is derived from the words protein and infection. Prion is used as the shortened term for proteinaceous infections particle.
CWD is fatal in cervids but there is no evidence suggesting that CWD can be transmitted to humans. The disease attacks the nervous system of its host infecting the brain, spinal cord, eyes, spleen and lymph nodes but traces of the disease can also be found throughout the entire animal. Once established in a population, eradication is thought to be impossible.
How does the disease spread? Chronic wasting disease can spread through the natural movements of the herd of infected animals. Cervids can become infected through animal to animal contact along with contact through a contaminated environment. Infection can be spread through saliva, urine, blood, faces or decomposition of an infected animal. The environment can remain stable and continue to infect animals for years. There is no known treatment or vaccine for CWD.
What are the symptoms of CWD? It is impossible to diagnose CWD by the symptoms alone and a positive diagnosis of the disease can only be made by post-mortem testing of the brain or lymph nodes in the throat. Symptoms of infection include emaciation, excessive salivation, difficulty swallowing, excessive thirst, lack of muscle control and excessive urination.
Since there are no specific management strategies in place to minimize the risk of infection once an environment has become infected this essentially makes eradication impossible; especially in areas that have been established for a long period of time before detection. Both the Texas Parks and Wildlife Department (TPWD) and the Texas Animal Health Commission (TAHC) are working in conjunction with ranch owners and hunters to submit harvested mule deer for sampling as part of an enhanced, statewide monitoring effort to detect Chronic Wasting Disease.
There are currently plans for mandatory check stations to be set up inside CWD containment areas including Husdpeth, Culberson and El Paso counties. Hunters taking deer within the containment zone during the 2015-16 mule deer hunting season are required to submit the unfrozen deer head within 24 hours of harvesting. To date, over 800 tissue samples have been collected for testing during the past three hunting seasons and fortunately, CWD has not been found in mule deer located outside of the Hueco Mountain area.