Chronic Wasting Disease
Chronic Wasting Disease (CWD) is a transmissible spongiform encephalopathy (TSE) disease that affects cervids. The causative agent of TSE diseases are prions, or proteins that fold abnormally and become infective and ultimately fatal. CWD was first detected in the 1960s in mule deer housed in research facilities in Colorado. By the 1980s, it was detected in free-ranging elk. To date, chronic wasting disease has been detected in 30 states in the U.S. and several Canadian provinces. As the name implies, signs of CWD include chronic weight loss leading to emaciation, abnormal behavior, difficulty walking or standing, and affected animals often have poor quality coats. SCWDS conducts testing for CWD in cervid samples submitted from members agencies throughout the southeastern United States. Since CWD can have an incubation period of up to two years, early detection of cases is essential to limiting the spread of the disease.
If you encounter wild cervids exhibiting signs consistent with CWD infection or for more information, please contact your state wildlife agency.
Hemorrhagic Disease
Hemorrhagic disease (HD) is a major disease complex of wild ruminants in North America. It consists of the Orbiviruses epizootic hemorrhagic disease virus (EHDV) and Bluetongue virus (BTV) which are transmitted by the insect genus Culicoides, commonly known as biting midges. There are two main forms of HD: acute and chronic disease. The acute form rapidly progresses and lethargy, lameness, hemorrhaging of oral, thoracic, and gastrointestinal systems can lead to heavy mortalities. The chronic form typically presents as lameness, sloughing of hoof walls that can lead to secondary infections, and emaciation due to rumen ulcers and loss of rumen papillae which impedes digestion and absorption of nutrients. There is a seasonality of HD outbreaks corresponding with the emergence of Culicodes midges in early spring through fall, but regional patterns can vary tremendously: infrequent but severe mortality can occur in more northern latitudes while frequent, mild to asymptomatic infections are common in more southern regions. In areas where mortality is severe, HD can drastically affect population levels, but in areas where the chronic form is more prevalent, population-level impacts are likely minimal. SCWDS conducts testing for HD in cervid samples submitted from members agencies throughout the southeastern United States. Historically, two serovars of EHDV (EHDV-1 , 2) and five serovars of BTV (2, 10, 11, 13, 17) were predominant in North America; however, recent diagnostic serology testing has determined that multiple EHDV and BTV serovars are associated with HD outbreaks in wild cervids, particularly EHDV-6.
If you notice a wild cervid with signs consistent with HD, please notify your state wildlife agency.
