By Chris Nix, Wildlife Biologist, Division of Wildlife and Freshwater Fisheries
Chronic Wasting Disease (CWD) is a contagious neurological disease affecting the central nervous system of captive and free-ranging mule deer, white-tailed deer, moose, and Rocky Mountain elk throughout various locations in North America. This is a fatal and untreatable disease belonging to a group of diseases known as transmissible spongiform encephalopathies and is similar to mad cow disease in cattle and scrapie in sheep.
CWD can reduce the growth and size of wild deer and elk in areas where populations are high, and is of increasing concern for wildlife managers across North America. The disease had been long thought to be limited in the wild to a relatively small area in northeastern Colorado, southeastern Wyoming and southwestern Nebraska, but has recently been found in several new areas across the North American continent.
To date there has been no case of CWD detected in Alabama or any other southeastern state. Although that is good news, it is still of upmost importance to prohibit the spread of CWD.
It is thought that a major method by which CWD is spread is through the movement of live animals, most often for game farming or breeding operations. Fortunately, the importation of any deer into Alabama has been prohibited since 1973. It is critical that this importation ban is strictly followed. Any suspected violations should be reported to the nearest Wildlife and Freshwater Fisheries office immediately.
In Alabama, annual samples from deer harvested throughout the state are tested for CWD. This survey began during the 2001-2002 hunting season and continues today. Collectively, throughout this study approximately 4,100 deer have been tested for CWD. All tests were negative.
CWD is indicated by a variety of physical signs. Because the brain is the primary organ affected by the disease, infected animals begin to lose bodily functions and display abnormal behavior. In early stages of infection, animals do not show any symptoms. The incubation period can range from about 12-18 months up to 3-5 years. In later stages, infected animals begin to display abnormal behavior such as staggering or standing with very poor posture. Animals may have an exaggerated wide posture or carry the head and ears lowered, and may drool. Infected animals become emaciated (thus the name “wasting disease”) and appear in very poor body condition. Clinical symptoms are typically not seen in deer younger than 18 months of age. CWD symptoms may also be characteristic of diseases other than CWD (e.g. deer with bacterial brain abscesses or chronic hemorrhagic disease).
If a suspicious animal is encountered, document the location of the animal and immediately contact the Wildlife and Freshwater Fisheries office nearest you. For more information on CWD, contact Chris Nix, Wildlife Biologist, Alabama Department of Conservation and Natural Resources, Division of Wildlife and Freshwater Fisheries, 30571 Five Rivers Blvd., Spanish Fort, AL 36527; 251-626-5474.