CWD causes irreversible damage to brain tissues in affected animals and ultimately leads to death. CWD is one of a group of diseases known as Transmissable Spongiform Ecephalopathies (TSEs). Other TSEs include Scrapie in sheep, Mad Cow Disease in cattle, and Creuzfeldt Jacob Disease in humans.

Chronic Wasting Disease is known to occur in mule deer, elk, and whitetailed deer, although other cervids such as red deer, fallow deer, sika deer as well as moose, and caribou may also be susceptible. CWD is thought to be caused by an infectious protein called a prion that upon entering the body causes the host's normal proteins to take on a diseased form. These prions accumulate in the brain and spinal cords, as well as lymph nodes, spleen, eye tissues, bone marrow, saliva, feces and urine in diseased deer.

IFW will conduct a statewide sampling system in an effort to detect CWD in Maine. The sampling will involve the collecting of up to 670 deer heads from hunter harvested or road killed deer. Lymph nodes, tonsils and the brain stem will be taken from each sample, and later tested at a national facility. Results will not be available for several months due the number of deer being tested nationwide.

This is not the first time that deer have been sampled in Maine for Chronic Wasting Diseason. In 2000, 299 deer from Maine were sampled for Chronic Wasting Disease and they all tested negative. The tests were administered in the winter of 2000 on deer that were collected in the Rangeley area during the 1999 deer hunting season by the Department of Agriculture. The tests were conducted by the U.S. Department of Agriculture at the National Veterinary Services Laboratories in Ames, Iowa.

The earlier sampling in Maine was done in response to a request from the Center for Disease Control. The CDC hade conducted extensive interviews with family members of young adults who have been affected with Creutzfeldt Jakob Disease, looking for any common factor. Three affected young adults had consumed deer meat at some point during their lives. The reason for studying deer from western Maine was that a 28-year-old woman was diagnosed with Creutzfeldt-Jakob Disease (CJD) in 1997. As a child in the early 1970's, her mother believes her child had consumed venison from western Maine. She also consumed elk harvested in a western state when she was a young child.