What causes CWD?

CWD is caused by a prion, an abnormal form of cellular protein that is most commonly found in the central nervous system and in lymphoid tissue. The prions cause sponge-like lesions in the animal's brain. These abnormal prions tend to accumulate in certain parts of infected animals, i.e., brain, eyes, spinal cord, lymph nodes, tonsils and spleen. It is this accumulation that leads to eventual cell death, which leads to clinical signs. CWD is not caused by a virus, bacteria or nutritional imbalance.