Prion diseases: A challenge to animal health.

Prion diseases are known as transmissible spongiform encephalopathies (TSE), a group of rare, rapidly progressive, and fatal neurologic diseases. The agents responsible for human and animal prion diseases are abnormal proteins (prion or proteinaceous infectious particle) that can trigger chain reactions causing normal proteins in the brain to change to the abnormal protein. These abnormal proteins are resistant to enzymatic breakdown, and they accumulate in the brain, leading to damage. All have long incubation periods followed by chronic neurological disease and fatal outcomes, have similar pathology limited to the CNS include convulsions, dementia, ataxia (balance and coordination dysfunction), and behavioral changes, and are experimentally transmissible to some other species.