Bovine Spongiform Encephalopathy (BSE), also known as Creutzfeldt-Jackob disease (CJD), is a family of disease that degenerate the central nervous system of a number of species including humans, cows, and cats. The disease is transmissible. It may remain dormant for four to five years before becoming fatal. Many researchers believe that the disase is caused largely by a self-replicating protein, called prion. The protein may be transmitted from eating BSE-contaminated meat. It may also be transmitted through air.

Prion: Prion is observed to be a self-replicating protein responsible for Bovine Spongiform Encephalopathy (BSE). As it may remain inactive for years, it is hard to detect and to assess.