Bovine Spongiform Encephalopathy (BSE) was first reported from the United Kingdom (UK) in 1986. Approximately 190,000 BSE cases were reported in the world, about 185,000 cases were detected in UK so far. BSE were transferred among cattle by Meat and Bone Meal with an inadequate heat treatment produced from Specified Risk Materials (SRM) of BSE cattle. Infectious agent is a proteinaceous infectious particles (prion), these are causative agents of BSE and also of variant Creutzfeldt-Jakob Disease (vCJD) in human. 178 cases of vCJD cases were reported in the world since 1995. One case was also reported in Japan.

130 atypical BSE cases were reported in the world. Atypical BSE has a different western blot pattern from typical BSE. There are two patterns, High and Low types. Atypical BSE case was borne sporadically, and onset of BSE symptoms were detected older than typical BSE case. Two L type cases were detected in Japan in 16,100,000 cattle tested so far.

To prevent dissemination of BSE in the world, feed ban which is not fed SRM to cattle was introduced. 65 BSE cases were borne after real feed ban in the world.

No typical BSE case was reported in 2017, therefore, typical BSE case will be eradicated near future in the world.