Bovine Spongiform Encephalopathy (BSE)

BSE (Bovine Spongiform Encephalopathy) is a disease of cattle called spongiform encephalopathy. It was first confirmed at U.K. in 1986.
It was named bovine spongiform encephalopathy because the brain of a cow with BSE becomes spontaneous and becomes sponge-like.
The disease is thought to be caused by a type of protein called "prion", which is smaller than the virus. Animals originally have normal prion proteins, but it is "abnormal prion proteins" that cause the disease. When an abnormal prion protein enters the body of a cow, normal prion proteins are transformed into abnormal prion proteins one after another. When the changed abnormal prion protein accumulates in the brain and nerves, after an incubation period of 2 to 8 years (usually 2 to 5 years), vesicles develop in the brain and nerves, showing behavioral abnormalities and motor dysmobility. Will be It is sometimes referred to as mad cow disease due to its symptoms, but this is not an accurate representation of the condition of BSE and is not appropriate. Cattles die in two to six months after onset.

We do not yet know more about the occurrence of BSE.
Meat and bone meal was made by processing and processing internal organs, skins, bones, etc. that remain after removing meat from cows, etc., and was used as fertilizer and livestock feed. It is thought that the mixture of cows with BSE in this meat and bone meal material caused the spread of BSE infection. In this way, BSE is transmitted by eating an abnormal prion protein, a pathogen, but it is not transmitted through contact between cows or through air.

Abnormal prion proteins have been confirmed to be concentrated in some parts of the body, such as tonsils of cows and distant ditums with BSE. Therefore, these parts are designated as specific parts by law and are subject to removal.
Specific part

• Tonsils of all ages, distant dinal areas
• Head over 30 months of age (excluding tongue, cheeks, skin, and tonsils), spinal cord

Yokohama City Meat Sanitation Laboratory website
Ministry of Health, Labour and Welfare website (outside site)
Ministry of Agriculture, Forestry and Fisheries website (outside site)