Bovine spongiform encephalopathy (BSE)

What is BSE?

BSE belongs to the Transmissible spongiform encephalopathies (TSE) group of diseases. It is a fatal brain disease of cattle. The infectious agent is thought to be a protein called a prion. It is believed that in the past animals became infected by eating animal feed containing the infectious agent.

BSE was first diagnosed in the UK in 1986 and has since appeared in many other countries including Europe, North America and Japan. Good progress is being made towards its eradication in the UK.

Clinical signs

Signs of the disease are not usually seen until the cow is at least 4 or 5 years old. They tend to develop slowly and may include a strange high stepping gait, trembling, nervousness or aggression and loss of weight.

Human form

The disease in people, variant Creutzfeldt-Jacob disease (vCJD), was first identified in 1996 and has been linked with eating meat products from BSE infected animals.

Recent research

It was thought that the BSE agent was a stable, single strain or type but in recent years a small number of cases with different molecular and pathological characteristics have been reported in Europe (including GB), Japan and the USA. The zoonotic potential of these atypical BSE cases is at present unknown.