First diagnosed in Great Britain in 1986, it has since been confirmed in domestic cattle in Belgium, France, Ireland, Liechtenstein, Luxembourg, the Netherlands, Portugal, Switzerland, Spain, Germany, Italy and Denmark. Australia does not have BSE and is one of only 11 countries in the world to date assessed by the European Union as meeting all criteria for its lowest geographical BSE risk level. Clinical signs Cattle affected by BSE may display nervousness or aggression, abnormal posture, poor coordination, difficulty in rising, decreased milk production, or loss of body weight despite continued appetite.
Affected cattle die.
The causative agent in BSE is generally accepted to be an abnormal prion protein. There is no treatment or vaccine to prevent these diseases. The incubation period is from two to as long as 12 years and following onset of clinical signs the animal's condition deteriorates until it either dies or is destroyed usually within two weeks to six months. BSE is confirmed by post-mortem microscopic examination of brain tissue or by detection of the abnormal form of the prion protein. BSE is so named because of the spongy appearance of the brain tissue of infected cattle when sections are examined under a microscope.