[Scrapie from the clinical aspect]

Abstract

The first cases of scrapie in the Federal Republic of Germany since 1945 occurred in 1990 and 1991. The disease was found in three flocks of Suffolk sheep and it was probably brought to Germany by breeding sheep from France. Scrapie is a transmissible degenerative disease of the central nervous system with a slowly progressing but always fatal course. The scrapie agent is highly resistant against environmental influences as well as against disinfectants. Incubation period and clinical signs of scrapie vary from flock to flock, depending on genetical factors of infected sheep and depending on the involved scrapie strain. In infected flocks normally not more than 1% of the sheep show clinical symptoms. Affected sheep are usually more than two years old (maximum incidence at three years of age). First signs of the disease may be changes in behaviour or pruritus or locomotor symptoms. When the disease progresses, all sheep loose flesh and within some weeks up to some months they get weaker and weaker until they finally die in recumbency. Scrapie cannot be detected in living animals and the disease may be overlooked during autopsy, because in the final stage of the disease many sheep die from non-specific secondary infections. In suspected cases of scrapie, the practicing veterinarian must give a precise history to the pathologist and he must ask for histopathological examination of the brain.