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CEREBELLAR defects are common in livestock. They can be classified into cerebellar hypoplasia, which results from arrested development of the cerebellum, and cerebellar abiotrophy, which results from accelerated or premature degeneration of formed cerebellar tissue ( Jubb and Huxtable 1985 ). Cerebellar hypoplasia is further divided by aetiology: intrauterine or neonatal infection, and inherited disorders ( Washburn and Streeter 2004 ). Intrauterine infections causing cerebellar hypoplasia include bovine viral diarrhoea virus ( bvdv ), Akabane virus, bluetongue and Aino virus ( de Lahunta 1980 , Tsuda and others 2004 ). Hereditary cerebellar hypoplasia is reported to be the result of an autosomal recessive trait in a number of breeds of cattle ( Finnie and Leaver 1965 , Edmond and others 1973 , O'Sullivan and McPhee 1975 , Swan and Taylor 1982 ). The clinical signs of cerebellar hypoplasia are generally symmetrical and comprise different grades of ataxia, a dysmetric-hypermetric gait and a slight head tremor that is exacerbated with movement (intention tremor). Abnormal nystagmus and decreased menace reaction may occur in severely affected calves. Cerebellar hypoplasia is found relatively rarely in adult cattle, compared with calves. The signs are present at birth and do not worsen with age ( de Lahunta 1980 ). This short communication describes cerebellar hypoplasia in an adult cow suspected of having bovine spongiform encephalopathy ( bse ).
A four-year-old Italian Friesian cow was referred to the National Reference Centre for Transmissible Spongiform Encephalopathy, Turin, because of a three-month history of abnormal gait and changes in behaviour, which included dancing-like movement of all four legs, together with opisthotonos and side-to-side swaying of the head after stimulation. These clinical signs had recently worsened. On-site physical examination was normal, except for a traumatic lesion at the base of the left horn. Neurological examination revealed that the cow was hyperexcitable, nervous, and salivated when approached. Both tactile and acoustic stimuli elicited positive responses; the light test was negative ( Braun and others 1997 ). Touching the hocks with a broom (the broom test) ( Braun and others 1997 ) did not elicit kicking, but rather a dancing-like behaviour as described by the...