Clinical signs and diagnosis of BSE

Abstract

Bovine spongiform encephalopathy (BSE) in cattle is characterised by typical signs and an insidious course. There is gradual weight loss and decreased milk production, and the disease is distinguished by disturbances in behaviour, sensitivity and locomotion. The most common behavioural changes are apprehension and abnormal temperament. The most common changes in sensitivity are hypersensitivity to tactile, auditory and optical stimuli, kicking during milking and excessive licking of the muzzle. The most important disturbances in locomotion include ataxia, falling down and inability to get up. Diagnostic procedures include a thorough clinical and neurological examination followed by a more detailed examination to assess behaviour, locomotion and sensitivity to touch, sound and light stimuli. Other causes of central nervous system disease may be ruled out by a complete blood count, biochemical profile, urinalysis and examination of cerebrospinal fluid. Disturbances in behaviour, locomotion and sensitivity that occur singly, rather than in combination with each other, should be interpreted with caution. However, in cattle with disturbances in two or more of these categories, a tentative diagnosis of BSE can be made, and the veterinary authorities must be notified.