Changing patterns of nutritional myodegeneration (white muscle disease) in cattle and sheep in the period 1975-1985 in Great Britain

Abstract

Nutritional myodegeneration of ruminants (WMD) is an acute, non-progressive myopathy affecting skeletal or cardiac muscle or both. Myodegeneration is a non-specific lesion but is predominantly associated with nutritional deficiencies of vitamin E and/or selenium in combination with environmental stress. Incidents of WMD diagnosed at Veterinary Investigation Centres have been recorded on a computer data base (Veterinary Investigation Diagnosis Analysis II) since 1975. Analyses of these data have indicated: - (a) A variable annual incidence in cattle and sheep but with a rise in incidence from 1976 to 1979 and a decline since 1980, the latter probably due to successful preventative treatment. (b) A consistent increase in incidence in spring which is more prolonged for sheep than cattle. (c) For cattle, a variation in the month of peak incidence related to the spring weather, but no broad geographical variation in the month of peak incidence was apparent in any year. The gross, histological and ultrastructural lesions in the heart and skeletal muscle are illustrated.