Mannosidosis in Aberdeen Angus cattle in Britain

Mannosidosis, an inherited and lethal lysosomal storage disease of Aberdeen Angus cattle, was diagnosed on a farm in north-east Scotland. Two affected calves were examined in detail. Both were poorly grown and ataxic, though the intention tremor and aggression considered characteristic of the disease were not recorded. Histological examination revealed typical vacuolation of nerve cells, fixed macrophages and epithelial cells of the viscera. Deficiency of the enzyme alpha mannosidase was demonstrated. The epidemiology of the disorder in Scotland is considered and control methods indicated.