Polioencephalomalacia in cattle in New Zealand fed chou moellier (Brassica oleracea).

Polioencephalomalacia was diagnosed clinically in 26 heifers from a herd of 99 grazing chou moellier (Brassica oleracea). Clinical signs included ataxia, recumbency, blindness and aimless walking. Characteristic polioencephalomalacic autofluorescence was seen under long ultraviolet radiation of four fresh brains examined in the veterinary clinic and two formalin-fixed brains sectioned and examined in the laboratory. Haemorrhage and malacia were noted grossly and microscopically in the cranial colliculus, thalamus and hippocampus of two brains sectioned in the laboratory, while multifocal vasculitis was seen in one brain. High sulphur concentrations of 8500 mg/kg DM in the chou moellier and a recent change in grazing management were the most likely causes of the outbreak.