Polioencephalomalacia.

Polioencephalomalacia, a disease of ruminants, is most likely due to a thiamine deficiency and is most frequently associated with intensive feeding conditions or with recent changes in management. The clinical signs of incoordination and blindness followed by recumbency and opisthotonus can resolve relatively rapidly when treated early with thiamine and supportive care. The disease can frequently be prevented by thiamine supplementation and inclusion of a minimum amount of roughage in feedlot rations.