The deficiency of vitamin E in poultry is manifested in three different forms: encephalomalacia, muscular dystrophy and exudative diathesis. Each of them is usually encountered independently, although sometimes they occur at a time. Encephalomalacia (crazy chick disease).
The signs are associated with central nervous system lesions. They include ataxia, disequilibrium, falling on the back, frequent movements with the wings, strongly stretched legs (clonic spasms) and twisting of the head. Rarely, torticollis or opisthotonus could be observed.