Nutritional encephalomalacia in turkeys: diagnosis and growth performance.

An outbreak of neurological disease in 2 1/2-to-3 1/2-week-old male turkey poults was diagnosed morphologically as nutritional encephalomalacia. About 20 to 30% of the flock of 6360 showed clinical signs, which included going down with legs extended or hock-sitting and inability to get up, incoordination, weakness, staggering, trembling, torticollis, and opisthotonus. The most important gross postmortem changes were found in the brain, which consisted of an enlarged and swollen cerebellum with focal and/or diffuse hemorrhages. Major histopathological alterations included congestion, hemorrhages, necrosis, and malacia associated with hyaline capillary thrombi affecting the cerebellar cortex and adjacent white matter. Except for a slightly higher mortality, flock performance compared favorably with performance of other flocks grown in the same farm as well as with the national average for market tom turkeys.