Gingival hyperplasia induced by diphenylhydantoin in a gorilla.

An adult male lowland gorilla had been treated with diphenylhydantoin for 6 months following several acute convulsive episodes. The gorilla remained clinically normal during that period. Then, for no apparent reason, it refused its usual diet. Physical examination revealed acute inflammatory gingival hyperplasia. Full mouth gingivectomy and antibiotic and analgesic therapy resolved the oral inflammation and the anorexia.