Neurological changes in cats following long-term diet of mercury contaminated tuna
Young kittens of both sexes were fed daily with mercury contaminated tuna (containing about 0.5 ppm mercury). Neurological disturbances similar to those in Minamata disease or in experimental mercury intoxication (ataxia, weakness and incoordination of movements) were observed after 7–11 months of the experimental course. Microscopic examination revealed degenerations of the granular layer and some Purkinje neurons in the cerebellum. Neuronal necrosis was also observed in the cerebral cortex. The present investigation suggests that fish containing 0.5 ppm mercury (U.S. Food and Drug Administration approved level) may still be potentially hazardous to health when consumed in excessive amounts for prolonged periods of time.