Histopathologic effects of dietary cadmium on kidneys and testes of mallard ducks.

Mallard ducks fed 2, 20, or 200 ppm cadmium chloride were sacrificed at 30, 60, and 90 d. No mortality occured during the study and body weights remained unchanged. Kidney weights of the 200-ppm group were significantly greater after 60 and 90 d than those of controls; also, testis weights were significantly lower after 90 d. Kidneys of ducks fed 2 and 20 ppm cadmium were relatively unaffected; however, slight to severe kidney lesions were found in the 200-ppm group after 60 d of treatment. No significant lesions were found in mallard testes after feeding 2 ppm cadmium in the diet, and only a few birds in the 20-ppm group showed slight to moderate gonad alterations. After 90 d of treatment, however, testes of males fed 200 ppm had atrophied and the spermatogenic process had ceased. This study should provide important information for the interpretation of cadmium levels found in kidneys and testes of wild ducks.