Subacute toxicity of dietary heptachlor to mink (Mustela vison).

Mink were fed diets that contained 0, 12.5, 25, 50, or 100 mg/kg active ingredient heptachlor (as technical grade formulation) for 28 days followed by a 7-day observation period to determine the toxicity of this insecticide to mink. Diets that contained 25 mg/kg, or more, heptachlor resulted in a significant decrease in feed consumption, while 50 mg/kg, or more, heptachlor caused a significant reduction in body weights. Mortality (37.5%) occurred only in the group fed 100 mg/kg heptachlor. The dead mink showed neurological signs of toxicity prior to death. Animals fed 100 mg/kg heptachlor also had reduced relative weights of the spleen and kidney and increased relative weight of the adrenal glands when necropsied at the time of death or at the termination of the study.