Levamisole residues in milk from a herd of cows suffering from lungworms

A single intramuscular dose of 7 mg levamisole hydrochloride per kg body weight was administered to a herd of 42 milking cows suffering from lungworms. Levamisole was rapidly excreted in the milk, the peak concentration being found 1 h after administration. The half-life of levamisole in milk was about 5 h. Levamisole levels were below the limit of determination (0.04 microgram/ml) in all milk samples 29 h after treatment.