Butler, C. II, and Kleinerman, J. (1971). Brit. J. industr. Med., 28, 67-71. Paraquat in the rabbit. Forty rabbits received paraquat intraperitoneally in total dosages of from 2 to 100 mg/kg and in one to five separate administrations. Nine animals which received 25 mg/kg or more died within four days of administration, and the remainder were killed at intervals of up to one month. The delayed pulmonary changes produced in man and other species by paraquat were not found in any animal, despite the fact that most animals were made ill by the chemical. Atrophy of the thymus and minimal renal tubular and focal peritoneal changes were present in animals found dead or killed soon after administration, but it was difficult to explain the cause of death.