Pathophysiological effects of paraquat intoxication in domestic ruminants: low dose studies

Two studies, one in mixed breed feedlot calves and one in domestic goats, evaluated the effects of low doses of parentally administered paraquat dichloride on lung function and pulmonary structure. Calves were injected IV with 5 mg/kg paraquat and studied on days 3, 5, and 7 postinfusion. Goats were intoxicated IP with 10 mg paraquat/kg and studied on days 2, 4, 8, and 10. Each animal served as its own control. The two dosage regimes in calves and goats did not alter pulmonary function or blood gases (calf study only). Only goats intoxicated at the higher dose demonstrated histopathological paraquat-related structural changes.