The effect of imidocarb against Babesia Argentina and Babesia Bigemina infections of cattle.

Summary The effect of 3, 3’-bis- (2-imidazolin-2-yl)-car- banilide dihydrochloride (imidocarb or 4A65) against Babesia argentinu was evaluated in 47 splenectomised calves and 18 intact steers and its effect against Babesia bigeminu in 19 splenect- omised calves. lmidocarb readily controlled very severe infections with B. argentina at dose rates of 20 mg/kg to 1 mg/kg. B. bigeminu infections were treated successfully with dose rates of 20 mg/kg to 0.4 mg/kg. The drug was effec tive by both subcutaneous and intravenous routes. Signs of toxicity were acute following intra- venous dosages of 20 mg/kg and 10 mg/kg, although the animals survived. Toxic signs were mild or absent for subcutaneous dosages of 10 mg/kg and less. The work indicated that, for the treatment of bovine babesiosis, imidocarb was highly effective in dosages at which no toxicity was observable. The compound completely cured (sterilised) infections with B. argentina in clinically recovered steers treated subcutaneously at dose rates from