The effect of Imidocarb treatment on Babesia in the bovine and the tick (Boophilus microplus).

Treatment of calves with 5 mg/kg Imidocarb (3,3-1-bis-(2 - imidazolin - 2 - yl)carbanilide dipropionate) given intramuscularly 14 days before and 14 days after exposure to Babesia infected Boophilus microplus larvae rendered the next generation of larvae incapable of transmitting Babesia infection. When administered to calves 14 or 28 days before tick exposure, the drug prevented the development of clinical babesiosis; the larval progeny of ticks reared on the calf which was treated 28 days before infestation were infective. Treatment of a calf 42 days before exposure to infective larvae did not prevent the development of a Babesia parasitaemia but appeared to reduce the severity of infection.