Efficacy of imidocarb diproprionate and primaquine phosphate in the prevention of tick-borne disease in imported Hereford heifers in South Korea.

This paper describes the build-up of tick-borne blood parasites in a group of Hereford heifers imported from New Zealand to the island of Jeju Do, South Korea. All became infected with Theileria sergenti and half with Babesia bigemina. An attempt was made to contain the 2 parasites by treatment with either primaquine phosphate or imidocarb diproprionate. Both drugs had some prophylactic activity against T. sergenti for at least 26 days and imidocarb dipropionate eliminated B. bigemina. Since T. sergenti infections built up subsequently in the animals it is suggested that repeated prophylaxis combined with regular acaricide treatment of imported cattle is necessary to keep piroplasmosis under control.