Quinuronium sulphate for the treatment of Babesia divergens infections of splenectomised calves.

Quinuronium sulphate was inoculated into splenectomised calves at various times in relation to artificial infection of the calves with Babesia divergens. When the drug was given one day before the parasites it had no effect on the course of the infection. However, when it was given at the time of onset of fever or haemoglobinuria, development of the infection was arrested. Two weeks after therapy, recrudescences of parasites invariably occurred. In the case of animals treated at onset of fever these recrudescences were accompanied by increasing anaemia. Treated animals resisted subsequent challenge but remained as carriers of the parasite.