Chemotherapeutic value of parvaquone and buparvaquone against Theileria annulata infection of cattle.

Parvaquone (BW993C), 2-cyclohexyl-3-hydroxy-1,4-naphthoquinone, and buparvaquone (BW720C) 2-(trans-4-t-butylcyclohexyl-methyl)-3-hydroxy-1,4-naphthoquinone, were evaluated to determine their therapeutic efficacy in the treatment of theileriosis caused by Theileria annulata infection in cattle in Iran. One hundred and fifty-nine pure and crossbred Bos taurus cattle, experimentally or naturally infected with T annulata, were treated. Parvaquone was injected into 86 animals with up to three doses of 20 mg kg-1 or 10 mg kg-1 at intervals of 48 hours between doses. Buparvaquone was injected into 73 animals. Up to three doses of 2.5 mg kg-1 were injected with an interval of 48 hours between doses. The recovery rate of animals treated with parvaquone was 60.7 per cent and with buparvaquone it was 88.7 per cent. No significant side effects of relapse of disease were observed following the use of either compound. It is concluded that buparvaquone at a dose of 2.5 mg kg-1 has a satisfactory therapeutic index and is a more effective treatment of T annulata infection than parvaquone. The prophylactic use of schizont tissue culture vaccine and chemotherapy with buparvaquone could be the most promising means of controlling theileriosis in Iran.