Field evaluation of parvaquone against naturally occurring East Coast fever.

Parvaquone (Clexon Cooper) was clinically tested for efficacy as a treatment for East Coast Fever (Theileria parva parva infection) in naturally infected cattle. The drug showed a suppressive effect on Theileria schizonts and piroplasms. A recovery rate of 79% was recorded. Best results were obtained when Clexon treatment was initiated in the early stage of the disease, before many red blood cells were invaded and before respiratory distress was evident. A carrier state in animals recovered from East Coast Fever is suspected.