Drug resistance in blood parasitic infections in cattle: a review.

Generally the most common blood parasites identified in cattle are protozoa in the genera Trypanosoma, Theileria, Babesia, and rickettsia in the genus Anaplasma. These parasites can cause clinical symptoms and productivity loss which will therefore consequently in economic loss. At present, blood parasite infection in cattle often has poor treatment outcomes and there is an increase of reports which indicating that drug resistance may occur in treating infections. Trypanosoma vivax, T. congolense, and T. brucei have been reported for resistance to isometamidium chloride and diminazene aceturate drug. Babesia bovis is resistant to diminazene aceturate drug, and Anaplasma marginale and A. centrale are resistant to oxytetracycline drug. The most common methods for diagnosing drug resistance are block treatment, in vivo standardized drug sensitivity tests, and molecular tools. Drug-resistant causes a decrease in treatment performance, therefore, new methods have been developed for choosing appropriate treatment of blood parasitic infection including using a primary drug combined with other substance, using herbal extracts, or developing a new effective drug.