Novel tools for the diagnosis and differentiation of acute and chronic bovine besnoitiosis

► Diagnostic Besnoitia besnoiti antigens were enriched by affinity purification. ► Several diagnostic antigens are located on the surface of tachyzoites. ► The phase of infection determines the recognised diagnostic antigen pattern. ► Affinity purified antigens were used to establish an APure-BbELISA. ► Low avidity in ELISA confirmed primary infection in cattle developing besnoitiosis.