The study was carried out to assess the status of theileriosis in cattle and buffaloes using biochemical levels of serum calcium, phosphorous and adenosine deaminase. Cattle and buffaloes naturally infected with Theileria annulata and Theileria orientalis were examined through biochemical analysis and the estimates were correlated to determine the severity of infection, immunological responses and the extent of tissue damage. A total of 50 cattle and 50 buffaloes were sampled for the study which included both infected and noninfected group. For calcium and phosphorous estimation, commercial kits were used whereas for adenosine deaminase, chemicals were prepared manually in Veterinary Parasitology lab, Nagpur, and the activity was estimated using nano-drop spectrophotometer. | Biochemical basis for diagnosis of theileriosis in cattle and buffaloes