Occurrence and potential causative factors of immune-mediated hemolytic ‎anemia in cattle and river buffaloes

The main objectives of this study were to determine the occurrence and potential causative factors of Immune-mediated hemolytic anemia (IMHA) in native cattle and water buffaloes from southwest of Iran. Fifty-three anemic animals (37 cattle and 16 buffaloes) were studied. A full clinical history and physical examinations were undertaken for all animals. Four clinically healthy cattle and four healthy buffaloes were also used as control animals. Blood samples were subjected to a complete blood count, Coombs' test, erythrocyte osmotic fragility test and serum biochemical analysis. IMHA was diagnosed in 12 (32.43%) cattle and 6 (37.50%) buffaloes based on the Coombs' test. Underlying or concurrent diseases, including theileriosis, anaplasmosis, vaccination, and pneumonia were detected in 11 cattle and four buffaloes. Primary or idiopathic IMHA was identified in one cattle and two buffaloes that their Coombs' test was positive. Hematologic and biochemical findings in the cattle with IMHA included a nonregenerative anemia, leukopenia, thrombocytopenia, increased osmotic fragility, hyperbilirubinemia and elevated serum alkaline phosphatase, aspartate aminotransferase and lactate dehydrogenase activities. It can be concluded that IMHA occurs in a significant proportion of anemic cattle and river buffaloes in southwest of Iran. The occurrence of IMHA in both cattle and buffaloes is mostly secondary to infectious diseases especially theileriosis and anaplasmosis. Clarification of the mechanisms of primary or idiopathic and secondary IMHA in cattle and buffaloes require further studies.