Outbreaks of Anaplasmosis in Dairy Cattle in Punjab, India

Two severe outbreaks of bovine anapalsmosis caused by Anaplasma marginale were recorded in two districts (Ferozepur and Patiala) of Punjab state in the year 2016. Mortality of animals was recorded in two dairy cattle herd comprising of a total of 260 animals in Ferozepur (n=218) and Patiala (n=42) districts. There was history of purchase of animals at one farm. Out of 260 cattle at risk, 40 were critically ill and 9 died of disease with morbidity, mortality and case fatality rate of 15.38%, 3.46% and 22.50% respectively. Fifteen blood samples were collected from diseased (n=11) and healthy animals (n=4) for haematological analysis, parasitological and polymerase chain reaction (PCR) based diagnosis. Clinical signs in infected animals included high temperature, icterus, anemia, anorexia and decreased milk production. Necropsy findings revealed splenomegaly and severe jaundice. Mild tick infestation was observed at both the farms. Ticks collected from both the outbreaks were identified as Rhipicephaus (Boophilus) microplus. Thin blood smears from infected animals were found positive for Anaplama marginale organisms & disease was further confirmed by molecular approach (PCR). Affected animals were successfully treated with tetracycline, haematinics and antipyretics. PCR was found to be more sensitive in detecting the disease especially in latent infections. Animal owners were advised to follow quarantine measures before mixing new animals in a herd and strategic acaricidal treatment for effective tick control.