Mycobacterium orygis associated generalised tuberculosis in Indian Cattle

The present report describes two cases of generalised tuberculosis in cattle caused by Mycobacterium orygis. The affected cattle, both adult female cows from an organized dairy farm in Bareilly, Uttar Pradesh exhibited severe clinical signs including weakness, lethargy and respiratory distress and succumbed to the disease despite treatment efforts. Necropsy examination revealed marked emaciation, a rough body coat and pale mucous membranes. Gross lesions consisted of variably sized caseo-calcified nodules in multiple organs, including the lungs, lymph nodes (prescapular, mediastinal, mesenteric), kidneys, udder, uterus, meninges and brain. Histopathological examination revealed diffuse caseo-calcified granulomas in above mentioned organs. Duplicate sections of various organs were positive for acid-fast bacilli on Zeihl-Neelsen staining. Generalized tuberculosis caused by M. orygis was diagnosed based on pathomorphology, Ziehl-Neelsen staining, culture isolation and multiplex PCR. This report highlights the broader implications of mycobacterial infections in livestock and the potential risks to public health.