Generalized tuberculosis in a 45 day-old calf.

The objectives of the present study were to describe pathomorphological and immunohistochemical features of generalized natural tuberculosis in a 45 day-old female calf. The characteristic lesion of tuberculosis was productive type which was located in the lung, liver, and especially in the lymph nodes (mediastinal, bronchial, mesenterial, portal, prescapular, renal and caudal sternal lymph nodes). Mycobacterium bovis antigens were seen generally in the cytoplasma and around the macrophages, rarely in necrotic areas and Langhans giant cells by avidin-biotin complex peroxidase method.