ISSN 2141-2375 ©2011 Academic Journals

A study was undertaken to study respiratory tract infections in sheep. One hundred and eighty sheeps in a flock were included in present study. The prominent clinical signs of the infection included pyrexia, coughing, respiratory distress, nasal discharge, ocular opacity. In some cases, hot and swollen joints, lameness and depression also appeared. Routine post-mortem examination was conducted on fifteen dead sheep. This examination revealed the presence of characteristic lesions (including reddening, consolidation, and purulent focal and localized necrosis in different areas of the lung), fibrinopurulent membrane on the pleural surface and serofibrinous fluid in the thoracic cavity. Specimens were aseptically collected for histopathological and bacteriological examinations. The pneumonic lungs, liver and thoracic lymph nodes and nasal swabs were inoculated into liquid and solid media. Colonies on solid media were visible microscopically (X50) after 24 h at 37°C. A detailed microscopic examination revealed that the lesions were the form accumulation of collagen connective tissue, lung tissue necrosis, hyperemia and vasculitis in vessel walls, with infiltration by macrophages, neutrophils and thrombus formation. A high microscopic magnification observation showed bacterial colonies in most of the alveolar spaces