Histopathological and immunohistochemical studies on cases of chronic respiratory disease in poultry

This study reports histopathological and immunohistochemical findings of chronic respiratory disease in poultry. The necropsy was performed and gross lesions were noted. Grossly, there were pneumonic changes in lung and cloudy air sacs. Microscopically, lung revealed congestion and haemorrhages, lympho-mononuclear cell infiltrates besides necrotic and denuded epithelial cells, suggestive of interstitial pneumonia. Immunohistochemistry revealed Mycoplasma gallisepticum antigen in parabronchiolar and primary bronchiolar epithelial cells and also in inflammatory cells especially macrophages. Thus, in the present study, Mycoplasma gallisepticum infection was diagnosed and confirmed by histopathology and immunohistochemistry.