Pathology of lung affections in poultry- A field study

The superior germplasm of intensely reared birds intended for increased production have made them vulnerable to respiratory diseases which most commonly surface too often in the field. The present study revealed that the respiratory affections have a multiple etiological agents, like bacteria (E.coli, Pasteurella), virus (Marek's, adenovirus), fungal (aspergillosis) and unsatisfactory managemental practices. The gross lesions were observed in respiratory tract of 18.50 per cent birds out of763 necropsied in Karimnagar district of Andhra Pradesh, India during 1996–99 (3 years period). The mortality was recorded as 18.42% in 0–8 weeks followed by 14.88% in 9–18 weeks and 27.18% in above 18 weeks age groups. Among 141 positive birds, 36 showed the inflammatory lesions in trachea, categorised as acute (13.48%), chronic (9.22%) catarrhal (1.42%), hypertrophy of mucosal glands (0.71%) and metaplasia of mucosa (0.71%). About eighty five birds revealed lesions in the lungs manifested as congestion and oedema (12.77%), acute interstitial pneumonia (15.60%), chronic interstitial pneumonia (13.48%), bronchopneumonia (12.78%), mycotic (2.84%), marek's disease (1.42%) and adenocarcinoma (1.42%). Twenty (20) birds showed the lesions in air sacs, which were acute (10.64%) and chronic (3.55%) in nature along with lesions in trachea and lungs.