Prevalence and pathology of respiratory lesions in commercial meat type chickens

Respiratory infections are the most common threat for the commercial poultry production worldwide. The present study was conducted to determine the prevalence and pathology of respiratory affections in broilers. During the study period of eight months stretching from July 2017- February 2018, a total of 339 post-mortem examinations were done in broilers covering twenty different poultry flocks. Of these, gross respiratory lesions were observed in 104 cases. The prevalence of respiratory lesions in broilers of Jabalpur region was determined as 30.67%. Maximum number of birds with respiratory lesions was observed in month of February. The nasal passage was affected in 100% of the broilers with respiratory lesions followed by trachea (79.84%), air sacs (78.84%), lungs (68.26%) and sinuses (57.00%). Catarrhal tracheitis (59.03%) and moderate airsacculitis (32.92%) were observed in maximum number of birds with respiratory lesions. Trachea and lung were collected from sixty broilers showing gross respiratory lesions and were processed for histo- pathology. Microscopically, congestion, haemorrhage, infiltration of leukocytes, mucosal thickening and surface epithelial destruction were observed in trachea. In lungs, congestion, haemorrhage, infiltration of leukocytes, oedema, respiratory atrial muscle thickening and necrosis and denudation were noticed.