Infectious coryza in birds complicated by other bacterial infections

Infectious Coryza (IC), caused by Avibacterium paragallinarum, is an infectious and highly contagious bacterial respiratory disease of poultry. The present communique deals with the pathological investigation of complicated cases of Infectious Coryza. The dead birds with nasal/lacrimal discharge and swollen sinuses were screened for the presence of Avibacterium paragallinarum and other concurrent bacterial infection by PCR and microbial culture, respectively. The birds (n=08) found positive for Avibacterium paragallinarum were also found to be infected with other bacteria like E. coli, Klebsiella, Salmonella and Pseudomonas. Pathologically, fibrinous deposits were seen in airsac, liver and heart of all the birds but more severe changes were seen in birds with concurrent E. coli infection. The histopathological lesions like tracheitis and deciliaton were consistently observed in the trachea, and lungs from all birds with complicated coryza and also showed interstitial pneumonic changes. All these cases were diagnosed as complicated cases of infectious coryza.