Lesions induced in the respiratory tract of chickens by serologically different adenoviruses

Ten strains of adenovirus representing 10 serotypes were administered intratracheally to two groups of 3-week-old specific-pathogen-free chickens. Birds in group 1 were given only adenovirus. Birds in group 2 were inoculated with a virulent infectious bursal disease virus (IBDV) by eye-drop at one day of age as well as with the adenovirus at 3 weeks. The chicks were examined daily. Respiratory rales were observed in some birds with the dual infection. Gross pathologic alterations were minimal and limited to multiple scattered, pale foci in the lungs of an occasional bird in various groups. Histopathologic changes in the lungs were those of multifocal interstitial and, occasionally, diffuse pneumonia. The pneumonic lesions were more severe in the chickens given IBDV. Tracheitis was seen with two of the serotypes.