Inclusion body tracheitis associated with avian adenovirus in turkeys

Nine turkey flocks with basophilic intranuclear inclusion bodies, suggestive of adenovirus, within the epithelial cells of the tracheal mucosa were studied. Respiratory signs and increased mortality occurred in turkeys between 6 and 10 wk of age from nine commercial turkey meat flocks in central California. Necropsy findings included tracheitis and occasional mild sinusitis. Histopathology of the tracheas revealed epithelial deciliation, squamous metaplasia, large basophilic intranuclear inclusion bodies within epithelial cells, and lymphoplasmatic inflammation in the mucosa. Electron microscopy of the mucosa revealed hexagonal viral particles, approximately 73 nm in diameter, consistent with adenovirus within the nuclei of epithelial cells. All tracheal sections were negative for adenovirus group II by specific immunoperoxidase staining. Adenovirus group I was isolated from the trachea. In addition, Bordetella avium, Ornithobacterium rhinotracheale, and Klebsiella pneumoniae were isolated from the tracheas of three, three, and two flocks, respectively. Statistically greater total mortality and a smaller percentage of marketed turkeys were observed in the submitted flocks than in randomly selected flocks. No significant difference was observed between the two turkey groups in market weight, feed conversion, or percentage of grade "A" turkeys.