Avian reoviruses (ARVs) and fowl adenoviruses (FAdVs) are ubiquitous, variably pathogenic viruses that are responsible for several economically costly diseases in commercial broilers due to high morbidity or mortality.

Pathogenic reoviruses are etiologic agents of viral arthritis and tenosynovitis in chickens and turkeys and have been associated with several additional clinical syndromes, including stunting/malabsorption syndrome and enteric disease, hepatitis, immunosuppression, myocarditis, and respiratory disease​. As of yet, no genetic or antigenic factor has been found to be predictive of an avian reovirus’s clinicopathologic manifestation of arthritic, enteric, or other disease. ARVs within genetic cluster (GC) 2 have been isolated from both arthritis and enteritis clinical cases. Here, the pathogenesis of a GC 2 isolate was examined via histopathology, in situ hybridization, and PCR, and the isolate was found to infect both epithelial cells within the intestine and synoviocytes within the tendon sheath.

Fowl adenoviurses are the etiologic agents of inclusion body hepatitis (IBH) and hepatitis-hydropericardium syndrome (HHS) in chickens, which both cause acute hepatic necrosis with flock high mortality rates. Rapid, cost-effective diagnosis of IBH can streamline further confirmatory laboratory testing and facilitate timely communication in the interim to affected parties, especially in locations with delayed access to a diagnostic laboratory. Here, Romanowsky-stained impression smear cytopathology of the liver at the time of necropsy is demonstrated to successfully stain IBH intranuclear inclusion bodies, and IBH diagnosis via cytopathology maintains high agreement to the histopathologic diagnosis