Avian reoviruses belong to the genus Orthoreovirus, and Reoviridae family. They are non-enveloped viruses that undergo replication in the cytoplasm of infected cells. Avian reoviruses are ubiquitous among poultry populations and have been responsible for viral arthritis (tenosynovitis), respiratory infections, and cloacal pasting in chicks.
The most common route of infection occurs orally, and occasionally through the respiratory tract from the nucleus of congenitally infected hatch mates. Experimental infection of adult chickens through the esophagus, nasal passages, or trachea caused the virus to spread throughout all areas of the enteric, respiratory tract, reproductive tract, and the hock and tendon joints.
Egg transmission of Avian Reovirus can occur.
Symptoms are most apparent in older birds but respiratory signs may be seen in young chicks. The incidence of reovirus infection in older birds is high, but clinical symptoms are not seen in most birds.
Avian Reovirus has been found to be a possible etiologic agent of Osteoporosis (“Brittle Bone Disease”; “Femoral Head Necrosis”) in broiler chickens, and can has been known to affect size and weight of birds.