The temporal distribution of an arthrotropic reovirus in the leg of the chicken after oral infection

One-day-old specific pathogen-free (SPF) light hybrid chicks were infected orally with an arthrotropic reovirus strain R2. At 2, 5, 8 and 10 weeks post infection (p.i.) birds were killed and tissues were taken from 7 sites in the leg for virus isolation and titration. Over the 10-week period the highest number of isolations was made from the hypo-tarsal sesamoid bone (89.7% of such specimens), followed in turn by digital flexor tendons (66.7%), articular cartilage at the hock (64.1%), gastrocnemius tendon (61.5%), head of the femur (56.4%), joint swab (30.8%) and synovial membrane at the hock (20.5%). Swabbing of the hock joint, although technically the simplest sampling method, was one of the least successful for virus recovery. Virus isolations from the articular cartilage at the hock gradually increased during the 10 weeks p.i. but decreased in the other tissues. Best correlations between the presence of gross tendon lesions and virus isolation were at 5 and 8 weeks p.i. With one exception, virus could always be recovered from specimens of hock articular cartilage which had gross lesions. For diagnostic purposes it is recommended that specimens from several birds in an infected flock, both with and without gross lesions, should be examined for virus, and the hypotarsal sesamoid bone and hock cartilage would be the tissues of choice.