Ten live 20-day-old, meat type chickens were submitted to the Texas A&M Veterinary Medical Diagnostic Laboratory’s (TVMDL) Center laboratory with a clinical history of leg problems and swollen tendons.
At necropsy examination the birds exhibited outwardly deviated legs, moderately swollen hocks with an accumulation of a tannish, turbid exudate, and swollen gastrocnemius tendons.
Serology for reovirus was positive in all the birds by the ELISA test. The histopathological examination revealed tenosynovitis and epicarditis with lymphoid aggregate formation, lesions consistently found in systemic reovirus infections. Reovirus was isolated from the affected tendons.
Some strains of reovirus can cause viral arthritis. These strains are transmitted both vertically and horizontally in poultry. Viral arthritis may cause rupture of the gastrocnemius tendons in heavy birds. Viral arthritis in broilers can be prevented by maternal immunity.
