The effect on newborn chicks of oral inoculation of reovirus isolated from chickens with tenosynovitis

Reovirus strain 176, isolated from chickens with tenosynovitis, was highly pathogenic following oral inoculation of 1-day-old specific-pathogen-free chicks. Disseminated lesions including hepatic necrosis, splenic lymphostromal cell hyperplasia, and bursal atrophy occurred on day 3 postinoculation (PI), followed by myocarditis on day 6 PI and by pericarditis and tenosynovitis on day 9 PI. Reovirus was isolated from the liver as early as day 1 PI, whereas significant neutralizing antibody was detected on day 13 PI. Mortality occurred from day 4 to day 7 PI, and the death of birds was associated with the severity of hepatic necrosis. The occurrence of tenosynovitis in virus-inoculated birds was subclinical.