Avian reovirus infection in turkeys with neurological disease in Alberta.

Avian reoviruses (ARVs) are ubiquitous and play a role in diseases affecting various organs in chickens and turkeys. In recent years, tenosynovitis and lameness emerged as the most frequently reported clinical conditions. In this report, we describe a case of neurological disease associated with ARV infection in 4-week-old turkeys in Alberta. A flock of 7650 commercial turkey toms exhibited neurological signs such as torticollis and ataxia that affected ~3 to 4% of birds in the flock. Histologic examination of brain samples collected at 6 wk revealed nonsuppurative encephalitis. A pooled brain sample was positive for ARV by PCR. By 9 wk of age, birds in the flock started developing lameness with no apparent neurological involvement, and tendon samples were positive by PCR. Partial sigma C gene amino acid sequences were obtained for the brain and tendon samples and were 91.4% identical. The brain and tendon samples showed 95.5% and 97.7% amino acid identities to ARVs from Ontario (ARV/Turkey/ON/17-049928) and Pennsylvania (ARV/Turkey/PA/01769-14), respectively. Similar cases are currently being investigated in western Canada. Key clinical message: Avian reoviruses should be considered one of the differential diagnoses in cases of neurological signs in commercial birds.