SESSION 7: Yuko Sato

Turkey Reoviral Arthritis Yuko Sato

Dr. Yuko Sato, DVM, MS, DACPV Iowa State University

Bio

Dr. Yuko Sato received her DVM in 2012 from Purdue University. She joined Iowa State University in August 2015 after completing a poultry residency and serves as the university’s Poultry Extension Veterinarian and Diagnostic Pathologist. She is a diplomate of the American College of Poultry Veterinarians since 2015. Her extension programs focus on poultry infectious disease diagnosis, prevention, and investigation. Dr. Sato is very active in scientific organizations such as the American Association of Avian Pathologists and United States American Health Association, and is a highly sought out national speaker on poultry conferences. She also serves on numerous advisory boards locally, such as the state poultry associations, as well as nationally, including the United Egg Producers scientific advisory committee.

Turkey Arthritis Reovirus — An insight on current findings and observations

Avian Reovirus (ARV) is considered the etiologic agent of a progressive lameness condition in turkeys, Turkey Arthritis Reovirus (TARV), that emerges most often around 10-12 weeks of age in toms and less often in hens, although younger birds are occasionally affected. There is some homology in the genotype of the avian reovirus that affects chickens, however the disease does not appear to be transmitted from chickens to turkeys and vice versa. Clinical signs and gross lesions are most severe at 15-16 weeks of age, including reluctance to move, unilateral or bilateral swelling of the hock joint and gait abnormalities. In recent years, ARV has been associated in poultry causing systemic diseases including encephalitis, hepatitis (reovirus hepatitis), enteritis and other issues which indicates that the virus, once introduced hematogenously can and will go systemic.

In 2019 the National Turkey Federation Reovirus Subcommittee released three documents to the industry, including the case definitions and nomenclature, diagnostic & testing reference listing contacts of 6 TARV researchers and the tests available and results of an industry survey titled, Economic Impact of Turkey Arthritis Reovirus. According to this report, there is an average of 5.6 cent increased cost per pound for flocks affected by TARV compared to unaffected flocks. The 2019 Survey reports approximately 2% incidence of all turkeys produced annually and primarily affects toms (approximately 5% incidence of toms produced annually). The severity of impact on the industry could be as high as $33.7 million. However, annual surveys polling turkey veterinarians on important health issues have progressively ranked TARV lower down the last few years, presuming its diminishing incidence or impact within the turkey industry.

Ongoing challenges with TARV include questions surrounding 1) pathogenesis (where does it come from?), 2) accurate diagnosis as it pertains to subtyping/serotyping to look at genetic diversity of the virus, and 3) control methods (combined efforts of breeder vaccination, commercial farm biosecurity and flock management protocols all warranted).