Specific-pathogen-free Turkey model for reoviral arthritis

Area of Science:

• Avian Pathology
• Virology
• Immunology

Background:

• Turkey arthritis reovirus (TARV) causes significant economic losses in the U.S. turkey industry.
• Studying TARV pathogenesis and vaccine efficacy in commercial turkeys is challenging due to co-infections.
• Specific-pathogen-free (SPF) turkeys offer a controlled environment for disease modeling.

Purpose of the Study:

• To evaluate SPF turkeys as a model for TARV-induced arthritis.
• To characterize the clinical and pathological signs of TARV infection in SPF turkeys.
• To assess TARV transmission and the impact of stress on disease progression.

Main Methods:

• SPF turkey poults were orally inoculated with TARV (O'Neil strain) or a gut isolate (MN1 strain).
• Birds were monitored for disease onset, progression, and pathological changes.
• Sentinel birds were used to assess TARV transmission; dexamethasone was used to simulate stress.

Main Results:

• Only TARV-infected birds developed clinical signs, including hock swelling, tenosynovitis, cartilage erosion, and lameness.
• TARV infection led to a significant decrease in body weight.
• TARV was effectively transmitted to sentinel birds, causing severe tenosynovitis and cartilage erosion.
• Dexamethasone treatment did not alter viral load or disease severity.

Conclusions:

• The SPF turkey model accurately reproduces the clinical and pathological features of TARV-induced reoviral arthritis.
• This model is suitable for future research on TARV pathogenesis and the efficacy of reoviral vaccines.
• TARV transmission to naive birds is efficient, highlighting the importance of biosecurity measures.