Equine Rotavirus Study Guide

Overview and Clinical Importance

Equine rotavirus (ERV) is the most common cause of infectious diarrhea in foals worldwide and represents a high-yield topic for the NAVLE. This double-stranded RNA virus of the family Reoviridae causes significant morbidity on breeding farms, with up to 50% of foals contracting the virus and morbidity rates exceeding 70% during outbreaks. While mortality is typically low (less than 1% with appropriate treatment), the economic impact is substantial due to intensive supportive care requirements, labor costs, and biosecurity measures.

The virus primarily affects foals less than 6 months of age, with the most severe disease occurring in neonates under 2 weeks old. In 2021, a novel Equine Rotavirus Group B (ERVB) was identified in Kentucky, expanding our understanding beyond the traditionally recognized Group A rotaviruses (ERVA). This discovery has significant implications for diagnosis and prevention strategies.

Etiology and Classification

Viral Characteristics

Rotaviruses belong to the genus Rotavirus within the family Reoviridae. The name derives from the Latin word "rota" (wheel) due to the characteristic wheel-like appearance under electron microscopy. Key structural features include: