Equine Coronavirus Enteritis Study Guide

Overview and Clinical Importance

Equine coronavirus (ECoV) is an emerging enteric pathogen of adult horses that has been reported with increasing frequency since 2010. Unlike other species where coronaviruses primarily cause respiratory disease, ECoV in horses predominantly targets the gastrointestinal tract. This single-stranded, positive-sense RNA virus belongs to the Betacoronavirus genus and is genetically related to bovine coronavirus (BCoV).

ECoV is clinically significant because it causes outbreaks at equine facilities with high morbidity rates (10-83%), although mortality is generally low. The disease is characterized by fever, anorexia, and lethargy, with less frequent gastrointestinal signs such as colic and diarrhea. Understanding this emerging pathogen is essential for the NAVLE, particularly regarding differential diagnosis of adult horse enterocolitis.

Etiology and Viral Characteristics

Equine coronavirus is a member of the family Coronaviridae, subfamily Coronavirinae, genus Betacoronavirus. The virus is characterized as a single-stranded, positive-sense, non-segmented, enveloped RNA virus. ECoV is closely related to bovine coronavirus (BCoV) and shares significant genetic homology with human coronavirus strains OC43 and HKU1.