By C.J. (Kate) Savage, BVSc(Hons), MS, PhD, Dipl. ACVIM, WEVA Junior Vice President

Veterinarians and horse owners should remain vigilant for two relatively new horse health challenges: equine rhinitis A (ERAV) and B (ERBV) viruses and coronavirus.

In the past, these viruses have been rarely specifically implicated as the cause of disease because, until recently, veterinarians have not typically requested them on a panel; instead, they concentrated on the more common and clinically important diseases, such as equine herpesvirus types 1 and 4 and influenza virus.

Previously, ERAV and ERBV were rarely implicated as causes of equine disease. Equine rhinitis A appears to cause mild to moderate respiratory disease, with or without nasal discharge, pharyngitis (inflammation of the pharynx), and coughing. Horses shed ERAV in urine, feces, and respiratory secretions, whereas veterinarians have not recognized urine and fecal shedding of ERBV. In 2012 a conditionally licensed ERAV vaccine became available in the United States. Equine rhinitis viruses also have some zoonotic potential, meaning they are communicable to people, but the risk of human infection appears low