Equine herpesvirus-1 spreads in nasal discharge or aerosol droplets. Horses can also contract the virus via contaminated surfaces such as stalls, water, feed, tack, transportation vehicles, or people’s contaminated hands and clothing from being around another affected horse.

This relatively common virus’ incubation period ranges from two to 10 days. Clinical signs of respiratory EHV-1 infection include fever, nasal discharge, and lethargy/depression. Infected horses can shed the virus even when showing no clinical signs.

Disease caused by EHV-1 can be mild or can be more severe, potentially resulting in late-term abortion in pregnant mares and/or severe neurologic disease. Equine herpesvirus myeloencephalitis, EHV’s neurologic form, is rare