Horse owners in Arizona are on high alert due to the spread of Equine Herpesvirus (EHV-1), which originated at major equestrian events in Texas and Oklahoma and has now reached Arizona, with confirmed cases in Maricopa and Pinal counties. The virus poses serious health risks to horses, including respiratory illness, neurological symptoms, and abortion in pregnant mares. In response, many equine events across the state, such as the Desert Classic Horse Show, have been canceled or postponed, and strict biosecurity measures are being enforced to prevent further spread.

Veterinarians recommend quarantining new horses, disinfecting tack, water buckets, and other equipment, and monitoring horses’ temperatures twice daily. Humans can act as mechanical carriers, spreading the virus via contaminated clothing or tools. All equines—including horses, donkeys, mules, llamas, and alpacas—are at risk, and owners should watch for symptoms like fever, nasal discharge, weakness, and neurological signs. Prompt quarantine and veterinary consultation are advised if infection is suspected.