EHV-1 Disease Guidelines

As riders ourselves, we know how unsettling situations like the recent EHV-1 outbreak can be. Staying informed—and staying in close communication with your veterinarian—is essential. Here’s what you need to know about the virus, the symptoms to watch for, and the biosecurity practices that can help protect your horse.

Equine Herpesvirus Type 1 is a contagious viral disease that affects horses of all ages and breeds. The virus can cause respiratory illness, fever, nasal discharge, and in pregnant mares it can cause miscarriage. In some cases, the virus affects the nervous system in a form known as Equine Herpesvirus Myeloencephalopathy which can be far more serious. Horses that develop the neurologic Equine Herpesvirus Myeloencephalopathy form may show hind limb weakness, loss of coordination, difficulty standing, or complete inability to rise.¹

During a recent outbreak in Texas, veterinarians reported an increase in horses showing the respiratory and neurologic forms of the disease.² The event prompted state level alerts and recommendations for increased monitoring and biosecurity. Although past outbreaks have occurred across the United States, this most recent cluster serves as a reminder that the virus can spread quickly when horses gather for competition, training, sales or travel.

Horse owners should closely watch for early symptoms. These include:

• Fever, which often rises above 101 point five degrees Fahrenheit
• Nasal discharge
• Cough
• Loss of appetite
• Swelling of the legs
• Depression, or a sudden change in behavior.

Neurologic signs require immediate veterinary involvement and can include staggering, hind limb weakness, difficulty turning, dribbling urine, reduced tail tone, or an inability to stand without assistance.³ Any horse showing these signs should be isolated immediately.

The virus spreads through direct contact such as nose to nose touching and through aerosolized droplets from coughing or sneezing. It also spreads indirectly on shared equipment, grooming tools, buckets, clothing, and human hands.¹ Good sanitation practices are essential. Tack, grooming items, and stall tools should be disinfected regularly. Buckets should not be shared, and horses returning from events should be isolated for at least fourteen days.

Daily temperature monitoring is one of the most effective early detection tools. Owners should record temperatures at consistent times each day and track even small increases. If one horse in a barn shows signs of infection, all horses that traveled or made contact with outsiders should be monitored more closely.

Because the virus can remain latent and reactivate during times of stress, prevention depends on consistent management. Careful travel planning, minimizing unnecessary contact with unknown horses, and maintaining a clean and organized barn environment can help reduce risk. Working closely with a veterinarian ensures that any suspected case is addressed promptly.

The recent outbreak highlights how quickly the virus can move through equine communities. With vigilance and sound biosecurity, horse owners can protect their animals and limit further spread.

This article is intended educational purposes only and is not professional advice. Always consult with your veterinarian in matters of equine health.

Sources
¹ Barrel Racing
² KWTX
³ Horse and Rider