🐴Equine Alert

EHV-1 Outbreak 2025: What Horse Owners Need to Know

An outbreak of Equine Herpesvirus-1 (EHV-1) has been spreading across multiple states since early November 2025. The outbreak has been traced to horses that attended the WPRA World Finals and Elite Barrel Race in Waco, Texas on November 5-9, 2025.

Here's what horse owners need to know to protect their animals.

Current Situation

As of mid-December 2025, confirmed cases have been reported in Texas, Oklahoma, Louisiana, Colorado, New Mexico, Arizona, South Dakota, and Washington. Many of these cases have developed into Equine Herpesvirus Myeloencephalopathy (EHM), the neurologic form of the disease.

Several major events have been canceled or postponed, including the BFA World Championships at Lazy E Arena and numerous NBHA-sanctioned events.

You can track the current outbreak status on our outbreak map or view state-by-state alerts.

What is EHV-1?

Equine Herpesvirus-1 is a common virus in horse populations worldwide. Most horses are exposed to EHV-1 by age two and carry the virus in a latent (dormant) state for life.

EHV-1 typically causes mild respiratory illness. However, some strains can cause:

  • Respiratory disease — fever, nasal discharge, coughing, lethargy
  • Abortion — in pregnant mares
  • Neurologic disease (EHM) — the most serious form, affecting the brain and spinal cord

The neurologic form is what makes this outbreak particularly concerning.

Symptoms to Watch For

Monitor your horses closely, especially if they've attended any events or been exposed to horses that have traveled recently.

Early signs:
  • Fever above 101.5°F (take temperatures twice daily)
  • Nasal discharge
  • Lethargy or reduced appetite
  • Coughing
Neurologic signs (EHM):
  • Hind-end weakness or wobbling
  • Leaning against walls for support
  • Urine dribbling or inability to urinate
  • Difficulty standing
  • Dog-sitting posture

If you notice any of these signs, isolate the horse immediately and contact your veterinarian.

How EHV-1 Spreads

The virus spreads through:

  • Direct contact — nose-to-nose contact between horses
  • Aerosol droplets — coughing and snorting (can travel up to 30 feet)
  • Contaminated objects — shared water buckets, feed tubs, tack, grooming tools
  • People — on hands, clothes, and boots

Horses can shed the virus before showing symptoms, which is why outbreaks at large events spread so quickly.

Quarantine Guidelines

If your horse attended an affected event or has been exposed to a horse that did:

  • Isolate immediately — keep at least 30 feet from other horses
  • Monitor temperature twice daily — fever often appears before other symptoms
  • Quarantine for 21 days minimum — this is the standard recommendation
  • Do not share equipment — separate buckets, tack, and tools
  • Practice strict biosecurity — change clothes and wash hands between horses

State veterinarians may issue official quarantine orders for confirmed cases.

Should You Cancel Travel Plans?

This is the question many horse owners are asking. Consider:

  • Where are you going? Check our outbreak map to see if there are active cases in that area
  • What type of event? Large gatherings with horses from multiple states carry higher risk
  • Is your horse vaccinated? Vaccination doesn't prevent EHM but may reduce severity and shedding
  • Can you quarantine when you return? If you can't isolate your horse for 21 days after returning, reconsider traveling

When in doubt, consult your veterinarian for guidance specific to your situation.

Biosecurity Best Practices

Whether or not you travel, now is a good time to tighten up biosecurity:

  • Quarantine new arrivals for 21 days before introducing them to your herd
  • Take temperatures daily during high-risk periods
  • Don't share equipment at events — bring your own buckets and tools
  • Wash hands between handling different horses
  • Ask about health status before allowing horses onto your property
  • Stay informed — monitor outbreak reports for your area

Vaccination

There is no vaccine that prevents EHM specifically. However, EHV-1 vaccines can help reduce:

  • Severity of respiratory disease
  • Viral shedding (reducing spread)
  • Risk of abortion in pregnant mares
Important: Do not vaccinate horses that have already been exposed or are showing symptoms. For healthy, unexposed horses, consult your veterinarian about whether a booster is appropriate.

Resources

Stay Informed

The situation is evolving. We update our outbreak data daily based on reports from the Equine Disease Communication Center.

View Current Outbreak Map →