The extent of this outbreak is not yet fully known, and the situation is developing rapidly. Symptoms in infected horses appear to be acute with rapid progression and high clinical severity. Reports of an increasing number of deaths in horses suspected of having EHM are concerning and underscore the need for proactive actions to curb the spread of this disease.

All affected horses attended the 2025 WPRA World Finals and Elite Barrel Race event in Waco, Texas Nov. 5-9. The two confirmed cases in Oklahoma also attended the BFA World Championship at Lazy E Arena in Guthrie, Okla., that was scheduled for Nov. 17-22. Due to the confirmed positive cases, this event was canceled, and remaining participants were sent home.

Protocols for infected horses include:
• Isolating the horses that attended the event for at least three weeks
• Having the temperature of returning horses monitored twice daily for at least 14 days after the last known exposure. Fever greater than 101.5 degrees may be the first indicator of disease.
• Clean and disinfect tack, boots, equipment and grooming supplies. Wash hands.
• If fever or other signs consistent with EHM develop, contact your veterinarian.
• When feeding and doing chores or work with the returning horses last, wear boots and coveralls, and remove them before working with your other horses.

EHV-1 primarily affects the respiratory system of horses but can also cause severe neurological disease and death. Symptoms include fever, coughing, nasal discharge and loss of balance. The virus is transmitted through body fluids. It is highly contagious among horses but does not affect humans.

If anyone suspects their horse has been exposed, they should contact their veterinarian. The state is asking that confirmed cases be reported by calling 919.707.3250.