Equine Herpesvirus-1 (EHV-1) Update May 20, 2011: Texas Animal Health Commission (TAHC) officials are continuing to trace exposed horses that attended the National Cutting Horse Association (NCHA) Western National Championships event that ended on May 8 in Ogden, Utah that were potentially exposed to Equine Herpesvirus-1( EHV-1). There are now 25 known horses in Texas that attended the event and 336 more cohorts (stablemates) of the 25 that are currently being held under movement restrictions across the state. The good news is that no new cases have been reported today. Texas still only has one confirmed case and one suspect case reported. The epidemiological investigation continues however, and Texas horse owners must be vigilant of the possibility that exposed horses may still be incubating the disease.
TAHC continues to suggests that horse owners closely evaluate the risk of participating in upcoming events scheduled for this weekend and/or co-mingling their horses with other horses and equipment (trailers) of unknown history. Because the incubation period is usually about 4-6 days or less, even a one week voluntary stop movement may be enough to nip the cycle of transmission between horses before it grows in scope. The TAHC will re-evaluate this position after analyzing new case data or other epidemiological information that may be disclosed over the weekend.
Horse owners should contact event organizers in advance to ensure that scheduled events have not been cancelled. Some other states have established emergency rules for entry as a result of this situation, so if interstate travel is planned, owners and/or veterinarians writing health certificates should check in advance to ensure they meet all entry requirements. Finally, it is recommended that all newly purchased horses or introduced horses to a premise should be isolated to help.