By KIMBERLY LOUSHIN
On Tuesday, Nov. 25, the American Association of Equine Practitioners (AAEP) and the Equine Disease Communications Center (EDCC) hosted a webinar to address the current equine herpesvirus-1 (EHV-1) outbreak, which was first reported Nov. 18 in Texas following the Woman’s Professional Rodeo Association (WPRA) World Finals and Elite Barrel Race, Nov. 5-9. At time of publication, there are eight states affected by the outbreak with 34 confirmed cases. A separate case of equine herpesvirus myeloencephalopathy (EHM), the neurologic form of the disease, has been reported in Maryland, but it is unrelated to the outbreak that originated in Texas.
During the webinar, the speakers, which included Dr. Krista Estell, an infectious disease specialist at Virginia Tech’s Marion DuPont Scott Equine Medical Center; Dr. Katie Flynn, USEF’s senior veterinarian on equine health and biosecurity; and Texas state veterinarian, Dr. Lewis “Bud” Dinges, emphasized the importance of consulting their own veterinarian from the onset of any symptoms and throughout treatment as all cases are different.
The equine herpesvirus is highly contagious and can be transmitted by horse-to-horse contact, through the air, or by living on surfaces or humans who come in contact with the virus. When exposed to light and air, the virus doesn’t last long, but in wet or shady areas, it can persist up to 21 days, Estell said. Once the virus is in the bloodstream, the incubation period can last from two to 10 days, but the initial fever or lethargy can be easy to miss. The onset of any neurologic symptoms can take even longer.
Estell stressed the importance of knowing your horse’s regular temperature, but shared that anything above 101.5 Fahrenheit is considered a fever and warrants a call to your veterinarian.
While there are three different viral strains of the disease, Estell said veterinarians have determined that all strains can cause neurological disease. While there are some hallmark signs of neurological infection such as ataxia, urine dribbling and hind-end weakness, Estell said the clinical signs are variable based on the damage the virus causes to the brain or spinal cord and where resulting blood clots occur.
Flynn focused on biosecurity measures and emphasized the importance of having a quarantine plan in place before an outbreak, such as having movable panels set up in an open area or arena could work, She also spoke of the importance of following good biosecurity practices all the time–not just during an outbreak–like not letting horses touch hoses, not using the same nose rag on each horse, and using appropriate disinfectants for the surface in question that is meant to be used in situations with lots of organic material like manure.
The full 90-minute webinar is available here.
