Editor’s note: This story was updated Nov. 24 to reflect current case numbers.
SALEM, Ohio — Local stables and arenas in the tri-state area are tightening up their safety measures as concerns grow over an outbreak of equine herpesvirus myeloencephalopathy, or EHM.
The outbreak traces back to the Women’s Professional Rodeo Association World Finals and Elite Barrel Race event held in Waco, Texas, from Nov. 5 to Nov. 9. As of Nov. 24, the Equine Disease Communication Center has confirmed 21 connected cases.
EHM is a highly contagious and potentially fatal neurological condition linked to the equine herpesvirus-1. So far, cases of EHM have been identified in Texas, Oklahoma, Louisiana, Colorado and New Mexico. Additional cases of EHV-1 without neurological signs tied to the Waco-Texas outbreak have been detected in Washington and Arizona.
At least two horses in Texas have been euthanized as a result of this infection.
Some local facilities aren’t waiting for the virus to strike any closer. Garwood Arena in Columbiana, Ohio, announced it would be canceling several upcoming events due to the outbreak. E&H Cattle Company, in Dover, Ohio, also decided to cancel the barrel racing portion of its Nov. 21 rodeo, though the rest of the event is moving forward.
Buckhorn Ranch Arena in West Sunbury, Pennsylvania, has postponed several events in its Winter Barrels series, shifting its focus to dates later in December, and closed its facility to haul-ins until further notice. Bullride Mania Rodeo Company likewise canceled its barrel racing, breakaway roping and team roping competitions planned for finals beginning Nov. 21 in Harrisburg.
The West Virginia Department of Agriculture issued a statement on Nov. 20 saying it, too, is monitoring the multi-state outbreak. In its release, the department encouraged anyone who owns or manages a boarding or training barn — especially those whose horses travel to local, regional or national competitions — to take precautions.
“It behooves everyone who owns, operates or manages a boarding or training facility in which clientele horses participate in organized competitive events, whether local, regional or with national exposure, to take precautions and have a general biosecurity plan for dealing with signs of EHM,” WVDA wrote.
The Ohio Department of Agriculture stated that there are no confirmed cases of EHV/EHM in Ohio, but the ODA is coordinating with affected states and awaiting trace information from Texas and Oklahoma. EHV/EHM is a reportable disease in Ohio.
Exposed horses should be isolated for 21 days after last-known exposure and isolation should include restricted access to other horses, avoiding shared equipment or personnel, and using appropriate protective barriers, according to the Ohio State University Veterinary Medical Center.
A case of EHV-1 was confirmed in Madison County, Ohio on Nov. 23, but it was not linked to the Waco, Texas, outbreak. A case of EHV-4, a less severe variant of equine herpesvirus, was detected in eastern Pennsylvania on Nov. 23.
What to do
Equine herpesvirus commonly causes respiratory disease, but some strains cause outbreaks of the neurological disease, known as EHM. Symptoms of EHV-1 can vary widely. Some horses may show mild signs like nasal discharge, a fever of 102.5 F or greater and coughing.
Other symptoms include becoming lethargic or developing worsening neurological issues, which occur as a result of a lack of blood flow and resulting damage to the brain or spinal cord.
Symptoms can include stumbling, incoordination, loss of tail tone, hind-limb weakness, head tilt, difficulty standing and urine dribbling.
In most cases, 60% to 70% of affected horses recover with treatment and supportive care, according to the Equine Disease Communication Center, but veterinary evaluation and isolation of exposed or affected horses is crucial.
