The entrance to McGee Park/San Juan County Fairgrounds off U.S. Highway 64, Lee Acres, New Mexico. (Scott Michlin/Special to the Tri-City Record)
The entrance to McGee Park/San Juan County Fairgrounds off U.S. Highway 64, Lee Acres, New Mexico. (Scott Michlin/Special to the Tri-City Record)

Horses were banned from McGee Park fairgrounds Thursday morning to help prevent the spread of the potentially fatal equine herpes virus, or EHV-1, which has caused outbreaks in several states.

On Tuesday, Texas and Oklahoma confirmed cases of a neurological disease linked to EHV-1 among horses that attended early November riding events. Horses traveling from New Mexico were also present at those events. Public health officials in numerous states are working to contain the virus and alert horse owners.

San Juan County followed suit Thursday morning.

“McGee Park will be closed to all equine activity due to EHV-1 until further notice,” according to an announcement on the county’s Facebook page. “This closure includes events, open riding, practices and all overnight stalls.”

“No cases that we are aware of in the county and we would like to keep it that way,” said San Juan County spokesman Devin Neeley.

Contact tracing linked horses at those events to seven New Mexico counties, the state livestock board said. Those counties are Doña Ana, Eddy, Santa Fe, De Baca, Roosevelt, Otero and Chaves.

The neurological disease linked to EHV-1 is known as equine herpes myeloencephalopathy, or EHM. Recovery rates range from 60% to 70% when treated, according to the Equine Disease Communication Center.

As of Friday, the center reported one confirmed EHM case in New Mexico. Texas and Oklahoma had seven and three EHM cases, respectively. Louisiana had three and Colorado had one. Oklahoma also reported one confirmed EHV-1 case.

“At this time we’re really just asking people to be cautious and not travel to any areas that had exposure,” said Dr. Samantha Holeck, New Mexico Livestock Board state veterinarian.

“The extent of this EHV-1 outbreak is not yet fully known,” the board said. “A concerning number of mortalities in horses suspected of having EHM have been reported in other states and the need for rapid and proactive actions to curb the spread is clear.”

The Equine Disease Communication Center said cases originated at the Women’s Professional Rodeo Association World Finals and Elite Barrel Race event held Nov. 5-9 in Waco, Texas.

Monitoring the spread of EHV-1

Owners of horses that may have been exposed to EHM should work with a veterinarian to establish biosecurity and monitoring plans, including:* Isolate horses that attended the event for at least two weeks.* Monitor returning horses’ temperature twice daily for at least 14 days after the last known exposure. A fever above 101.5 F is often the first indicator of EHV-1.* If a fever greater than 102.5 F or other signs of EHM develop, contact your veterinarian immediately.

Clinical signs of EHM* Lethargy, nasal discharge, eye discharge, swelling of the legs, lack of coordination, hindquarter weakness, leaning or resting against a surface to maintain balance, urine dribbling, biminished tail tone, penile paralysis, head tilt, abortion in pregnant mares.These signs are not specific to EHM; diagnostic testing is required to confirm infection. If you suspect exposure to EHV-1, contact your local veterinarian.To help prevent spread:* Wash hands and use sanitizer before and after working with horses.* Disinfect clothing and footwear before and after contact.* Wash and disinfect items such as feed and water buckets, grooming gear, saddles and other tack.* Avoid visiting other barns or facilities with horses.

Additional resources:https://www.aphis.usda.gov/livestock-poultry-disease/equine/herpesvirushttps://aaep.org/wp-content/uploads/2024/02/EHV1-4-guidelines-2021.pdfThe Equine Disease Communication Center reports cases submitted by veterinarians and state animal health officials. Veterinarians with confirmed or suspected EHM cases can submit a report at https://equinediseasecc.org/forms/report-outbreak.Sources: New Mexico Livestock Board and Equine Disease Communication Center