New Mexico EHV-1: Case Count Rises to 44

New Mexico EHV-1: Case Count Rises to 44

In many horses, fever is the only sign of EHV-1 infection, which can go undetected.

Photo: Stephanie L. Church, Editor-in-Chief

The New Mexico Livestock Board (NMLB) reported Feb. 3 that additional horses have tested positive for equine herpesvirus-1 (EHV-1), bringing the total case count to 44. Most of the affected horses reside at Sunland Park racetrack, but the most recent round of testing identified several EHV-1 positive-horses at a nearby training center.

“To date, 44 horses have been confirmed positive for EHV-1 on nasal swab and/or whole blood,” the statement read. “These horses are from 19 different barns within Sunland Park racetrack. Two positive horses are from an adjacent training facility (Frontera) close to the Sunland Park racetrack. Frontera has always been included in the original quarantine perimeter.

“Of these 44 horses, five have been euthanized for progressive neurologic signs,” the NMLB reported.

No movement of horses is being allowed in or out of Sunland Park. Officials with the NMLB, New Mexico Racing Commission, and Sunland Park will continue to work together to resolve the issue, the statement said.

Health Alert: Equine Herpesvirus

Herpesvirus is highly contagious among horses and can cause a variety of ailments in equids, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (the neurologic form). In many horses, fever is the only sign of EHV-1 infection, which can go undetected.

In addition to fever, other common signs of EHV-1 infection in young horses include cough, decreased appetite, depression, and a nasal discharge. Pregnant mares typically show no signs of infection before they abort, and abortions usually occur late in gestation (around eight months), but can be earlier. Abortions can occur anywhere from two weeks to several months following infection with EHV-1.

Horses with the neurologic form usually have a fever at the onset of the disease and might show signs of a respiratory infection. A few days later, neurologic signs such as ataxia (incoordination), weakness or paralysis of the fore- and hind limbs, urine retention and dribbling, loss of tail tone, and recumbency (inability to rise) develop.

About the Author

Erica Larson, News Editor

Erica Larson, news editor, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

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