New Mexico EHV-1: Case Count Rises to 61

New Mexico EHV-1: Case Count Rises to 61

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. 10 that 62 horses have now tested positive for equine herpesvirus-1 (EHV-1) in connection with an outbreak that began last month at Sunland Park Racetrack.

The NMLB reported that three horses were released from the isolation barn on Feb. 9, and eight exposed barns have been returned to nonexposed status. Further, the NMLB said that Sunland Park along with three local training centers—Frontera Training Center, Jovi, and Lazy S—remain in the quarantine perimeter.

“Biosecurity measures among horsemen and women are still necessary, such as taking temperatures twice a day, handwashing, washing/disinfecting anything a horse has touched or could touch, etc,” the NMLB said.

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.

Editor's Note: This article was updated to reflect the most recent case numbers provided by the NMLB.

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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