EHV-1 Confirmed in Los Angeles County, California

EHV-1 Confirmed in Los Angeles County, California

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

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

A Los Angeles County, California, horse is in quarantine after testing positive for equine herpesvirus-1 (EHV-1) earlier this month.

“A draft-cross gelding displaying neurologic signs has been confirmed positive for the non-neuropathogenic strain of equine herpesvirus-1,” the California Department of Food and Agriculture (CDFA) said in a Jan. 6 statement. “A small percentage of the non-neuropathogenic-infected horses can display neurologic signs compatible with equine herpes myeloencephalopathy which is a reportable disease in California. The positive horse has been quarantined and isolated.”

The CDFA said no horses have entered or left the affected premises since last September, and all exposed horses are being monitored. As of Jan. 15, no new cases had been reported.

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. 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.

The virus is spread by direct horse-to-horse contact or through contact with objects contaminated with the virus.

The CDFA continues to monitor the situation in California.

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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