Sacramento County EHV Quarantine Released

Sacramento County EHV Quarantine Released

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

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

A Sacramento County, California, facility has been released from a quarantine put in place after a horse residing there tested positive for equine herpesvirus-1 (EHV-1).

The California Department of Food and Agriculture (CDFA) reported April 28 that a 15-year-old Warmblood mare “initially showed signs of colic on Friday, April 21, and was transported to a veterinary clinic for veterinary care. While in isolation at the veterinary clinic, the mare started displaying neurologic signs, became recumbent, and was subsequently euthanized due to the severity of signs. Quarantine biosecurity measures were immediately implemented at the home premises.

“With neurologic signs and detection of EHV-1, this horse meets the case definition for an equine herpesvirus myeloencephalopathy (EHM) case, which is reportable and actionable in the state of California,” the CDFA continued. “CDFA issued a quarantine for 31 exposed horses which requires implementation of biosecurity measures including twice daily temperature taking and observation of horses. No exposed horses have displayed signs of disease.”

On May 5, the CDFA reported that “as no additional cases have been identified since the removal of the positive index equine herpesvirus myeloencephalopathy horse on April 21, 2017, the Sacramento County premises has been released from quarantine.”

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 EHM (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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