California EHV-1: Euthanized Horse Necropsy Complete

No new cases of neurologic equine herpesvirus (NEHV-1) have been confirmed since Jan. 20 in connection with the current outbreak in Orange County, Calif., according to a statement from the California Department of Food and Agriculture (CDFA). The total number of cases stands at 11.

Additionally, a necropsy has been completed on the lone horse to perish as a result of the outbreak: "A confirmed positive horse became recumbent and was euthanized on Jan. 18, 2012," the statement read. "The necropsy results indicate that it is highly unlikely that the recumbency was due to the (neurologic) EHV-1 infection."

The CDFA provided no further information as to a possible cause of recumbency.

The rest of the affected horses are reportedly recovering. One--the index case--has exhibited neurologic signs. "All other confirmed NEHV-1 positive horses displayed respiratory symptoms, limb edema (fluid swelling), and/or fever," the statement read.

The single facility remains under quarantine.

Although it's not transmissible to humans, EHV-1 is highly contagious among horses and camelids, and it is generally passed from horse to horse via aerosol transmission (when affected animals sneeze/cough) and contact with nasal secretions. The disease can cause a variety of ailments in equines, including rhinopneumonitis (a respiratory disease usually found in young horses), abortion in broodmares, and myeloencephalopathy (EHM, the neurologic form).

Myeloencephalopathy is characterized by fever, ataxia (incoordination), weakness or paralysis of the hind limbs, and incontinence. Should a horse with potential EHV-1 exposure display any of the aforementioned clinical signs, a veterinarian should be called to obtain samples and test for the disease. will continue to provide updated information as it becomes available.

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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