Outbreaks | Equine Disease Communication Center

Updates on current disease outbreaks are listed here as they occur and will include the date listed, disease name, location and current status. Specific premises will not be named but the general location by town, county and state will be listed. When locations, events or horses are at risk they will be listed. Updates will be posted as they are received.

Disease

Outbreak States

Start Date

End Date

Equine Herpesvirus- Neurologic

Santa Barbara County, CA

Outbreak Identifier: 6777

Alert ID: 4271

March 21, 2025

Confirmed Case(s) - Official Quarantine

Source: California Department of Food and Agriculture

Number Confirmed: 1;
Number Exposed: 41;
Number Euthanized: 1;

Horse 1:
Age: 16; Gender: Mare; Breed: Pony; Onset of Clinical Signs: 3/17/2025; Confirmation Date: 3/19/2025; Horse Status: Euthanized;

Comments: A 16-year-old Pony mare from Santa Barbara County displaying neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1). The mare was euthanized due to the severity of clinical symptoms. The mare had recently attended a show but did not show any clinical symptoms until after the event concluded. Forty-one (41) potentially exposed horses at the home premise in Santa Barbara County were quarantined by CDFA with enhanced biosecurity measures implemented. CDFA will continue to actively monitor the situation. This premises has no known epidemiological link to the Ventura County EHM premises.;

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