Disease Alerts

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.



Equine Herpesvirus- Neurologic
Los Angeles County, CA
Outbreak Identifier: 5381
Alert ID: 2763
October 06, 2022
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 1
Number Exposed: 45
Age: 33; Gender: Gelding; Breed: Quarter Horse (QH); Onset of Clinical Signs: 10/2/2022
Clinical Signs: fever, neurologic; Confirmation Date: 10/6/2022; Horse Status: Euthanized; Vaccination Status: Vaccinated
Comments: A 33-year-old Quarter Horse gelding in Los Angeles county displaying fever and neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on October 6th. The gelding was euthanized due to severity of clinical signs. CDFA was onsite to implement enhanced biosecurity on October 6th and forty-five (45) potentially exposed horses were quarantined. For additional information, go to: EHM Factsheet.