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.



Los Angeles County, CA
Outbreak Identifier: 5537
Alert ID: 2932
March 14, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 1
Number Suspected: Unknown
Number Exposed: 61
Facility Type: Private Facility 
Age: 19; Gender: Gelding; Breed: Saddlebred; Onset of Clinical Signs: 3/13/2023
Clinical Signs: Acute ataxia and urine dribbling.; Confirmation Date: 3/14/2023; Horse Status: Euthanized
Comments: A 19-year-old Saddlebred gelding at a private boarding facility in Los Angeles County displaying acute neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on March 14th. The gelding was euthanized due to severity of clinical signs. The index case had no recent show or travel history in the past two weeks. CDFA was onsite at the index premises in Los Angeles County, and sixty-one (61) additional horses were quarantined with enhanced biosecurity measures implemented. For more information and updates, go to https://www.cdfa.ca.gov/ahfss/Animal_Health/equine_herpes_virus.html.

For additional information about EHM, go to https://www.equinediseasecc.org/equine-herpesvirus.