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
Stanislaus County, CA
Outbreak Identifier: 5630
Alert ID: 3041
June 02, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 5; 
Number Exposed: 28; 
Facility Type: Private Facility; 
Age: 25; Gender: Gelding; Breed: Quarter Horse (QH); 
Clinical Signs: Fever, mild neurological signs; Confirmation Date: 6/1/2023; Horse Status: Affected And Alive; 
Comments: A 25-year-old Quarter Horse gelding in Stanislaus County displaying mild neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on June 1st. The gelding is alive and under veterinary care. Additionally, 4 (four) other horses displaying fever or edema only from the index the premises have also been confirmed positive for EHV-1. The EHV-1 positive horses and 28 potentially exposed horses at the home premises in Stanislaus County have been quarantined with enhanced biosecurity measures implemented. CDFA was onsite, and will continue to actively monitor the situation. For more information and updates, go to: https://www.cdfa.ca.gov/ahfss/Animal_Health/equine_herpes_virus.html;

For more information, go to: https://www.equinediseasecc.org/equine-herpesvirus