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
San Luis Obispo County, CA
Outbreak Identifier: 5626
Alert ID: 3036
May 30, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food and Agriculture

Number Confirmed: 1; 
Number Exposed: 42; 
Facility Type: Boarding Facility; 
Age: 19; Gender: Mare; Breed: Paint; Usage: Pleasure Riding; Onset of Clinical Signs: 5/19/2023;
Clinical Signs: Ataxia, urine dribbling and bladder atony.; Confirmation Date: 5/26/2023; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Comments: May 30, 2023: A 19-year-old Paint mare in San Luis Obispo county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on May 26th. The mare is currently quarantined under veterinary care at an offsite hospital, also in San Luis Obispo County. Forty (40) potentially exposed horses on the mare’s home premises have also been quarantined. Additionally, out of an abundance of caution, two (2) horses at the offsite veterinary hospital have been quarantined due to low possibility of exposure. The index horse has not had any recent show or travel history. CDFA was onsite to implement enhanced biosecurity on both premises and will monitor the situation closely. No additional clinical signs or cases have been reported since confirmation. 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