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
Riverside County, CA
Outbreak Identifier: 5541
Alert ID: 2940
March 22, 2023
Outbreak Update

California Department of Food and Agriculture

Number Confirmed: 2; 
Number Exposed: 600; 
Age: 12; Gender: Mare; Breed: Argentinian Polo Horse; Usage: Polo; Onset of Clinical Signs: 3/19/2023
Clinical Signs: mild neurologic; Confirmation Date: 3/21/2023; Horse Status: Affected And Alive 
Comments: A 12-year-old Argentinian polo horse mare displaying mild neurological signs has been confirmed positive for EHM secondary to EHV-1 (non-neuropathogenic strain). The mare was immediately isolated at the onset of clinical signs and is currently alive and under veterinary supervision. Out of an abundance of caution following the confirmation of ongoing viral presence on the premises, the entire facility with 600 horses onsite, previously under voluntary quarantine, has been placed under mandatory quarantine with twice daily temperature monitoring and enhanced biosecurity measures in place. All polo activities in the surrounding area remain voluntarily postponed until further notice. CDFA was onsite, and will continue to closely and actively monitor the situation. 
Previous Alerts: 2936