Breaking News
National Equine Health Stakeholder Call-October 2026
Learn More

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.



1 Week
2 Weeks
1 Month
2 Months
3 Months
3+ Months
No Results

The color range is based off of the selected End Date. If the End Date doesn't have a value it will use Today's Date.

San Mateo County, CA
Outbreak Identifier: 5069
Alert ID: 2423
February 16, 2022
Outbreak Update

California Department of Food and Agriculture

Number Confirmed: 18;
Number Suspected: 5;
Number Exposed: 300;
Facility Type: Boarding Facility;
Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Gender: Gelding; Onset of Clinical Signs: 2/10/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Age: 4; Gender: Gelding; Breed: Thoroughbred (TB); Onset of Clinical Signs: 2/12/2022;
Clinical Signs: Fever; Confirmation Date: 2/15/2022; Horse Status: Affected And Alive; Vaccination Status: Vaccinated;
Notes: Update 2/16/22: Previous Alert IDs: 2405, 2406, 2408, 2410, 2415: Four (4) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 15th, and have been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and sixteen (16) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.;