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.

Riverside County, San Bernardino County, San Diego County, Los Angeles County, Orange County, CA
Outbreak Identifier: 5645
Alert ID: 3066
June 16, 2023

Since the last situation report (6/9/2023), there have been 18 new VSV-affected premises identified (3 confirmed positive, 15 suspect) in California with five counties currently affected:  Los Angeles, Orange, Riverside, San Bernardino, and San Diego Counties.  To date, all confirmed cases have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows:  


  • Riverside County – 1 new confirmed positive and 5 new suspect equine premises
  • San Bernardino County – 1 new suspect equine premises
  • San Diego County – 2 new confirmed positive premises (1 equine, 1 cattle) and 9 new suspect equine premises
  • Since the last situation report (6/9/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 6 equine premises in Riverside County and 12 equine premises in San Diego County.   

Since the start of the 2023 outbreak on May 17th, 96 VSV-affected premises have been identified (33 confirmed positive, 63 suspect) in 2 states, California and Texas.  Ninety-three (93) of these premises have had only equine species clinically affected, two (2) premises have had clinically affected cattle (San Diego County, California), and one (1) premises has had clinically affected rhinoceros (San Diego County, California). 

California has identified 95 affected premises (32 confirmed positive, 63 suspect) in 5 counties (Los Angeles, Orange, Riverside, San Bernardino, and San Diego Counties).  Texas has identified 1 affected premises (1 confirmed positive) in 1 county (Maverick County, Texas).  

Of the 96 total VSV-affected premises, 28 premises have completed the quarantine period with no new clinical cases and have been released from quarantine.  Sixty-eight (68) premises remain quarantined.  
Previous Alerts: 3060