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.

Los Angeles County, Orange County, San Bernardino County, Riverside County, San Diego County, Ventura County, CA
Outbreak Identifier: 5645
Alert ID: 3085
June 30, 2023
Confirmed Case(s) - Official Quarantine

VSV Situation Report 6/30/2023

Since the last situation report (6/22/2023), there have been 10 new VSV-affected equine premises identified (2 confirmed positive, 8 suspect) in California.  There are six counties currently affected in California (Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura Counties). The one affected premises in Texas (Maverick County) was released from quarantine on 6/27/2023 and no new affected premises have been identified in Texas.  All confirmed cases have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows:  


  • Riverside County – 1 new confirmed positive and 3 new suspect equine premises.  Additionally, 1 previously reported suspect equine premises has been confirmed positive.  
  • San Bernardino County – 2 new suspect equine premises
  • San Diego County – 1 new confirmed positive and 3 new suspect equine premises.  Additionally, 1 previously released equine premises has been re-quarantined. 
  • Since the last situation report (6/22/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 6 premises in Riverside County, 1 premises in San Bernardino County, and 17 premises in San Diego County. 


  • No new confirmed positive or suspect premises have been identified.
  • The one previously confirmed positive equine premises in Maverick County has been released from quarantine.   

Since the start of the outbreak, 114 VSV-affected premises have been identified (39 confirmed positive, 75 suspect) in 2 states, California and Texas.  One hundred eleven (111) 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 113 affected premises (38 confirmed positive, 75 suspect) in 6 counties (Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura Counties).  Texas identified 1 affected premises (1 confirmed positive) in 1 county (Maverick County, Texas).  

Of the 114 total VSV-affected premises, 59 premises have completed the quarantine period with no new clinical cases and have been released from quarantine.  Fifty-five (55) premises remain quarantined. 

Additional information and maps of the affected area are contained in the attached situation report.  The situation report is posted publicly on the APHIS website and accessible at the following link:  https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/equine/vsv/vesicular-stomatitis
Previous Alerts: 3071, 3066, 3060