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.

Madera, Fresno, Tulare Counties, CA
Outbreak Identifier: 5645
Alert ID: 3436
October 22, 2023
Confirmed Case(s) - Official Quarantine


VSV Situation Report 10/20/2023 Briefing

Since the last situation report (10/13/2023), there have been 12 new VSV-affected equine premises (3 confirmed positive, 9 suspect) identified in California, including a new affected county, Madera County.  All confirmed cases to date have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows:  


  • Fresno County – 9 new suspect equine premises
  • Madera County (New Infected County) – 1 confirmed positive equine premises
  • Tulare County – 2 new confirmed positive equine premises
  • Additionally, since the last situation report (10/13/2023), the following previously confirmed positive or suspect premises have been released from quarantine:  2 premises in Fresno County and 4 premises in Tulare County. 
  • Counties with current VSV quarantines:  Fresno, Madera, and Tulare Counties      

Nevada and Texas

  • No new confirmed positive premises have been identified.

Since the start of the outbreak (5/17/2023),228 VSV-affected premises have been identified (74 confirmed positive, 154 suspect) in 3 states, California, Nevada, and Texas.  Two hundred twenty-four (224) of these premises have had only equine species clinically affected, three (3) premises have had clinically affected cattle (San Diego County and Santa Barbara County, California), and one (1) premises has had clinically affected rhinoceros (San Diego County, California). 

California has identified 225 affected premises (71 confirmed positive, 154 suspect) in 11 counties (Fresno, Los Angeles, Madera, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, Tulare, and Ventura Counties).  Texas identified 2 affected premises (2 confirmed positive) in 2 counties (Maverick and Shackelford Counties).  Nevada identified 1 affected premises (1 confirmed positive) in 1 county (White Pine County, Nevada). 

Of the 228 total VSV-affected premises, 209 premises have completed the quarantine period with no new clinical cases and have been released from quarantine.  Nineteen (19) premises remain quarantined in California. 

Additional information and maps of the affected area are contained in the situation reportwhich 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: 3413, 3401, 3376, 3350, 3314, 3282, 3263, 3210, 3174, 3152, 3145, 3126, 3115, 3111, 3099, 3090, 3085, 3071, 3066, 3060