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.



Fresno, Madera, and Mariposa Counties County, CA
Outbreak Identifier: 5645
Alert ID: 3525
December 12, 2023
Outbreak Update

California Department of Food and Agriculture

Number Confirmed: 1; 
Number Exposed: Unknown; 
Comments: VSV Situation Report 12/12/2023. Since the last situation report (12/5/2023), there has been 1 new VSV-affected premises identified (1 confirmed positive) in California. All confirmed cases to date have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: California, Mariposa County – 1 new confirmed positive equine premises. Additionally, since the last situation report (12/5/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 3 premises in Fresno County, 6 premises in Madera County, and 1 premises in Merced County. Counties with current VSV quarantines: Fresno, Madera, and Mariposa Counties. Since the start of the outbreak (5/17/2023), 311 VSV-affected premises have been identified (92 confirmed positive, 219 suspect) in 3 states, California, Nevada, and Texas. Three hundred one (301) of these premises have had only equine species clinically affected, seven (7) premises had only clinically affected cattle (Fresno County, San Diego County, and Santa Barbara County, California), two (2) premises had both equine and cattle clinically affected (Fresno County and Mariposa County, California), and one (1) premises had clinically affected rhinoceros (San Diego County, California). California has identified 308 affected premises (89 confirmed positive, 219 suspect) in 16 counties (Fresno, Inyo, Kings, Los Angeles, Madera, Mariposa, Merced, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, Tulare, Tuolumne, 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 311 total VSV-affected premises, 307 premises have completed the quarantine period with no new clinical cases and have been released from quarantine. Four (4) premises remain quarantined in California. 

Additional information and maps are accessible at the following link: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/equine/vsv/vesicular-stomatitis


Previous Alerts: 3518, 3507, 3496, 3491, 3489, 3475, 3464, 3450, 3436, 3413, 3401, 3376, 3350, 3314, 3282, 3263, 3210, 3174, 3152, 3145, 3126, 3115, 3111, 3099, 3090, 3085, 3071, 3066, 3060