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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, Mariposa, Madera and Tulare County, CA
Outbreak Identifier: 5645
Alert ID: 3464
October 31, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food & Agriculture

Number Suspected: 13; 
Number Exposed: Unknown; 
Comments: VSV Situation Report 10/31/2023 Briefing Since the last situation report (10/25/2023), there have been 15 new VSV-affected premises identified (2 confirmed positive, 13 suspect) in California. All confirmed cases to date have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: California • Fresno County – 2 new confirmed positive small backyard cattle premises and 9 new suspect equine premises. Additionally, 1 previously reported suspect equine premises has now been confirmed positive. • Madera County – 2 new suspect equine premises • Mariposa County – 2 new suspect equine premises • Since the last situation report (10/25/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 6 premises in Fresno County and 3 premises in Tulare County. • Counties with current VSV quarantines: Fresno, Madera, Mariposa, and Tulare Counties. Since the start of the outbreak (5/17/2023), 251 VSV-affected premises have been identified (81 confirmed positive, 170 suspect) in 3 states, California, Nevada, and Texas. Two hundred forty-four (244) of these premises have had only equine species clinically affected, five (5) premises had only clinically affected cattle (Fresno County, San Diego County, and Santa Barbara County, California), one (1) premises had both equine and cattle clinically affected (Fresno County, California), and one (1) premises had clinically affected rhinoceros (San Diego County, California). California has identified 248 affected premises (78 confirmed positive, 170 suspect) in 12 counties (Fresno, Los Angeles, Madera, Mariposa, 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 251 total VSV-affected premises, 218 premises have completed the quarantine period with no new clinical cases and have been released from quarantine. Thirty-three (33) premises remain quarantined in California. Additional information is accessible at the following link: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/equine/vsv/vesicular-stomatitis


Previous Alerts: 3450, 3436, 3413, 3401, 3376, 3350, 3314, 3282, 3263, 3210, 3174, 3152, 3145, 3126, 3115, 3111, 3099, 3090, 3085, 3071, 3066, 3060