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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.



Sacramento, Placer, Mariposa County, CA
Outbreak Identifier: 5645
Alert ID: 3541
December 26, 2023
Confirmed Case(s) - Official Quarantine

California Department of Food & Agriculture

Number Confirmed: 3; 
Number Suspected: Unknown; 
Number Exposed: Unknown; 
Comments: VSV Situation Report 12/26/2023. Since the last situation report (12/19/2023), there have been 3 new VSV-affected premises identified (3 confirmed positive) in California, including a new affected county, Sacramento County. All confirmed cases to date have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: California • Placer County – 2 new confirmed positive equine premises • Sacramento County (New Infected County) – 1 confirmed positive equine premises • Additionally, since the last situation report (12/19/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 1 premises in Mariposa County and 1 premises in San Joaquin County. Counties with current VSV quarantines: Mariposa, Placer, and Sacramento Counties. Since the start of the outbreak (5/17/2023), 317 VSV-affected premises have been identified (97 confirmed positive, 220 suspect) in 3 states, California, Nevada, and Texas. Three hundred seven (307) 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 314 affected premises (94 confirmed positive, 220 suspect) in 19 counties (Fresno, Inyo, Kings, Los Angeles, Madera, Mariposa, Merced, Orange, Placer, Riverside, Sacramento, San Bernardino, San Diego, San Joaquin, 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 317 total VSV-affected premises, 312 premises have completed the quarantine period with no new clinical cases and have been released from quarantine. Five (5) premises remain quarantined in California. 

Additional information can be found at the following link: https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/animal-disease-information/equine/vsv/vesicular-stomatitis


Previous Alerts: 3535, 3525, 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