Breaking News
Survey Assess Horse Owner's Biosecurity Practices
Learn More
Learn More

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, San Luis Obispo County, Santa Barbara County, Ventura County, CA
Outbreak Identifier: 5645
Alert ID: 3126
July 31, 2023
Confirmed Case(s) - Official Quarantine

USDA

VSV Situation Report 7/28/2023

On July 27, the National Veterinary Services Laboratories in Ames, Iowa, confirmed vesicular stomatitis New Jersey virus (VSNJV) on an equine premises in White Pine County, Nevada. All four horses on the premises have met the confirmed VSV index case definition with compatible clinical signs (oral lesions) and either positive complement fixation test (CFT) on serum samples (2 horses) or VSNJV detection by real-time RT-PCR from oral lesion swabs (2 horses). There are no other livestock on the premises, which is a grazing pasture, and oral lesions in the horses were first noticed on July 23rd.  There have been no movements on or off the premises in the past 2 months. This is the 2023 VSV index case for Nevada. 

Additionally, since the last situation report (7/25/2023), there have been 15 new VSV-affected equine premises identified (4 confirmed positive, 11 suspect) in California.  All confirmed cases have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows:  

California

  • Los Angeles County – 1 new suspect equine premises
  • San Luis Obispo County – 1 new confirmed positive and 1 new suspect equine premises
  • Santa Barbara County – 3 new confirmed positive equine premises
  • Ventura County – 9 new suspect equine premises 
  • Since the last situation report (7/25/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 4 premises in Riverside County, 2 premises in San Bernardino County, and 5 premises in San Diego County. 

Texas

  • No new confirmed positive premises have been identified.

Since the start of the outbreak (5/17/2023), 152 VSV-affected premises have been identified (53 confirmed positive, 99 suspect) in 3 states, California, Nevada, and Texas.  One hundred forty-nine (149) 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 150 affected premises (51 confirmed positive, 99 suspect) in 8 counties (Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, and Ventura Counties).  Texas identified 1 affected premises (1 confirmed positive) in 1 county (Maverick County, Texas).  Nevada identified 1 affected premises (1 confirmed positive) in 1 county (White Pine County, Nevada).  

Of the 152 total VSV-affected premises, 93 premises have completed the quarantine period with no new clinical cases and have been released from quarantine.  Fifty-nine (59) premises remain quarantined.  

Additional information and maps of the affected area are contained in attached situation report which 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: 3115, 3111, 3099, 3090, 3085, 3071, 3066, 3060

White Pine County, NV
Outbreak Identifier: 5645
Alert ID: 3126
July 31, 2023
Confirmed Case(s) - Official Quarantine

USDA

VSV Situation Report 7/28/2023

On July 27, the National Veterinary Services Laboratories in Ames, Iowa, confirmed vesicular stomatitis New Jersey virus (VSNJV) on an equine premises in White Pine County, Nevada. All four horses on the premises have met the confirmed VSV index case definition with compatible clinical signs (oral lesions) and either positive complement fixation test (CFT) on serum samples (2 horses) or VSNJV detection by real-time RT-PCR from oral lesion swabs (2 horses). There are no other livestock on the premises, which is a grazing pasture, and oral lesions in the horses were first noticed on July 23rd.  There have been no movements on or off the premises in the past 2 months. This is the 2023 VSV index case for Nevada. 

Additionally, since the last situation report (7/25/2023), there have been 15 new VSV-affected equine premises identified (4 confirmed positive, 11 suspect) in California.  All confirmed cases have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows:  

California

  • Los Angeles County – 1 new suspect equine premises
  • San Luis Obispo County – 1 new confirmed positive and 1 new suspect equine premises
  • Santa Barbara County – 3 new confirmed positive equine premises
  • Ventura County – 9 new suspect equine premises 
  • Since the last situation report (7/25/2023), the following previously confirmed positive or suspect premises have been released from quarantine: 4 premises in Riverside County, 2 premises in San Bernardino County, and 5 premises in San Diego County. 

Texas

  • No new confirmed positive premises have been identified.

Since the start of the outbreak (5/17/2023), 152 VSV-affected premises have been identified (53 confirmed positive, 99 suspect) in 3 states, California, Nevada, and Texas.  One hundred forty-nine (149) 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 150 affected premises (51 confirmed positive, 99 suspect) in 8 counties (Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, and Ventura Counties).  Texas identified 1 affected premises (1 confirmed positive) in 1 county (Maverick County, Texas).  Nevada identified 1 affected premises (1 confirmed positive) in 1 county (White Pine County, Nevada).  

Of the 152 total VSV-affected premises, 93 premises have completed the quarantine period with no new clinical cases and have been released from quarantine.  Fifty-nine (59) premises remain quarantined.  

Additional information and maps of the affected area are contained in attached situation report which 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: 3115, 3111, 3099, 3090, 3085, 3071, 3066, 3060