Disease Alerts

Comments: Since the last VSV situation report (7/7/2026), 2 new confirmed positive equine premises have been identified, 1 in Archuleta County and 1 in La Plata County, Colorado (both new affected counties). Additionally, 1 new VSV-presumptive positive equine premises has been quarantined in Valencia County, New Mexico. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. 

Updates are as follows: Colorado • Archuleta County (New Affected County) – 1 new confirmed positive equine premises • La Plata County (New Affected County) – 1 new confirmed positive equine premises.

Since the last situation report (7/7/2026), 1 previously VSV-affected premises in Montrose County has been released from quarantine New Mexico • Valencia County – 1 new presumptive positive equine premises • Since the last situation report (7/7/2026), 1 previously VSV-affected premises in Rio Arriba County has been released from quarantine. Since the start of the outbreak, 35 VSV-affected premises have been identified (27 confirmed positive, 8 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 35 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 4 premises located in 4 Colorado counties (Archuleta, La Plata, Montezuma, and Montrose Counties), and 16 premises located in 4 New Mexico counties (Rio Arriba, Sandoval, Santa Fe, and Valencia Counties). Since the start of the outbreak, 35 VSV-affected premises have been identified (27 confirmed positive, 8 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 35 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 4 premises located in 4 Colorado counties (Archuleta, La Plata, Montezuma, and Montrose Counties), and 16 premises located in 4 New Mexico counties (Rio Arriba, Sandoval, Santa Fe, and Valencia Counties).;

For more information, go to https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis

Comments: Since the last VSV situation report (7/1/2026), two (2) new VSV-presumptive positive equine premises have been quarantined in Rio Arriba County, New Mexico. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Colorado • A VSV-affected equine premises remains quarantined in Montrose County, Colorado- New Mexico • Rio Arriba County – 2 new presumptive positive equine premises have been quarantined • Since the last situation report (7/1/2026), 3 previously VSV-affected premises have been released from quarantine in Rio Arriba (1) and Valencia (2) counties. Since the start of the outbreak, 32 VSV-affected premises have been identified (25 confirmed positive, 7 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 32 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 2 premises located in 2 Colorado counties (Montezuma and Montrose Counties), and 15 premises located in 4 New Mexico counties (Rio Arriba, Sandoval, Santa Fe, and Valencia Counties).;

Comments: Since the last VSV situation report (6/30/2026), one (1) new VSV-affected equine premises has been confirmed positive in Montrose County, Colorado (New Affected County). All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Colorado • Montrose County (New Affected County) – 1 new confirmed positive equine premises has been quarantined New Mexico • VSV-affected equine premises remain quarantined in Rio Arriba and Valencia Counties. Since the start of the outbreak, 30 VSV-affected premises have been identified (25 confirmed positive, 5 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 30 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 2 premises located in 2 Colorado counties (Montezuma and Montrose Counties), and 13 premises located in 4 New Mexico counties (Rio Arriba, Sandoval, Santa Fe, and Valencia Counties).;

For more information, go to https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis

Comments: Since the last VSV situation report (6/26/2026), one (1) new VSV-affected equine premises has been confirmed positive in Rio Arriba County, New Mexico (New Affected County). All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • The last VSV-quarantined premises in Arizona was released on 4/20/2026 and no new cases have been identified to date. Colorado • The last VSV-quarantined premises in Colorado was released on 5/26/2026 and no new cases have been identified to date. New Mexico • Rio Arriba County (New Affected County) – 1 new confirmed positive equine premises • Since the last situation report (6/26/2026), 5 previously VSV-affected equine premises have been released from quarantine in Santa Fe County (1) and Valencia County (4). Since the start of the outbreak, 29 VSV-affected premises have been identified (24 confirmed positive, 5 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 29 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 1 premises located in 1 Colorado county (Montezuma County), and 13 premises located in 4 New Mexico counties (Rio Arriba, Sandoval, Santa Fe, and Valencia Counties).;

For more information, go to https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis

Comments: Since the last VSV situation report (6/12/2026), five (5) new VSV-affected equine premises (1 confirmed positive, 4 presumptive positive) have been quarantined in New Mexico. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • The last VSV-quarantined premises in Arizona was released on 4/20/2026 and no new cases have been identified to date. Colorado • The last VSV-quarantined premises in Colorado was released on 5/26/2026 and no new cases have been identified to date. New Mexico • Santa Fe County – 1 new presumptive positive equine premises • Valencia County – 1 new confirmed positive equine premises and 3 new presumptive positive equine premises • Since the last situation report (6/12/2026), 3 previously VSV-affected equine premises have been released from quarantine in Santa Fe County (1) and Valencia County (2). Since the start of the outbreak, 28 VSV-affected premises have been identified (23 confirmed positive, 5 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 28 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 1 premises located in 1 Colorado county (Montezuma County), and 12 premises located in 3 New Mexico counties (Sandoval, Santa Fe, and Valencia Counties).;

For more information, go to https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis

Comments: Since the last VSV situation report (6/10/2026), four (4) new VSV-affected equine premises have been confirmed positive in Valencia County, New Mexico (New Affected County). All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • The last VSV-quarantined premises in Arizona was released on 4/20/2026 and no new cases have been identified to date. Colorado • No new VSV-affected premises have been identified. New Mexico • Valencia County (New Affected County) – 4 new confirmed VSV-positive equine premises have been identified. Since the start of the outbreak, 23 VSV-affected premises have been identified (22 confirmed positive, 1 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 23 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 1 premises located in 1 Colorado county (Montezuma County), and 7 premises located in 3 New Mexico counties (Sandoval, Santa Fe, and Valencia Counties). There were other susceptible species also present on VSV premises in Arizona (cattle on 5 premises, goats on 2 premises) in Cochise, Gila, Maricopa, Santa Cruz, and Yavapai Counties, and in New Mexico (goats on 2 premises) in Sandoval and Valencia Counties, but they were not clinically affected.;

For more information, go to https://www.aphis.usda.gov/sites/default/files/vsv-sitrep-6-12-26.pdf

Comments: Since the last VSV situation report (5/26/2026), one new VSV-affected equine premises has been confirmed positive in Santa Fe County, New Mexico (New Affected County). All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • The last VSV-quarantined premises in Arizona was released on 4/20/2026 and no new cases have been identified to date. Colorado • No new VSV-affected premises have been identified. Since the last situation report (5/26/2026), 1 previously VSV-affected premises was released from quarantine in Montezuma County, New Mexico • Santa Fe County (New Affected County) – 1 new confirmed VSV-positive equine premises has been identified. • Since the last situation report (5/26/2026), 2 previously VSV-affected equine premises have been released from quarantine in Sandoval County (1 confirmed positive and 1 presumptive positive premises). Since the start of the outbreak, 19 VSV-affected premises have been identified (18 confirmed positive, 1 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 19 premises have had only equine species clinically affected with 15 premises located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 1 premises located in 1 Colorado county (Montezuma County), and 3 premises located in 2 New Mexico counties (Sandoval and Santa Fe Counties). There were other susceptible species also present on VSV premises in Arizona (cattle on 5 premises, goats on 2 premises) in Cochise, Gila, Maricopa, Santa Cruz, and Yavapai Counties, but they were not clinically affected.;

For more information, go to https://www.aphis.usda.gov/sites/default/files/vsv-sitrep-6-10-26.pdf

Comments: On May 22, 2026, the National Veterinary Services Laboratories (NVSL) in Ames, Iowa, confirmed vesicular stomatitis New Jersey virus (VSNJV) on an equine premises in Sandoval County, New Mexico. One (1) horse out of 3 horses on the premises had compatible clinical signs and was VSNJV-positive by both polymerase chain reaction (PCR) on swabs of the lesions and competitive enzyme-linked immunosorbent assay (cELISA) on serology. This is the index case of VSV for New Mexico in 2026. Additionally, since the index case was confirmed, a second equine premises in Sandoval County, New Mexico, has horses exhibiting compatible clinical signs of VSV and has been categorized as presumptive positive without testing. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Since the start of the outbreak, 18 VSV-affected premises have been identified (17 confirmed positive, 1 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 18 premises have had only equine species clinically affected in six Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 1 premises in 1 Colorado county (Montezuma County), and 2 premises in 1 New Mexico county (Sandoval County).;

For more information, go to https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis

Comments: Since the start of the outbreak,16 VSV-affected premises have been identified (16 confirmed positive, 0 presumptive positive) in 2 states, Arizona and Colorado. All 16 premises have had only equine species clinically affected in six Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties) and 1 premises in 1 Colorado county (Montezuma County). There were other susceptible species also present on VSV premises in Arizona (cattle on 5 premises, goats on 2 premises) in Cochise, Gila, Maricopa, Santa Cruz, and Yavapai Counties, but they were not clinically affected. For more information go to: https://www.aphis.usda.gov/livestock-poultry-disease/cattle/vesicular-stomatitis;