Disease Alerts

Comments: A new USDA Vesicular Stomatitis situation report, including quarantine release information, is available here https://www.aphis.usda.gov/sites/default/files/vsv-sitrep-9-3-26.pdf

Comments: Since the last VSV situation report (8/13/2026), three presumptive positive equine premises in La Plata County and Montezuma County, Colorado, have been quarantined. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. 

Updates are as follows: • La Plata County – 1 new presumptive positive equine premises • Montezuma County – 2 new presumptive positive equine premises. Since the last situation report (8/13/2026), 1 previously VSV-affected equine premises has been released from quarantine in La Plata County. 

Since the start of the outbreak, 45 VSV-affected premises have been identified (31 confirmed positive, 14 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. Forty-three (43) premises have had only equine species clinically affected Of the 45 affected premises, 15 were located in 6 Arizona counties (Cochise, Gila, Maricopa, Pinal, Santa Cruz, and Yavapai Counties), 14 premises were located in 5 Colorado counties (Archuleta, Delta, La Plata, Montezuma, and Montrose Counties), and 16 premises were 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 (8/10/2026), 1 new confirmed VSV-positive equine premises has been identified in La Plata County, Colorado. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. 

Updates are as follows: Colorado • La Plata County – 1 new confirmed positive equine premises • Since the last situation report (8/10/2026), 2 previously VSV-affected equine premises have been released from quarantine in Montrose County. 

New Mexico • No new VSV-affected premises have been quarantined. 

Since the start of the outbreak, 40 VSV-affected premises have been identified (30 confirmed positive, 10 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 40 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), 9 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 (7/24/2026), 2 new confirmed VSV-positive equine premises have been identified in Montrose County, Colorado. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. 

Updates are as follows: Colorado • Montrose County – 2 new confirmed positive equine premises • Since the last situation report (7/24/2026), 4 previously VSV-affected equine premises have been released from quarantine in Archuleta County (2), La Plata County (1), and Montezuma County (1). 

New Mexico • Since the last situation report (7/24/2026), 2 previously VSV-affected equine premises have been released from quarantine in Rio Arriba and Valencia Counties. 

Since the start of the outbreak, 39 VSV-affected premises have been identified (29 confirmed positive, 10 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 39 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), 8 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/sites/default/files/vsv-sitrep-8-10-26.pdf

Comments: Since the last VSV situation report (7/20/2026), 2 new presumptive positive equine premises have been quarantined, 1 in Archuleta County and 1 in Montezuma County, Colorado. All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. 

Updates are as follows: Colorado • Archuleta County – 1 new presumptive positive equine premises • Montezuma County – 1 new presumptive positive equine premises New Mexico • VSV-affected premises remain quarantined in Rio Arriba County and Valencia County, New Mexico 

Since the start of the outbreak, 37 VSV-affected premises have been identified (27 confirmed positive, 10 presumptive positive) in 3 states, Arizona, Colorado, and New Mexico. All 37 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), 6 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 (7/7/2026), 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