Disease Alerts

Comments: Since the last situation report (3/4/2026), there have been two (2) new confirmed VSV-positive equine premises identified in Arizona (Yavapai County). All confirmed cases in the 2025-26 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • Yavapai County – 2 new equine premises confirmed VSV-positive on 4/6/2026 • Since the last situation report (3/4/2026), four (4) previously VSV-affected premises have been released from quarantine in Gila (1), Maricopa (1), and Yavapai (2) Counties. Classification of Cases Premises that have diagnostic laboratory confirmation of VSV are categorized as confirmed positive premises. Once a county is confirmed as VSV-positive, new equine premises presenting with clinical signs of VSV in that county are not required to be tested for confirmation of the disease, but the premises will be quarantined and classified as a presumptive positive premises. Premises may also be classified as presumptive positive if clinical animals on the premises fail to meet confirmed case definition, but there is diagnostic laboratory evidence of recent VSV infection. For more info go to: https://www.aphis.usda.gov/sites/default/files/vsv-sitrep-4-7-26.pdf;