Disease Alerts

Comments: Since the last situation report (11/24/2025), there has been one (1) new confirmed positive equine premises identified in Arizona (Santa Cruz County - new affected county). All confirmed cases in the 2025 outbreak have been vesicular stomatitis New Jersey virus (VSNJV) serotype. Updates are as follows: Arizona • Cochise County – no new positive premises • Gila County – no new positive premises • Santa Cruz County (New Affected County) – 1 new confirmed positive equine premises. 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. United States Department of Agriculture Animal and Plant Health Inspection Service. Vesicular stomatitis virus circulates annually between livestock and insect vectors in southern Mexico and only occasionally results in incursion to the U.S. when climatic and ecological factors support movement of VSV-infected insect vectors northward.;