Vesicular stomatitis virus can cause blisters and sores in the mouth and on the tongue, muzzle, teats, or hooves of horses, cattle, swine, sheep, goats, llamas and a number of other animals. | Photo: Courtesy Dr. Josie Traub-Dargatz

Horses in three states—Colorado, New Mexico, and Texas—have tested positive for vesicular stomatitis (VS), according to a July 8 report from the USDA Animal and Plant Health Inspection Service (APHIS).

The first cases of the year in the U.S. were diagnosed June 21 in horses residing in Kinney County, Texas. Since then, horses on three premises in Tom Green County and one premises each in Coleman and Kerr counties, all in Texas, have tested positive for VS, as well, the APHIS report said.

New Mexico’s first case was confirmed June 26 in Sandoval County. Cases have since been diagnosed in horses in Los Alamos and Valencia counties in that state, as