Cases of vesicular stomatitis (VS) continue to be detected in Texas, New Mexico and Colorado, but the disease appears to be occurring at lower levels than in previous years’ outbreaks. As of July 22, nine premises in Texas and 11 in New Mexico are under quarantine, due to VS infection. In Colorado, 10 horses and three head of cattle are quarantined on premises in four counties. The viral infection, thought to be spread by sand flies or black flies, can cause horses, cattle and other livestock to develop blister-like lesions that can take several weeks to heal.