The virus causes vesicles (blisters) that form primarily on the lips and tongue. | Photo: Courtesy Dr. Josie Traub-Dargatz

Of particular concern is this summer’s outbreak of vesicular stomatitis virus (VSV) among Colorado horses. Infection has forced the quarantine of 206 properties, where horses and some cattle have tested positive for the disease, the Colorado State Veterinarian’s Office reported on Monday, and. That number is expected to climb.

To help horse owners, Paul Morley, DVM, PhD, Dipl. ACVIM, a CSU veterinarian and director of infection control for the university’s James L. Voss Veterinary Teaching Hospital, answers common questions about preventing infection.

Q: What are the symptoms of VSV?

A: The main symptoms of vesicular stomatitis virus are blisters, sores, and sloughing of skin in the mouth, on the tongue, on the muzzle and ears, and above the hooves. Lameness and weight loss may also occur. Horses have been hit hardest during this summer’s outbreak in Colorado, although several cows have been confirmed as infected. Weld, Boulder, and Larimer counties in northern Colorado have the highest number of confirmed cases. VSV can threaten a number of other livestock species, including sheep, goats and pigs