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Vesicular Stomatitus…what?

by Carol Stevens

HUERFANO-  The virus is called Vesicular stomatitis (ves-ICK-ular st-OO-ma-TIE-tis) or VS and has been found recently in horses in Texas and New Mexico. VS will primarily affect cattle, horses, swine, donkeys, llamas and alpacas, monkeys, raccoons, deer, bobcats and humans.  Sheep and goats are resistant.

    Brandon J. Freitas, the Extension Coordinator of Veterinary Medicine at Washington State University, states, “If livestock is found to be salivating excessively … or your horse goes lame, not eating, and when you get closer, you notice that the animal has blisters in its mouth, call your private veterinarian immediately or the Department of Agriculture.”  VS is painful, but the sores usually heal in two weeks to a month.  The animal should be isolated and tests done to confirm VS.

    The virus looks like Foot and Mouth Disease (FMD), but FMD does not affect horses, and FMD has not been detected in the United States since 1929.  The symptoms of VS in animals  are blisters, excessive salivation, erosions in the mouth, or crusty sores around an animal’s muzzle, teats or hooves.

    If humans become infected, VS causes a flu-like illness with fever, muscle aches, headache and weakness.  Humans rarely get oral blisters.  Recovery usually occurs in four to seven days.

    Transmission to livestock is from bites of the sandfly and blackfly or by direct contact with an infected animal.  Infected animals should be quarantined for about 30 days after lesions are healed.   VS rarely will result in death, however infected animals lose condition because they aren’t eating and drinking adequately.

    The best prevention strategies for VS are as follows:  controlling biting flies, keeping animals under a roof at night, using fly traps, cleaning stalls regularly, feeding/watering stock from their own individual buckets, disinfecting borrowed equipment/tools, and not visiting quarantined ranches.  To prevent the disease spreading to humans, use gloves and a mask when handling animals suspected of having VS.  For more information on this disease, visit U.S. Department of Agriculture at or