Vesicular Stomatitis (VS)

Vesicular Stomatitis Guidelines for Livestock Shows, Fairs, Exhibitions, and Events

The primary spread of VS is thought to occur through insects that migrate along river valleys. Colorado livestock owners are warned to take added precautions due to the proximity of the virus.

Veterinarians and livestock owners who suspect an animal may have VS or any other vesicular disease should immediately contact State or Federal animal health authorities. Livestock with symptoms of VS are isolated until they are cleared through the US Department of Agriculture diagnostic laboratory testing. There are no USDA approved vaccines for VS.

While rare, human cases of VS can occur, usually among those who handle infected animals. VS in humans can cause flu-like symptoms and only rarely includes lesions or blisters.

Vesicular Stomatitis (VS) Signs and Transmission

VS susceptible species include horses, cattle, sheep, pigs, deer, and other species of animals. The clinical signs of the disease include blisters in the mouth and above the hoof, erosions, and sloughing of the skin on the muzzle, tongue, teats, and above the hooves of susceptible livestock. Vesicles are usually only seen early in the course of the disease.

Tips for Livestock Owners

  • Strict fly control is an important factor to inhibit the transmission of the disease.
  • Avoid transferring feeding equipment, cleaning tools or health care equipment from other herds.
  • Colorado livestock owners should contact the state of destination when moving livestock interstate to ensure that all entry requirements are met. A list of contact information for all state veterinarians’ offices is available at:
  • Colorado fairs, livestock exhibitions, and rodeos may institute new entry requirements based on the extent and severity of the current VS outbreak. Be sure to stay informed of any new livestock event requirements.

The Colorado State Veterinarian’s Office is recommending that Colorado livestock shows, fairs, exhibitions, and events exercise extra precautionary measures to minimize the transmission of VS.  The following strategies are recommended:

  • Participants from New Mexico, when possible, should arrive at the event with a health certificate that was issued within 48 hours of departure for the event.
  • For New Mexico participants, the health certificate must contain a statement from the issuing veterinarian that states; “I have examined the animal(s) represented on this Certificate of Veterinary Inspection (CVI) and have found no signs of vesicular stomatitis and they have not originated from a premises under quarantine for vesicular stomatitis.”
  • New Mexico livestock participants that arrive without a CVI issued within 48 hours should receive an oral inspection for VS lesions upon arrival at the event.  A qualified, licensed, and accredited veterinarian should oversee and direct the veterinary inspections. If any animal is suspected of VS the animals should be immediately removed from the event and reported to the State Veterinarian’s Office at 303-239-4161.  Affected Colorado livestock will be returned to their premises and quarantined.  Out-of-state livestock will be taken to a predetermined isolation facility where they will be held until an appropriate quarantine site can be identified.
  • During the event, important VS disease prevention procedures include minimizing the sharing of water and feed/equipment, applying insect repellent daily (especially to the animals ears), and closely observing animals for signs of vesicular stomatitis.

For additional information, contact the Colorado State Veterinarian’s office at 303-239-4161 or click here for information on the CDA’s website.

To view the current location of cases and other important updates and information, visit

Vesicular Stomatitis Fact Sheet (PDF)