media release

Colorado Department of Agriculture




August 2, 2012

Contact:     Christi Lightcap, (303) 239-4190,


Vesicular Stomatitis Diagnosed in Colorado

VS-Specific Travel Requirement Remains in Effect


LAKEWOOD, Colo. – A Las Animas County premises is under quarantine after a horse tested positive for vesicular stomatitis (VS); the horse had not recently traveled and is believed to have been infected by insects.  The Colorado Department of Agriculture recommends tips and guidelines for the horse and livestock industries.


“While this is the first case diagnosed in Colorado in 2012, there have been several cases identified in the Rio Grande River valley of New Mexico,” said State Veterinarian, Dr. Keith Roehr. “This Colorado case represents a northern movement of the virus that has been typical in past years.”


VS is a Foreign Animal Disease that occurs sporadically in certain areas of the western United States.   The last confirmed case of VS in Colorado was diagnosed in 2006. 


Travel Requirement

The Colorado Department of Agriculture’s State Veterinarian’s Office has issued a travel requirement for horses, mules, cattle, bison, sheep, goats, swine, and camelids entering the state from states with confirmed cases of VS.


This requirement states that health certificates should include the following statement from the issuing veterinarian, “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."


“The purpose of this requirement is to ensure that veterinarians issuing health certificates are aware of the spread of Vesicular Stomatitis and are vigilant in looking for signs of the virus.  VS can be painful for the animals and costly to their owners,” said Roehr. “While this virus does not typically cause death, the animal can suffer from painful sores so it is important to monitor herds for symptoms.”


Important Points for Veterinarians


Tips for Livestock Owners


Vesicular Stomatitis Guidelines for Shows and Fairs

The Colorado State Veterinarian’s Office is recommending that livestock events exercise extra precaution measures to minimize the transmission of Vesicular Stomatitis.  The following strategies should be implemented:

  1. Participants, regardless of origin should, when possible, arrive at the event with a Certificate of Veterinary Inspection that was issued within 48 hours of departure for the event.
  2. The Certificate of Veterinary Inspection should 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."
  3. Out-of-state participants should check with their state’s animal health officials to determine the requirements for their livestock’s return to that state.
  4. All livestock that arrive at an event without a Certificate of Veterinary Inspection issued within 48 hours of arrival should receive an oral examination for VS lesions upon arrival at the event. 
    1. A qualified, licensed and accredited veterinarian should be available to oversee the inspection process. 
    2. Any livestock that exhibit clinical signs of VS shall be immediately removed from the event and reported to a Colorado animal health official 303-239-4161.
    3. Colorado livestock will be returned to their premises and quarantined. 
    4. Out-of-state livestock should be taken to a predetermined isolation facility where they would be held until an appropriate quarantine site can be identified.
  5. During the event common water and feed sources should be minimized and insect repellent applied daily, with particular attention to the animals ears.


Vesicular Stomatitis Transmission

Most cases are spread by insect vectors particularly along river valleys.  Biting flies are known to be capable of transmitting VS.  Sand flies (Lutzomyia spp.) and black flies (Simulium spp.) have been identified as important insects in the transmission of VS.


Vesicular Stomatitis Signs

(Note:  a photo of the Las Animas County horse is available by emailing  The photo highlights the painful clinical signs of VS.)

VS susceptible species include horses, cattle, sheep, pigs, deer and other species of animals. The clinical signs of the disease include vesicles, 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.


As the disease progresses, the ruptured vesicles erode to produce areas where dead tissue becomes separated from the surrounding wound near the mouth or hoof.  Animals with oral lesions may refuse to eat or drink due to discomfort which results in weight loss.  Coronary band lesions can result in lameness in one or more feet.  In severe situations, the hoof may slough or hoof growth may be permanently impacted.


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.


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 diagnosed with VS are isolated until they are free from clinical signs of disease and no longer present a risk to other livestock.  There are no US Department of Agriculture approved vaccines for VS.


For additional information, contact the Colorado State Veterinarian’s office at 303-239-4161 or visit   


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