Kansas State University

MANHATTAN — A Kansas State University veterinarian is cautioning residents of Kansas and surrounding states about a highly contagious viral disease that affects horses and livestock — and can sometimes affect humans.

At least 170 cases of vesicular stomatitis have been confirmed in Colorado and Texas, according to the U.S. Department of Agriculture's Animal Plant and Health Inspection Service. Outbreaks of this disease usually occur in late summer and early fall in more arid regions. Although two states are currently affected, Beth Davis, professor and section head of equine medicine and surgery at Kansas State University's Veterinary Health Center, says all animal owners need to be cautious when traveling with their animals.

"It's an interesting disease because it does have pretty significant clinical signs," Davis said. "Most commonly, it causes painful oral blisters in horses that can affect the mouth, muzzle and tongue. Additional signs may include lesions on the udder and/or around the top of the hoof where it meets the hairline. Vesicular stomatitis also can affect mules, donkeys, cattle, bison, swine, sheep, goats, llamas and alpacas."

If livestock owners suspect they are dealing with vesicular stomatitis, they should contact their veterinarian immediately because it is a reportable disease, Davis said.

"If you're dealing with a suspected case, communicate with your local veterinarian," Davis said. "Your veterinarian will communicate with state health officials and determine the best course of action."

Veterinarians and livestock owners work with state health officials to determine testing and quarantine protocols, which help identify animals infected and avoid their transport until viral shedding has ceased. When effective, the protocols will limit the spread of disease.

"It is quite contagious," Davis said. "The most common form of transmission is through insects, specifically biting flies. It also can be spread from one animal to another through direct contact and sharing of stable supplies."

Vesicular stomatitis is also potentially zoonotic, which means it can spread to humans, although it is rare. The elderly or immunocompromised are at higher risk of being infected. The virus causes mild flu-like symptoms in people and is generally resolved in about 10 days.

No vaccine is currently commercially available for vesicular stomatitis. Although the virus is very contagious, it is rarely fatal, Davis said. Animals that contract the disease often fully recover with supportive care like rest, fluids and soft food. Complete recovery may take three to four weeks. During that time, the animal is still contagious, which is why quarantine must be implemented on positive premises.

Davis also recommends that if you are traveling with horses or other livestock, check with the state's department of agriculture to ensure there are no travel restrictions.