BROOMFIELD, Colo. – Agriculture officials in Colorado hope frost conditions in the state will mean a decline in cases of vesicular stomatitis. As of Nov. 4, 80 locations in 17 counties were placed under quarantine after cattle herds, horses and mules tested positive for the virus, the State Veterinarian’s Office of the Colorado Department of Agriculture reported.

“Now that most areas of the state have had a frost, the insect populations should be subsiding,” said State Veterinarian, Dr. Keith Roehr. “We hope this translates into rapidly decreasing case numbers as well. But, until we see those case numbers reduced, I encourage all livestock owners to be aware of their county status and take the proper precautions to prevent insect populations on their property.”

Vesicular stomatitis is a viral disease that mainly affects horses and cattle. However other livestock, such as sheep, goats and swine, also can be infected. The disease causes lesions in animals’ mouths and udders, but generally is not fatal and rarely affects humans. The disease typically is spread through biting insects and midges, and nose-to-nose contact between infected and non-infected animals.

In October, the Utah Dept. of Agriculture and Food reported the virus had spread to nine counties, while other cases previously were reported in Texas, New Mexico, Arizona, Wyoming and South Dakota.

The US Department of Agriculture changed the 2015 state response to VS by delisting the disease as foreign animal disease in horses. VS remains listed as a foreign animal disease for cattle and livestock, according to the CDA. The change means states have more flexibility to manage equine VS cases.

“The new protocols allow our office to release quarantines more quickly which ensures appropriate disease safeguards and promotes business continuity,” Roehr explained.

VS disease prevention measures include minimizing the sharing of water, feed and equipment; applying insect repellent daily (especially to the animal’s ears); and closely observing animals for signs of VS.

“While we cannot disclose the exact location of the infected livestock, it is not very contagious from animal to animal,” Roehr said. “The primary method of spread is through insect vectors, primarily biting flies. The key to remember is to take steps to reduce the fly populations near livestock.”