Texas on May 20 joined New Mexico and Arizona as states with confirmed cases of vesicular stomatitis (VS) this spring. Two Travis County horses were hauled home May 10 from a trail ride in Arizona, where they apparently were exposed to the VS virus. The virus can cause animals to develop blisters and sores in the mouth and on the tongue, muzzle, teats, and hooves. The year’s first VS cases were confirmed April 27 in two horses in southwest New Mexico. Since then, infection has been detected in 17 horses on 11 premises in New Mexico, Arizona, and Texas.

Bob Hillman, DVM, head of the Texas Animal Health Commission (TAHC) and Texas’ state veterinarian, urged horse owners to check with the state or country of destination before hauling livestock from Texas, since many states have imposed strict testing, permit, and inspection requirements for livestock originating from VS-affected areas. Phone numbers for other states’ animal health regulatory agencies can be obtained from the TAHC’s Austin headquarters at 800/550-8242. Staff at the USDA’s Austin office can be reached at 512/916-5565 for international shipping rules or restrictions.

To help prevent the spread of VS, an infected animal and the other livestock on a premises are quarantined until at least 30 days after the sores heal.

The clinical signs of VS mirror those of the foreign malady foot and mouth disease (FMD), so it is important to rule out FMD in livestock other than horses (horses aren’t infected by FMD). Tests are run at no charge to the animal owner, and the VS diagnosis in horses is confirmed at the National Veterinary Services Laboratory in Ames, Iowa.

Livestock owners and private veterinary practitioners are urged to report suspected cases of VS to their respective states’ livestock health regulatory agency. For more information, see www.TheHorse.com/ViewArticle.aspx?id=5796