Vesicular Stomatitis Now Found in Texas

By Glenn Selk, OSU Extension

'Texas, on Friday, 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 vesicular stomatitis virus (VSV). 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 now, Texas.

Vesicular stomatitis is a viral disease which primarily affects horses, cattle, and swine. The agent that causes vesicular stomatitis, VSV, has a wide host range and can occasionally infect sheep and goats. In affected livestock, VSV causes blister-like lesions to form in the mouth and on the dental pad, tongue, lips, nostrils, hooves, and teats. These blisters swell and break, leaving raw tissue that is so painful that infected animals generally refuse to eat and drink and show signs of lameness. Severe weight loss usually follows, and in dairy cows a severe drop in milk production commonly occurs. Affected dairy cattle can appear to be normal and will continue to eat about half of their feed intake.

The clinical signs of VS mirror those of the dreaded foreign foot-and-mouth (FMD) disease. Horses are susceptible to VS, but not FMD; however, both diseases can affect cattle, sheep, goats, swine, deer and a number of other species. When sores or blisters are seen in FMD-susceptible animals, veterinarians must immediately rule out an introduction of foot-and-mouth disease (FMD). When horses have lesions, a VS test rules out other possible causes for blisters and sores, including toxic plants, chemicals or poison.

The State of Oklahoma will require a statement on the Certificates of Veterinary Inspection on all animals except poultry coming from New Mexico, Arizona, and TEXAS stating that: “the animal (s) listed on the CVI, do not originate from an area under quarantine for Vesicular Stomatitis and that the animal (s) do not have any visible vesicular lesions”.

Anyone that observes clinical signs such those previously described for vesicular stomatitis should report these situations to a local veterinarian and/or (if you reside in Oklahoma) to the Oklahoma Department of Agriculture, Food, and Forestry Animal Industry Division: phone 405-522-6131.

More information about “vesicular stomatitis” can be found by consulting the following pdf file on the APHIS website.'