Vesicular Stomatitis Detected in New Mexico

On April 27, the USDA's National Veterinary Services Laboratories (NVSL) in Ames, Iowa, confirmed the finding of vesicular stomatitis virus (VSV) in horses at one premises in Grant County, N.M. This is the first confirmed case of vesicular stomatitis in the United States in 2005.

Vesicular stomatitis is a viral disease that primarily affects horses, cattle, and swine. Vesicular stomatitis virus 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. The 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 affected premises has six horses and approximately 110 head of cattle.

Only two horses are known to have clinical signs and none of the cattle are showing clinical signs. All animals susceptible to vesicular stomatitis are being held on the premises.

Laboratory results showed that both ill horses were positive on the complement fixation (CF) test and virus isolation was achieved from one horse. The isolate is the New Jersey strain of VSV.

The last case of VS in the United States was confirmed in the State of Colorado in December 2004.

The Animal and Plant Health Inspection Service's Veterinary Services and the New Mexico Livestock Board will continue to monitor the situation and conduct response activities in an effort to minimize trade restrictions.

For additional information on vesicular stomatitis, visit:

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More