Vesicular stomatitis is a viral disease that primarily affects cattle, horses, and swine. The virus that causes vesicular stomatitis has a wide host range. This disease also occasionally affects sheep and goats. Many species of wild animals, including deer, bobcats, goats, raccoons, and monkeys, have been found to be susceptible hosts. Humans can also become infected with vesicular stomatitis when handling affected animals.

Vesicular stomatitis is most likely to occur during warm months in the Southwest, particularly along riverways and in valleys. The Southwestern United States experienced a vesicular stomatitis outbreak from May 1998 through January 1999. It is essential that veterinarians and livestock owners be on the alert for animals displaying clinical signs characteristic of the disease.

In affected livestock, vesicular stomatitis causes blisterlike 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 or 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.