In horses the mouth lesions were the most common. At first vesicles would develop and break, leaving a raw ulcer which was very sore. Some horses had only a few sores and some had almost the entire lip and tongue involved. Vesicular stomatitis is caused by a virus and the symptoms are similar to hoof and mouth disease, which was eradicated from the United States early in the century by the federal government. There is no treatment except to use antinflammatory medication to relieve pain and try to keep the horse eating and support them through the initial and most painful few days of the disease.
Mose cases occur in the summer or fall.
Flies are thought to be involved in the transmission, although some cases have occured in the winter. According the the literature, vesicular stomatitis is sporadic and not epidemic, but there have been epidemics two years in Western Colorado since I have been practicing here. Most years we see a few isolated cases in the fall. A small percentage of cases will have foot lesions. The coronet can be inflammed severly enough that as the hoof grows, the wall separates from the sensitive tissue around the coffin bone and the entire hoof and sole will come off.