So far vesicular stomatitis has been limited to the western hemisphere. It primarily affects cattle, horses and swine. Vesicular stomatitis is zoonotic, meaning that humans are susceptible to the virus as well.
The disease typically occurs in the United States from late spring through early fall. Outbreaks of vesicular stomatitis generally occur at about 10-year intervals, although favorable climatic conditions can bring on more outbreaks. Previous outbreaks in horses occurred in 1982, 1983, and 1985, primarily in the West and Midwest United States.
How vesicular stomatitis spreads is not completely known. Insect vectors, mechanical transmission and movement of animals may play a role.
Once the disease is in a herd, it moves from animal to animal by contact and exposure to saliva. If humans are exposed to the virus, symptoms are flu-like, with fever, muscle and headaches.
Vesicular stomatitis has an incubation period of five - eight days, during which time the horse may have a moderated fever and be slightly depressed.
There is no specific treatment or vaccination for vesicular stomatitis. Treatment strategies may include mild antiseptic mouthwashes and good sanitation.
What does this mean to horse owners in this part of the U.S.?
To date, there have been no confirmed cases of vesicular stomatitis in the region.
However, if your horse demonstrates any of the clinical signs, contact your veterinarian immediately. When a definite diagnosis is made on a farm by blood tests, your veterinarian may recommend the following procedures:
- Isolate from healthy animals.
- Do not move horses from the premises fro at least 30 days after the last lesion has healed.
- Implement insect control programs on the farm.
- Use protective gloves (latex) and exercise proper precautionary measures when handling affected animals to avoid human exposure to this disease.
If your horse has mouth ulcers...
Don't assume vesicular stomatitis. Other causes of oral ulceration in horses include:
- Phenylbutazone toxicity.
- Oral foreign bodies (plant thorns, wood splinters, etc.)
- Chemical stomatitis.
- Periodontal disease.
- Blister beetle toxicosis.
Obviously, careful examination by a veterinarian is a must to identify and differentiate among these problems.
What is vesicular stomatitis?
Vesicular stomatitis (literally, blisters in the mouth) is a virus which
- causes excessive salivation and slow eating.
- Close examination of an infected mouth will reveal multiple small raised vesicles or ulcers generally on the upper surface of the tongue. If the condition is severe, the ulcers progress to erosions that affect the lips, cheeks and, occasionally, the coronary band.
- Vesicular stomatitis does not generally cause horses to die, but infected animals often stop eating and drinking. Severe weight loss usually follows.
- If there are no complications, such as secondary infections, the affected animals recover in about two weeks.
For more information, contact the USDA, APHIS, Veterinary
Services, Emergency Programs, Unite 41, 4700 River Road, Riverdale, MD
20737-1231. Phone: (302) 734-8073.