Vesicular Stomatitis In Horses

Last Updated on February 19, 2022 by Allison Price

Vesicular stamatitis (VS), a contagious disease, can affect horses, livestock, wildlife, and humans. Although the disease is not life-threatening, it can have a significant financial impact on horses. Vesicular Stomatitis can be reported. Your veterinarian will contact the state and federal animal health officials if there is any suspicion. Your state veterinarian will quarantine any affected ranch or farm once a confirmed case of vesicular Stomatitis has been confirmed. Horses and other vulnerable species will be kept away from that area for at least 14 days after the first case. This is done to reduce the risk of spreading the disease. Equestrian event organizers might also decide to cancel horse shows and rodeos in the area. International and interstate movement of horses could also be restricted.

Clinical Signs & Diagnose

Vesicular Stomatitis is a condition in which blister-like lesions develop on horses’ tongues, lips, mouth linings, noses, and lips. Sometimes, lesions may develop on the coronary band, udder, or sheath. If VS is suspected, it should be confirmed by testing blood for virus-specific antibodies. Swabs from the lesions can also be tested to confirm the presence of the virus. To rule out the possibility of lesions being caused by photosensitivity (sunburn), irritation feeds or weeds or toxicity from nonsteroidal anti-inflammatory drugs like phenylbutazone, testing is required.

VS should not to be confused with FMD, which is not a disease that affects horses and was eliminated from the U.S.A.A. in 1929. Incubation for vesicular Stomatitis, which is the time between exposure and the first symptoms appearing, can be as short as 2-8 days. Initial signs of fever include blisters on the gums, tongue, and coronary bands. Drooling, frothing at your mouth, and possibly a reluctance or refusal to eat are some of the symptoms. This happens after painful blisters have ruptured. It is possible for the tongue’s surface to slough. A dental problem can often be mistaken for excessive salivation. Colic in horses may also occur when they are not eating well. A secondary effect of mouth ulcers is weight loss. Horses with painful stomach problems may experience weight loss. Inflammation within the foot can cause lameness and laminitis if lesions develop around the coronary bands. The lesions around the coronary band can cause the hoof or hoof to slough in severe cases (but this is rare).

Although the disease usually resolves in two weeks, it can take up to two months for sores completely to heal. The live virus can be often isolated from lesions up to one week after they appear. The horse can remain infected for up to a week after the lesions appear. However, there is still the possibility of the disease spreading to other animals.

Stomatitis In Horses


Soft feeds can be helpful for horses suffering from vesicular Stomatitis. As supportive care, anti-inflammatory medication may be administered to reduce swelling and pain. Horses can continue to drink and eat as normal. Your veterinarian may recommend intravenous fluids to support your horse’s recovery if he becomes dehydrated due to insufficient water intake. Another concern is secondary bacterial infection in ulcerated areas. Treatment with antibiotics may also be necessary if there is swelling, pus, inflammation, or fever around the sores. Regularly flushing the mouth with an antiseptic solution, such as chlorhexidine, can reduce secondary bacterial contamination and speed up healing. The owner or veterinarian cannot do anything except wait for the healing process to take place and take the necessary precautions to reduce the spread of the disease among other horses.

Disease Transmission

It is not clear how vesicular Stomatitis is transmitted or why it occurs so rarely in the United States. It is only found in North, Central and South America. The disease is more common in warmer areas. It is thought that the virus’ life cycle is maintained by insects like midges and biting flies, which are seasonal. Midges, black flies, sandflies and sandflies are all known to transmit the virus. However, there may be other vectors. Horses can also be infected by saliva or liquid from ruptured blisters. Potential spread can be easily caused by physical contact between horses or animals or with equipment, housing, trailers and feed.


The following guidelines can be used to prevent the occurrences of VS:

* Healthier horses are more resistant to disease so ensure regular exercise, good nutrition, and routine vaccinations.

* Keep new horses isolated for at least 21-days before you introduce them to the stable or herd.

* Observe your horse closely. Any horse with signs of infection should be immediately isolated and contacted your veterinarian.

* Use an effective program to control insects. Make sure that stabling areas are dry and clean. Get rid of manure and remove any potential breeding areas (standing water, muddy places) for insects vectors.

* Use individual feeders, waterers, or equipment, rather than collective.

Regularly clean and disinfect waterers, feed bunks, horse trailers, and other equipment.

* Make sure your farrier and any other equine professionals that come in direct contact with your horses exercise due care to prevent spreading the disease to other horses or facilities.

* If VS is suspected on farms, keep lesions from spreading to other animals and treat ill animals first. To prevent others from being exposed, handlers must wash and change clothes.

* All persons who handle infected horses must use biosafety procedures, such as wearing latex gloves and washing their hands after handling animals with lesions.

* Sponsoring an event during an outbreak requires a current health certificate for each horse. Also, consider having a veterinarian inspect all horses at check in. If a suspected case is found at the venue, work with your veterinarian to develop an isolation plan and emergency response protocols.

Vesicular Stomatitis In Humans

Infected horses can cause vesicular stamatitis in humans. To avoid contracting the virus, it is essential to use biosafety precautions when handling infected horses. Wearing latex gloves and avoiding contact with horse saliva or blister fluids are good precautions. You should take extra care to prevent infection from reaching your mouth, eyes, and open wounds. Horses can sneeze and snort infectious secretions. To avoid getting sprayed in your face, you should keep your horse to one side.

Human vesicular stomatitis can cause severe flu-like symptoms, such as headaches, fever, and muscle aches. Rarely, people get blisters in the mouth. If you have influenza-like symptoms following VS-infected horses, please contact your doctor immediately.

Vaccines And Disinfectants

Although vaccines have been tested experimentally to combat vesicular stamatitis, none of them are approved for horses. It is still controversial whether vaccination can prevent or reduce the severity of an outbreak. Although the protection period is short, once animals have been vaccinated they will be able to test positive for a long time. This can lead to travel restrictions.

The virus responsible for vesicular stamatitis can be destroyed by heat and sunlight. Other disinfectants that are effective include chlorine bleach (0.65%), Wescodyne (4 %) and Septisol (1.50), Roccal (1.200), Cresylic Acids (1 %).

Working with Your Veterinarian

Allison Price
Allison Price

I’m Allison, born and raised in San Diego California, the earliest memory I have with horses was at my grandfather’s farm. I used to sit at the stable as a kid and hang out with my Papa while he was training the horses. When I was invited to watch a horse riding competition, I got so fascinated with riding!