Protect Your Horse From Vesicular Stomatitis

Researchers investigated how you can best protect your horses from contracting the vesicular stomatitis virus. Here’s what they found.

No account yet? Register


Protect Your Horse From Vesicular Stomatitis
Vesicular stomatitis virus can cause blisters and sores in the mouth and on the tongue, muzzle, teats, or hooves of horses, cattle, swine, sheep, goats, llamas, and a number of other animals. | Photo: Courtesy Dr. Ashley Salinas
If you’re a horse enthusiast (well, of course you are!), you’ve no doubt noticed news articles confirming the resurgence of vesicular stomatitis (VS) outbreaks in the United States in recent years. In fact, 2019 saw the largest VS outbreak in the 40 years federal officials have tracked the disease, beating out the previous high set in 2015, said Angela Pelzel-McCluskey, DVM, equine epidemiologist for the USDA Animal and Plant Health Inspection Service (APHIS).

To help you protect your horses, we at are sharing measures recommended by experts in a recent Journal of Equine Veterinary Science review article.

Insect Control

Because biting insects are the most common source of vesicular stomatitis virus (VSV), the best way to prevent VS is to remove insects from the horse and his habitat. The researchers specify four spatial scales you can use to reduce risk:

1. Neighborhood:

  • Rotate pastures to avoid grazing during periods of water’s base flow just following peak runoff, which a hydrology study found correlated with past outbreaks.
  • Move horses to higher-elevation pastures (4,000 feet and above) during high-vector seasons.
  • Pesticides might be prohibited near drinking water sources; try propane-fueled insect traps that emit insect-attracting carbon dioxide, placed between insects’ breeding habitat and horses’ premises.

2. Premises:

  • Provide a run-in shed that horses can use to escape insects.
  • Remove manure regularly to reduce insect habitat.
  • Provide good drainage (slope, well-drained sand, and porous gravel) around water sources to minimize habitat for water- and mud-loving insects.
  • Keep vegetation short to minimize insects’ favored breeding and living areas.
  • Manage irrigation to minimize pooled water and mud in fields.

3. Shelter:

  • Keep animals indoors during insects’ active feeding periods (do some research to determine which insects are your area’s most common vectors and plan accordingly).
  • Install mesh nets (0.1825 mm2 pore size) or repellent-treated fabric on doors and windows or around stalls, or use as an outdoor net-shed.
  • Install downward-blowing fans to keep insects off horses.
  • Minimize bright insect-attracting lights at night, including light traps and bug zappers.

4. Animal:

  • Apply topical repellents and insecticides with the understanding that they aren’t equally effective on all insect species.
  • Use protective horsewear such as fly sheets, leg wraps, fly masks, and ear nets, especially those treated with synthetic pyrethroids such as pyrethrin, permethrin, and deltamethrin. But note that these substances only protect the areas directly under the treated fabric.
  • Reduce exposure to the parts of the horse’s body that biting insects favor most: belly, legs, flanks, hindquarters, ears, and abrasion sites.

Take-Home Message

The study authors concluded that owners must do their research to learn which insects in their area are threats and tailor prevention approaches accordingly. With due diligence and careful management, you can significantly reduce the risk of your horse contracting VS

Create a free account with to view this content. is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into

Start your free account today!

Already have an account?
and continue reading.


Written by:

Diane Rice earned her bachelor’s degree in agricultural journalism from the University of Wisconsin, then married her education with her lifelong passion for horses by working in editorial positions at Appaloosa Journal for 12 years. She has also served on the American Horse Publications’ board of directors. She now freelances in writing, editing, and proofreading. She lives in Middleton, Idaho, and spends her spare time gardening, reading, serving in her church, and spending time with her daughters, their families, and a myriad of her own and other people’s pets.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from

Sponsored Content

Weekly Poll

sponsored by:

Has your veterinarian used SAA testing for your horse(s)?
54 votes · 54 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with!