Vesicular Stomatitis Virus (VSV)

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What is VSV?

VSV is a viral disease that primarily affects horses, also cattle and occasionally swine, sheep, goats, llamas, and alpacas. Although humans can also become infected with the disease when handling affected animals, resulting in flu-like symptoms, this is a rare event. Vesicular stomatitis is known to be an endemic disease in the warmer regions of North, Central, and South America, and outbreaks of the disease in other temperate geographic parts of the hemisphere occur sporadically. The Southwestern and Western United States have experienced a number of vesicular stomatitis outbreaks, including a significant outbreak in 2015. Outbreaks usually occur during the warmer months, often along waterways. VSV is a state reportable disease. VSV was last isolated in the U.S. during the 2019 VSV outbreak, when eight states including Kansas reported confirmed VSV cases.

News Releases

Weekly situation reports from the U.S. Department of Agriculture Animal and Plant Health Inspection Service can be accessed by visiting the USDA website.

Vesicular Stomatitis Information

Vesicular stomatitis clinical signs

What should I do if I see symptoms?

Call your veterinarian immediately. VSV is a reportable disease.
Separate affected animal(s) from all healthy animals on your property.
Controlling insects (fly spray, fly traps, maintaining clean pens, etc.) is essential to reducing the risk and the spread of this disease.
Handle all healthy animals before sick animals. After handling sick animals make sure to wash and disinfect your hands and boots. If possible, change and wash your clothes as well.

Vesicular stomatitis treatment

Vesicular stomatitis is treated with supportive care. Since the lesions may be quite painful your veterinarian may prescribe anti-inflammatory drugs. If your animal is having trouble eating, softening their grain in warm water could encourage higher consumption. Softening hay cubes can also help if they are having trouble eating grass/hay. Secondary infections may develop at erosion sites and systemic antibiotic therapy may be warranted.

What should horse and livestock owners do to protect their animals?

Strict fly control in and around buildings.
- Manure management and elimination of fly breeding areas.
- Appropriate insecticide use and application for horses, barns, and outdoor areas.
Do not share equipment, tools or tack.
Avoid any comingling with animals which may be infected.
There are no USDA-approved vaccines for VSV.

How is vesicular stomatitis transmitted?

VSV is spread by insects and by direct contact with infected animals.
Black flies, sand flies, and midges are the known vectors of this disease, but other insects may also be capable of transmission.
Infected animals shed the virus from the lesions (blisters) they develop, so direct contact with infected animals or water, feed, buckets, and other fomites contaminated with saliva from infected animals can also transmit the disease.
The virus can also be spread on shoes, clothing, hands, and contaminated equipment, so follow good biosecurity practices and change or wash your clothing and boots after exposure to sick animals.

Are humans susceptible to VSV?

Health certificates for interstate travel

Information for the Veterinarian

Will this impact horse shows, rodeos, other gatherings and events?

2020 VSV Outbreak

On June 16, 2020, the Kansas Department of Agriculture confirmed a finding of vesicular stomatitis virus (VSV) in horses in Butler County, Kansas. Several other states also confirmed cases of VSV in 2020, including Arizona, Arkansas, Missouri, Nebraska, New Mexico, Oklahoma and Texas.

VSV was confirmed on 101 premises in 26 Kansas counties: Allen, Bourbon, Butler, Chase, Cherokee, Coffey, Cowley, Crawford, Elk, Franklin, Greenwood, Harvey, Johnson, Labette, Linn, Lyon, Marion, Miami, Montgomery, Morris, Neosho, Riley, Sedgwick, Sumner, Wilson, and Woodson. Details can be found in the situation report at the bottom of this page.

KDA actively responded to more than 270 premises with animals showing clinical signs consistent with VSV. All infected premises were placed on quarantine for a minimum of 14 days from the date of the last diagnosis.

VSV in Kansas - Star Map