July 14, 2020

First Vesicular Stomatitis Virus case confirmed in Missouri horse


Today, Missouri State Veterinarian Dr. Steve Strubberg announced the state’s first case of Vesicular Stomatitis in a horse in Newton County. The announcement follows a positive confirmation from the United States Department of Agriculture’s National Veterinary Services Laboratory (NVSL), making Missouri the seventh state to confirm the virus this year. As a result, the Missouri Department of Agriculture is urging horse owners to monitor their livestock closely and call their veterinarian if symptoms arise.

All susceptible animals on the affected premises have been quarantined. The quarantine will continue for at least 14 days after the onset of lesions in the last affected animal. The Department has begun epidemiological work to trace back any possible sources of transmission; however, flies and midges are known to be vectors of the virus. As a preventative measure, Missouri has required a veterinary examination, Certificate of Veterinary Inspection (CVI) and an Entry Permit for hooved animals entering the state from affected areas.

Vesicular Stomatitis is a contagious, non-fatal virus that primarily affects horses and cattle by causing a fever and vesicular lesions in the mouth, on ears, near the coronary band of hooves or on teats. Horses infected with Vesicular Stomatitis may be treated with anti-inflammatory medication to minimize swelling and kept on soft feeds to ensure they continue eating and drinking. The virus occasionally affects other hooved livestock, including sheep, goats and swine. The virus has been confirmed in Arizona, Kansas, Nebraska, New Mexico, Oklahoma and Texas this year in both horses and cattle.



Accredited veterinarians will play a critical role in the rapid diagnosis of Vesicular Stomatitis in horses. Veterinarians can assist in collecting samples and submitting them for testing to the NVSL in Ames, Iowa. Although flies and other insects are the primary vectors for the virus, the Department encourages veterinarians to follow proper biosecurity measures as they travel to prevent spread between farms. Because of the confirmed case in Missouri, other states and Canada are likely to increase restrictions on livestock imports. Animal health officials strongly encourage all livestock owners and veterinarians to call the animal health authority in the destination location for the most current import requirements prior to travel.


Horse and Livestock Owners

All horse and livestock owners should enhance their existing biosecurity measures, including insect control programs, reducing contact between horses, and isolation protocols for horses returning to a farm. Owners should also clean and disinfect communal waterers, feed bunks, trailers and other livestock equipment regularly.


Hosts of Exhibitions, Trail Rides and Markets

The Department strongly recommends hosts of exhibitions, trail rides and markets require CVIs issued within 48 hours of arrival and a veterinary inspection upon arrival. If any horses or livestock exhibit suspicious symptoms consistent with Vesicular Stomatitis, the State Veterinarian recommends sending the animal home for isolation and testing. If adopted, these heightened recommendations may help keep horses and livestock healthy, and provide for continuity of farm and business operations. For official guidelines related to exhibitions, trail rides and markets, please click here.


Vesicular Stomatitis is a reportable disease. Individuals or veterinarians who suspect or have concerns about the virus should contact the Department at (573) 751-3377. To learn more about Vesicular Stomatitis, please click here. To view USDA’s latest situation report on the spread of the virus in 2020, visit USDA APHIS online.