Vesicular Stomatitis (VS), also known as sore mouth of cattle and horses, is an important disease in livestock. With the recent outbreaks in Colorado, New Mexico, Texas, Wyoming and now Oklahoma, we felt the need to inform our clients about this disease.
What is it?
VS is a viral disease that can affect cattle, horses, pigs, and occasionally South American camelids. Sheep and goats can develop clinical signs but this is uncommon. Humans can also become infected with VS when handling affected animals although this event is rare. This disease is typically seen in the warm summer months and often along waterways.
How does it spread?
Transmission of VS is not completely understood but insect vectors appear to play a major role in the spread of this disease. These can include sand flies, blackflies, Culicoides midges, mosquitoes, eye gnats and even grasshoppers. Once it has been introduced into a herd, VS spreads through direct contact between affected animals. Broken skin or mucous membranes may facilitate entry of the virus. This virus has also been known to spread via contaminated fomites such as food, water and milking equipment.
Cattle presenting with VS have vesicles, papules, erosions, and ulcers mainly in and around the mouth, coronet band or interdigital spaces, udder/teats, and prepuce/sheath. Commonly, excessive salivation is the first sign the animal is infected. Lesions can also be present on the gums and palate. It is clinically indistinguishable from several other vesicular diseases including foot-and-mouth disease (FMD).
In horses, lesions can also be found in the ears as well as on the tongue and lips. Fever, drooling, reluctance to eat and lameness are often associated with these lesions because they are very painful. This is a self-limiting disease and deaths are very rare in both cattle and horses. VS is more common in horses compared to cattle due to horses traveling more often for shows, training, sales, etc.
Treatment and Control
VS is a reportable disease in North Dakota and if suspected, a state veterinarian will be notified. Vesicular stomatitis virus can be found in vesicle fluid, swabs of ruptured vesicles, the skin over un-ruptured vesicles, and skin flaps from freshly ruptured vesicles. The virus can be cultured and identified using immunofluorescence, complement fixation or ELISAs to detect viral antigens. VS can also be diagnosed using serology with paired serum samples. Good sanitation and disinfection with 1% sodium hypochlorite (bleach) or 40-70% ethanol can reduce the spread of the virus on fomites. Fly control is a must! Vaccines are not available in the U.S.
Treatment of VS is symptomatic. Cleaning the lesions with a mild antiseptic solution may aid healing and reduce secondary bacterial infections. If mouth lesions are causing the animal not to eat, provide softened feed to encourage intake.
From the ND Board of Animal Health
“All imports of horses, cattle, sheep, goats, swine, and cervidae from any states which have a confirmed Vesicular Stomatitis positive animal since the beginning of each calendar year, are required to be accompanied by a pre-entry permit number prior to import into North Dakota.”