APHIS Factsheet

Veterinary Services March 2007

Vesicular Stomatitis

Vesicular stomatitis is a viral disease that primarily 

affects cattle, horses, and swine and occasionally sheep, goats, llamas, and alpacas. Humans 

can also become infected with the disease when 

handling affected animals, but this is a rare event. 

Vesicular stomatitis has been confirmed only in the 

Western Hemisphere. It is known to be an endemic 

disease in the warmer regions of North, Central, 

and South America, but 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 in recent years. Outbreaks in the Southwestern United States have usually occurred during 

the warmer months, often along waterways and in 

valleys. In some years during outbreaks, only a few 

premises in a single State were affected. Typically, 

however, in most years with outbreaks, multiple 

States and many premises were involved. 

 Since there could be a vesicular stomatitis outbreak in any given year, it is essential that veterinarians and livestock owners be on the alert for animals displaying clinical signs for the disease. For 

current information on vesicular stomatitis outbreaks 

or summaries of the most recent past outbreaks, 

please visit our Web site

 <http://www.aphis.usda.gov/vs/nahss/equine/vsv/>.

 While vesicular stomatitis does not generally 

cause animals to die, it can still cause economic 

losses to livestock producers. The disease is 

particularly significant because its outward signs 

are similar to (although generally less severe than) 

those of foot-and-mouth disease, a foreign animal 

disease of cloven-hoofed animals that was eradicated from the United States in 1929. The clinical 

signs of vesicular stomatitis are also similar to those 

of swine vesicular disease, another foreign animal 

disease. The only way to tell these diseases apart 

is through laboratory tests. 

 Vesicular stomatitis is recognized internationally as a reportable disease. What this means is 

that there are serious economic and regulatory 

repercussions associated with the diagnosis. When 

the disease is detected in the United States, many 

countries take action to block international trade of 

U.S. animals. Interstate movement of animals is 

also impacted. Premises containing affected 

animals are quarantined until 21 days after the lesions 

in the last affected animals have healed. As a result, 

quarantine periods can be lengthy.

Clinical Signs

 In affected livestock, the incubation period for 

vesicular stomatitis ranges from 2 to 8 days. Often, 

excessive salivation is the first sign of the disease. 

Close examination of the mouth initially reveals 

blanched and raised vesicles or blister-like lesions 

in affected livestock. These blister-like lesions can 

form in the mouth and on the dental pad, tongue, 

lips, nostrils, hooves, and teats. The blisters swell 

and break, leaving raw tissue that is so painful that 

infected animals show signs of lameness and generally refuse to eat or drink. Severe weight loss may 

follow. Body temperature may rise immediately before 

or at the same time lesions first appear. Dairy cattle 

often suffer from teat lesions and subsequent mastitis; 

a severe drop in milk production commonly occurs. 

Some affected dairy cattle can appear to be normal 

with no clearly visible symptoms but may only eat 

about half of their normal feed intake. If there are no 

complications such as secondary infection, affected 

animals typically recover in about 2 weeks. 

 In horses, vesicular lesions generally occur on the 

upper surface of the tongue, the lips, around nostrils, 

corners of the mouth, and gums. Lesions in horses 

may also be expressed as crusting scabs on the muzzle, lips, or ventral abdomen. Affected pigs usually 

first show signs of lameness caused by foot lesions.

 How vesicular stomatitis spreads is not fully 

known; insect vectors, mechanical transmission, 

and movement of animals are all factors. Once the 

disease is introduced into a herd, it may move from 

animal to animal by contact or exposure to saliva or 

fluid from ruptured lesions. Humans rarely contract 

vesicular stomatitis, but they can become infected. 

In people, the disease causes an acute influenza-like 

illness with symptoms such as fever, muscle aches, 

headache, and malaise. To avoid exposure to this 

disease, individuals should use protective measures 

when handling affected animals. 

Recommended Actions

There is no specific treatment or cure for vesicular 

stomatitis. Owners can protect their animals from 

the disease by avoiding congregating animals in the 

vicinity where vesicular stomatitis has occurred. Mild 

antiseptic mouthwashes may bring comfort and more 

rapid recovery to an affected animal. Good sanitation 
United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, 

national origin, age, disability, and where applicable, sex, marital 

status, familial status, parental status, religion, sexual orientation, 

genetic information, political beliefs, reprisal, or because all or part 

of an individual’s income is derived from any public assistance 

program. (Not all prohibited bases apply to all programs.) Persons 

with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) 

should contact USDA’s TARGET Center at (202) 720–2600 (voice 

and TDD). To file a complaint of discrimination, write to USDA, 

Director, Office of Civil Rights, 1400 Independence Avenue, S.W. , 

Washington , D.C. 20250–9410 , or call (800) 795–3272 (voice) or 

(202) 720–6382 (TDD). USDA is an equal opportunity provider and 

employer. 

and quarantine practices on affected farms usually 

contain the infection until it subsides and soon ends.

 When a definite diagnosis is made on a farm, 

the following procedures are recommended: 

 • Separate animals with lesions from healthy 

 animals, preferably by stabling. Animals on 

 pastures apparently are affected more fre 

 quently with this disease.

 • As a precautionary measure, do not move 

 animals from premises affected by vesicular 

 stomatitis, unless they are going directly to 

 slaughter, for at least 21 days after the last 

 lesion has healed. 

• Implement on-farm insect control programs 

 that include the elimination or reduction 

 of insect breeding areas and the use of 

 insecticide sprays or insecticide-treated 

 eartags on animals.

 • Use protective measures when handling 

 affected animals to avoid human exposure 

 to this disease. 

Report Suspicious Cases

Veterinarians and livestock owners who suspect an 

animal may have vesicular stomatitis or any other 

vesicular disease should immediately contact State 

or Federal animal health authorities. Diagnosis of 

the disease cannot be made based on clinical signs 

but requires testing of samples at a facility approved 

by the U.S. Department of Agriculture’s National 

Veterinary Services Laboratories, Ames, IA. 

 A diagnosis can be based on antibody tests 

using fluid samples from the animal and/or by isolation of the virus from swabs of lesions, blister fluid, 

and tissue flaps. A diagnosis can be made within a 

few days for antibody detection or in slightly over a 

week for virus detection in swabs, fluids, and 

tissues.

Additional Information

For more information, contact the:

U.S. Department of Agriculture

Animal and Plant Health Inspections Service

Veterinary Services

Emergency Programs

4700 River Road, Unit 41

Riverdale, MD 20737-1231

Phone: (301) 734-8073