Information About

Vesicular Stomatitis

for the Dairy Producer

Vesicular Stomatitis

Vesicular stomatitis is a sporadic, reemerging

viral disease characterized by vesicular lesions on

the tongue, oral mucosa, teats, or coronary bands of

cattle, horses, and swine. The disease also affects

sheep and goats. Many species of wild animals,

including deer, bobcats, goats, raccoons, and 

monkeys, are also susceptible. People who handle

infected animals also can become infected with 

vesicular stomatitis.

Vesicular stomatitis is most likely to occur during

warm months in the Southwest, particularly along

riverways and in valleys. The Southwestern United

States experienced a vesicular stomatitis outbreak

from May 1998 through January 1999.

Aside from its economic impact, vesicular 

stomatitis is significant because its outward signs are 

similar to (although generally less severe than) those

of foot-and-mouth disease, a devastating foreign 

disease of cloven–hoofed animals that was 

eradicated from the United States in 1929. The only

way to diagnose and differentiate these diseases is

through laboratory tests.

The U.S. Department of Agriculture's (USDA)

Animal and Plant Health Inspection Service (APHIS)

works to keep vesicular stomatitis from becoming

established in the United States because of its 

similarity to other diseases of concern, its negative

impact on livestock production, and its public health

implications. Vesicular stomatitis is a disease that

must be reported to the international animal health

community when an outbreak is discovered.

Individual countries may then take steps to restrict

imports of U.S. livestock during outbreaks. Exports

would be restricted to an even greater extent if 

vesicular stomatitis were allowed to spread in this

country.

Mode of Transmission

Vesicular stomatitis has been confirmed only in

North, Central, and South America. The disease is

endemic in the warmer regions of the Western

Hemisphere, but sporadic outbreaks occur in temperate geographic areas.

How vesicular stomatitis spreads is not fully

known; insect vectors, mechanical transmission, and

movement of animals may be responsible. Once

introduced into a herd, the disease moves from animal to animal by contact or exposure to saliva or fluid

from ruptured blisters.

Clinical Signs

The incubation period for vesicular stomatitis

ranges from 2 to 8 days. Infected animals suffer from

blisterlike lesions in the mouth and on the dental pad,

tongue, lips, nostrils, hooves, and teats. Mouth

lesions can be so painful that animals generally

refuse to eat or drink. Infected animals usually 

experience severe weight loss. Fever can occur

immediately before or at the same time lesions first

appear but is of short duration and thus is detected

rarely. The most common clinical sign in cattle is

drooling or frothing at the mouth.

Fever and decreased feed intake commonly

cause severe drops in milk production in dairy cows.

About 25 percent of infected dairy cattle suffer teat

lesions that can lead to mastitis. Foot lesions cause

lameness in less than 5 percent of infected cattle.

Vesicular stomatitis does not generally cause animals

to die.

The number of infected cattle in a herd varies.

Five to 10 percent of animals within an infected herd

typically show clinical signs, and up to 80 percent of

the animals in a herd may become infected. If there

are no complications, such as secondary infections,

infected animals recover in about 2 weeks. However,

the ulcers may take up to 2 months to heal, and 

healing animals may still spread the disease.

Human Health Risks

People who handle an infected animal can 

contract vesicular stomatitis if they fail to follow proper biosafety methods. In humans, vesicular stomatitis

causes an acute influenzalike illness with symptoms

such as fever, muscle aches, headaches, and

malaise. Vesicular lesions are rare in humans.

Prevalence in humans may be underreported

because the disease often goes undetected or is 

misdiagnosed. People who handle potentially infected

cattle should wear gloves to protect their hands and

should not allow saliva and blister fluids to come in

contact with open wounds or with their mucous 

membranes, such as the membranes in their eyes or

mouth. Producers and other individuals who handle

cattle and experience symptoms should contact their

physician immediately.

Factsheet

Veterinary Services November 2002

APHIS
Economic Impacts

In an effort to assess the financial impact 

vesicular stomatitis can have on dairy herds, New

Mexican dairy cattle owners were surveyed about the

1995 summer and fall outbreak in the Western United

States. Two dairies were identified as harboring 

vesicular stomatitis. The impact on one dairy was

minor, costing only $1,150. The main cost was the

extra feed needed for quarantined animals that could

not be marketed. The second dairy had 25 cows

infected with vesicular stomatitis. This dairy 

experienced drops in milk production and had to cull

all 25 cows. The total loss to this dairy was $24,664,

two-thirds of which was due to the culling.

Additional data on vesicular stomatitis economic

impacts were published in the Journal of the

American Veterinary Medical Association (Goodger,

W.J., Thurmond, M., and et al., volume 186: page

370-373; 1985). The study lists estimated losses per

cow due to vesicular stomatitis outbreaks in dairies in

various States. For instance, California Dairy A, $97;

Dairy B, $202; Idaho $123; Washington $194; and

Colorado $253. For the two California dairies (1,569

cows milked), per-cow losses translated into a total

loss of $225,000 in a 2-month period.

Also outlined in the study were six categories of

losses due to a 1982 vesicular stomatitis outbreak in

the San Joaquin Valley, CA. The following table shows

the categories and percentages of overall economic

losses.

Overall Loss Category (percent)

Increased culling 40-50

Reduced milk production 20-30

Increased mortality 10

Indirect losses from calf 7-8

mortality and quarantine

Early dry-off 3-4

Increased labor, medicine, 

and veterinary costs 3-4

Increased Culling—Losses from an increase in

culling were based on the cost of replacing an 

infected animal with one of similar genetic potential

less the salvage value (beef value) of the infected 

animal. Involuntary culling in large numbers took place

because of the number, severity, and rapid 

development of clinical cases. Infected animals were

debilitated and suffered severe weight loss, up to 400

pounds. Fewer cattle may have been culled if milking

was discontinued early to reduce stress.

Reduced Milk Production—Revenue lost from

the decrease in milk production was based on the 

difference between an average herd's milk production

before and during the outbreak. Milk production in

dairy cows with vesicular stomatitis varies depending

on where lesions are located on the animals.

Therefore, dairies that have a higher proportion of 

animals with teat lesions experience greater losses.

Increased Mortality—Economic losses from

higher mortality rates were based on any mortality

rate above normal for a particular dairy. The cost

included both replacing and rendering infected 

animals.

Calf Mortality—Because dairies are more 

concerned with reducing adult herd losses than caring

for quarantined calves, the increase in calf mortality

rates was not due to the disease. The maintenance of

quarantined calves and their feed were additional

costs.

Increased Labor, Medicine, and Veterinary

Costs—In addition to costs for medicine and 

veterinary services, more personnel were hired to

handle increased management responsibilities during

the outbreak.

Reducing Economic Losses

When a dairy herd becomes infected with 

vesicular stomatitis, producers can reduce economic

losses by implementing management practices that

will minimize the spread of the disease to susceptible

herdmates and effectively treat infected animals.

Producers also should take precautions to prevent

human infection.

Facilities and Equipment—Vesicular stomatitis

can spread rapidly within a herd through direct 

contact between animals, common feed and water

troughs, insects, and inanimate objects that can 

harbor the virus, including feeding equipment and

bedding. To maintain facilities and equipment 

hygienically, managers should

• Clean and sanitize feed bunks, water sources, 

and milking facilities daily.

• Rinse, disinfect, and rerinse calf buckets, nipples, 

and other utensils after each feeding.

• Use different boots or disinfectant footbaths when 

moving between clean and infected areas.

Phenolic- and halogen-based disinfectants work 

best (see the tabulation under "Effective 

Disinfectants"). Sunlight and heat also destroy the

virus quickly.

• Clean and sanitize feeding and cleaning 

equipment before using with healthy animals.

• Implement an animal and facility vector-control 

program.

• Maintain ground surface conditions that minimize 

the risk of foot injury. Foot skin integrity can be 

enhanced by routine bathing in antiseptic 

solutions.

• Maintain safe milking equipment to prevent teat 

abrasions and trauma: use soft liners; check and 

adjust the pulsation rate, teat-end vacuum, airflow,

and vacuum reserve; adjust automatic takeoffs to 

prevent over- or undermilking; carefully and 

gently remove units by cutting vacuum; adjust 

squeaky liners.
• Flush, wash, and/or scrape alleyways after each 

milking.

Feed—Feed cattle high-quality forage and soft

grains to reduce mouth injuries. Place concentrates in

a clean bunk on top of hay or silage. Do not feed

calves or other livestock colostrum from infected 

animals. Compost, ferment, or burn leftover feed daily.

Treatment—Producers should implement treatments to reduce secondary bacterial infection and

promote healing. Supportive care, such as adding

high-energy liquid gruel feed and electrolytes to the

water supply, is the single most important treatment.

Older, higher milk-producing cows in the early phase

of lactation are at highest risk of vesicular stomatitis

infection. Monitor these animals carefully. Consult a

veterinarian about which lesions to treat.

Uncomplicated, untreated oral ulcers usually heal in 2

weeks, and cows are back on feed within 7 days of

showing clinical signs. To hasten healing of infected

animals, implement the following treatments:

• Swab oral ulcers with a 1 to 2 percent solution of 

Lugol's iodine and with oral and injectable 

antibiotics, and observe appropriate antibiotic 

withdrawal periods.

• Spray foot ulcers twice daily with a saturated 

solution of copper sulfate.

• Treat teat ulcers with a spray solution of an 

antibiotic and antiinflammatory drug.

• Treat mastitic quarters by using an aseptic 

technique; predip teat, wipe with alcohol, and 

redip teat after infusion.

• Treat uncommon conditions such as ketosis and 

neurologic complications, which are possible con

sequences of a vesicular stomatitis infection.

• Consider infected animals for early dry-off to 

reduce stress and further debilitation and to 

prevent culling.

Prevention

Adding Cattle to a Herd—Cattle that are already

infected with vesicular stomatitis or that have been in

contact with infected animals can introduce it into

healthy dairy herds. Producers should ascertain that

new cattle come from sources that have not had 

animals with clinical signs of vesicular stomatitis in the

past 3 months. Producers should isolate newly arrived

cattle and calves from the rest of the herd for at least

21 days. The isolation area is ideally offsite and as far

away from the main herd as feasible.

Producers should exercise similar precautions to

avoid reintroducing vesicular stomatitis into a herd

that has just recovered from the disease. Cattle can

become reinfected with the virus after only a few

weeks.

Animal Movement—Intermingling infected and

healthy animals may contribute to the spread of vesicular stomatitis. Producers should take the following

precautions in limiting animal movement:

• Isolate infected animals and maintain them in an 

area physically removed from other cattle as soon

as signs appear.

• Minimize interpen movement of all animals.

• Remove calves from infected dams immediately, 

and keep these calves separated from others.

• Isolate dead animals for pickup by a salvage 

truck.

• Spray carcasses around the mouth, teats, and 

feet with disinfectant, and treat with insecticide.

• Avoid putting cattle into contact with livestock and 

other animals, such as dogs, cats, rodents, birds, 

and insects. The same rules apply here as for 

isolating new herd additions from the main herd.

The goal is to minimize or prevent the entrance of

any potential biological or mechanical vector of 

vesicular stomatitis into dairy units.

Controlling Insects—Preventive activities should

incorporate insect controls because insects are

thought to be vectors. Consult your veterinarian for

advice on selecting an insecticide approved for use

with lactating animals. In addition to animal and 

premises treatment, eliminate habitats favorable to

insect survival. For example, screen the windows of all

buildings where animals are housed, and eliminate

standing water and objects that attract insects.

Mechanical Transmission—Scientists suspect

that the vesicular stomatitis virus is transmitted also

by people or inanimate objects such as feeding or 

cleaning utensils and health-care equipment (needles,

nose tongs, etc.). Producers should take precautions

to avoid transfering equipment and personnel

between isolates and the main herd. Use separate

sets of equipment for each group wherever possible. If

equipment is shared, clean and disinfect it thoroughly

between uses at different dairy facilities. Also, clean

and disinfect feed bunks and water sources daily.

Personnel should shower and change clothing and

boots when moving between isolates and the main

herd. If production logistics permit, care for isolated

animals after the main herd to avoid cross-contamination.

Keep service personnel and other visitors entering

the dairy unit to an absolute minimum. Again, require

showers and clothes changes for these personnel. If

possible, prevent feed, delivery, supplies, and other

trucks from directly entering the dairy unit. Ask drivers

if they have visited other dairy facilities and if they

have taken appropriate cleaning and disinfecting 

precautions. Service personnel often visit multiple
dairy operations on any given day, and they and their

vehicles, shoes, clothing, and equipment represent a

potential source of disease transmission.

Farm vehicles that are used for transporting cattle

to slaughter or that are driven to places where other

cattle-hauling trucks and producers congregate should

be cleaned and disinfected. Drivers of these vehicles

should change contaminated clothing before returning

to their home base.

For footbaths and disinfection of facilities and

equipment, phenolic- and halogen-based disinfectants

work best. Sunlight and heat also destroy the virus

quickly.

Effective Disinfectants—The following table

shows disinfectants found to be effective in inactivating the vesicular stomatitis virus when used for 10

minutes.

Disinfectant Concentration

Chlorine bleach 0.645 percent

Wescodynetm 4 percent

Cresylic acids 1 percent

Roccaltm 1:200

Septisoltm 1:50

Vaccination—Vesicular stomatitis vaccines for

cattle have been available intermittently during outbreak years. However, little information is known about

their efficacy in preventing infection, reducing clinical

signs associated with infection, or lessening the economic impact of infection. Check with your State

Veterinarian's office for information on availability of

vaccines and permits that may be required.

Recommended Practices for Milking

Cattle

To enter and infect an animal, the vesicular stomatitis virus requires a break in the skin. Therefore, dry,

chapped, or cracked teats predispose cattle to infection. Producers should take measures to maintain or

restore healthy teat condition. Producers should not

use teat balm preparations on healthy teats because

the transmission of the virus may be enhanced and

secondary bacterial mastitis can develop. Infected animals that develop mastitis are often culled.

Milkers should wear rubber gloves and eye protection.

Milk healthy cows before infected ones.

Infected and Healthy Animals

• Prewash teats, if necessary, with diluted acid 

detergent and emollient to soften and remove soil.

• Clean and examine teats carefully.

• Daub teats dry with a soft paper towel.

• After milking, use iodine-based teat dip with a 

high concentration of emollient. Latex-based teat 

dips may provide a shield against virus entry.

• Use separate dip dispensers for infected and 

healthy animals.

• Dip milkers' gloves in tamed 4 percent iodine and 

rinse with water before milking the next animal.

• Dip liners in all units between every 2 or 3 

animals in tamed 4 percent iodine and rinse well 

with water. Dip liners also if a newly infected 

animal is inadvertently milked with the regular 

milking string.

• Empty, wash, and spray feed bunks and floors 

with disinfectant and rinse with water between 

strings.

Infected Animals

• Do not milk with the same milking string animals 

that are drooling, foaming at the mouth, or have 

new teat blisters. Place these animals with other 

infected animals and milk them last.

• Dip teats with new blisters in tamed 4 percent 

iodine and rinse with water before milking. Do not 

let the iodine dip enter the milk line.

• Spray painful ulcers with topical anesthetic 3 to 5 

minutes prior to attaching the milking equipment.

Blisters can develop into painful ulcers, resulting 

in poor milk letdown and difficulty in keeping the 

milking equipment attached. The administration of 

100 mg of oxytocin may be necessary to induce 

milk letdown.

• Perform a California mastitis test (CMT) on 

foremilk from quarters with teat lesions; if results 

are greater than a trace, treat with an 

extramammary antibiotic preparation used for 

lactating cows and observe appropriate 

withdrawal periods.

Impact on Reproduction

Vesicular stomatitis seems to have no direct

impact on reproduction. The virus is not known to

cause abortion or fetal resorption. In past outbreaks,

heat-detection efficiency suffered, but this appears to

be due to lack of management capacity rather than a

direct result of the disease. The number of cows

observed in heat may drop below 60 percent. The

impact of missed heats may persist over many

months as the average number of days in milk

increases, as does the average days open. If infected

cows become debilitated, they may experience

delayed uterine involution and subsequent delays in

the resumption of normal estrous cycles after calving.

Producers do not need to alter reproduction 

management practices during an outbreak, except to

make sure that the artificial insemination technician

does not spread the disease through mechanical

transmission. There is no evidence to suggest that the

virus can spread by artificial insemination or rectal

palpation other than by use of the contaminated

equipment.
Minimizing the Risk of Spread

Producers should take measures to minimize the

risk of spreading vesicular stomatitis through infected

cattle and calves' saliva and blister fluids. Temporarily

eliminating procedures involving the head and feet,

such as dehorning and foot trimming, should be 

considered. Delaying practices such as tattooing, 

vaccination (especially intranasal), removal of 

dewclaws or extra teats, administration of magnets,

and eartagging may decrease the spread of the virus

to herdmates.

Report Suspicious Cases

Vesicular stomatitis infection in a dairy herd can

cause significant financial losses. Implementing

appropriate, recommended management practices

and working closely with your veterinarian can reduce

the losses. 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.

Additional Information

For more information, contact

USDA, APHIS, Veterinary Services

Emergency Programs

4700 River Road, Unit 41

Riverdale, MD 20737-1231

Telephone (301) 734-8073

Fax (301) 734-7817

or visit our Web site at www.aphis.usda.gov/vs.

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United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture