Foot and Mouth Disease

Foot-and-mouth disease (FMD) is a severe and highly contagious viral disease. The 

FMD virus causes illness in cows, pigs, sheep, goats, deer, and other animals with 

divided hooves. It does not affect horses, dogs, or cats. FMD is not a public health or 

food safety threat. It is also not related to hand, foot, and mouth disease, which is a 

common childhood illness caused by a different virus.

FMD is a worldwide concern as it can spread quickly and cause significant economic 

losses. While many countries across the globe are dealing with FMD in their livestock 

populations, the United States eradicated the disease here in 1929. As part of our mission 

to safeguard American agriculture, the U.S. Department of Agriculture’s Animal and 

Plant Health Inspection Service (APHIS) works to ensure the continued health of our

Nation’s livestock. These efforts include preventing FMD from reentering the country.

What Is FMD?

Animals with FMD typically have a fever and blisters on the tongue and lips, in and 

around the mouth, on the mammary glands, and around the hooves. These blisters, called 

vesicles, pop and turn into red areas called erosions. Pain and discomfort from the 

vesicles and erosions lead to other signs of illness such as depression, anorexia, excessive 

salivation, lameness, and reluctance to move or stand. Most affected animals will not die 

from FMD, but the disease leaves them weakened and unable to produce meat and milk

the way they did before becoming sick.

FMD causes production losses and hardships for farmers and ranchers. It also has serious 

impacts on livestock trade—a single detection of FMD will likely stop international trade 

completely for a period of time. Since the disease can spread widely and rapidly and has 

grave economic consequences, FMD is one of the animal diseases livestock owners dread 

most.

What Causes FMD?

FMD is caused by a virus. After an animal is infected with the virus, the first signs of 

illness usually appear within 2 to 14 days.

The virus survives in living tissue and in the breath, saliva, urine, and other excretions of

infected animals. It can also survive in contaminated materials and in the environment 

for several months under the right conditions. Time, extreme temperatures, and pH 

changes will inactivate (i.e., kill) the virus.

There are 7 known types and more than 60 subtypes of the FMD virus. Immunity to one 

type does not protect an animal against other types or subtypes.

Animal and Plant

Health Inspection 

Service

May 2018
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How Does FMD Spread?

FMD can spread when infected animals bring the virus into physical contact with 

susceptible animals (i.e., divided hoof animals). An outbreak can also occur when

susceptible animals:

• Are held in contaminated facilities;

• Are moved in contaminated vehicles;

• Are fed raw or improperly cooked food waste containing infected meat or animal 

products;

• Have contact with people wearing contaminated clothes or shoes or using 

contaminated equipment;

• Are exposed to contaminated materials such as hay, feed, hides, or biologic 

products;

• Drink contaminated water; or

• Are inseminated with semen from an infected animal.

Signs of Illness

The best known signs of the disease include vesicles, which are similar to blisters, that 

quickly pop and cause erosions in the mouth or on the feet, resulting in excessive 

salivation or lameness. Because they pop quickly, these blisters are not always easy to 

see.

These signs may appear in affected animals during an FMD outbreak:

• Great increase in body temperature for 2 to 3 days

• Vesicles that rupture and discharge clear or cloudy fluid, leaving raw, eroded 

areas surrounded by ragged fragments of loose tissue

• Sticky, foamy, stringy saliva

• Eating less because of painful tongue and mouth blisters

• Lameness with reluctance to move

• Abortions

• Low milk production in dairy cows

• Heart disease and death, especially in newborn animals.

It will take many months for animals to regain weight lost during illness. Animals that 

recover seldom produce the same amount of milk as before, and conception rates may be 

lower.

Confusion with Other Diseases

Diseases involving blisters show similar signs. As a result, FMD may be confused with 

other vesicular but less harmful diseases, including vesicular stomatitis, bluetongue, 

bovine viral diarrhea, foot rot in cattle, and swine vesicular disease. The only way to tell 

if the vesicles are caused by the FMD virus is through laboratory testing. If you observe 

mouth or feet blisters or other typical disease signs in your animals, please report them 

immediately so that the appropriate testing can occur.
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Where FMD Occurs

While the disease is widespread around the world, North America, Central America, 

Australia, New Zealand, Chile, and many countries in Europe do not have FMD. Various 

types of FMD virus have been identified in Africa, South America, Asia, and some parts 

of Europe.

Prevention and Control

FMD is one of the most difficult animal diseases to control. Because the disease occurs 

in many parts of the world, there is always a chance of FMD being introduced into the 

United States. As a result, many animals and animal byproducts from areas known to be 

affected with FMD face import restrictions or are prohibited entry into this country. 

Livestock animals, including those in the United States, are highly susceptible to FMD 

viruses. If an FMD outbreak occurs here, the disease could spread rapidly to all regions

of the country through routine livestock movements—unless it is detected early and 

eradicated immediately. The economic impact of unchecked FMD spread could reach 

billions of dollars in the first year.

Vaccines for FMD are available, but must be matched to the specific type and subtype of 

virus causing the outbreak. In the event of an outbreak, animal health officials will 

carefully consider use of vaccination. If it becomes apparent at any point that a 

“stamping-out” strategy will not effectively eliminate the disease, we will immediately 

consider alternate strategies, including vaccination. It could then be used to help slow the 

spread of the FMD outbreak or to protect specific animals, depending on the situation. 

How You Can Help

There are many ways you can support our efforts against FMD:

• Watch for excessive salivation, lameness, and other signs of FMD in your herd.

• Immediately report any unusual or suspicious signs of disease to your 

veterinarian, State or Federal animal disease control officials, or your county 

agricultural agent.

• When traveling outside the United States, make sure that you do not bring back 

prohibited animal products or other at-risk materials.

If FMD appears in your animals, an eradication program will be initiated to protect our 

Nation’s livestock herd.

Your participation is vital. Both the early recognition of disease signs and the prompt 

notification of veterinary officials are essential to a successful eradication program. Your 

early reporting could prevent FMD from becoming established in the United States, or if 

it does spread, reduce the time and money needed to eliminate it.
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Additional Information

For more information about FMD, contact:

USDA APHIS 

Veterinary Services

District Offices

1-866-536-7593

Current information on animal diseases and disease outbreaks is also available on our 

website at www.aphis.usda.gov.