APHIS Factsheet

Veterinary Services February 2007

Foot-and-Mouth 

Disease

Foot-and-mouth disease (FMD) is a severe, highly 

contagious viral disease of cattle and swine. It also 

affects sheep, goats, deer, and other cloven-hooved 

ruminants. FMD is not recognized as a zoonotic 

disease.

 This country has been free of FMD since 

1929, when the last of nine U.S. outbreaks was eradicated. 

 The disease is characterized by fever and blisterlike lesions followed by erosions on the tongue and 

lips, in the mouth, on the teats, and between the 

hooves. Most affected animals recover, but the disease leaves them debilitated. It causes severe losses 

in the production of meat and milk.

 Since it spreads widely and rapidly and because it 

has grave economic as well as clinical consequences, 

FMD is one of the animal diseases that livestock 

owners dread most.

What Causes It

FMD is caused by a virus. Signs of illness can appear 

after an incubation period of 1 to 8 days, but often 

develop within 3 days. 

 The virus survives in lymph nodes and bone marrow at neutral pH, but is destroyed in muscle when pH 

is less than 6.0, i.e., after rigor mortis. The virus can 

persist in contaminated fodder and the environment 

for up to 1 month, depending on the temperature and 

pH conditions.

 There are seven known types and more than 60 

subtypes of the FMD virus. Immunity to one type does 

not protect an animal against other types. 

How It Spreads

FMD viruses can be spread by animals, people, or 

materials that bring the virus into physical contact with 

susceptible animals. An outbreak can occur when:

• Animals carrying the virus are introduced 

 into susceptible herds.

• Contaminated facilities are used to hold 

 susceptible animals.

• Contaminated vehicles are used to move 

 susceptible animals.

• Raw or improperly cooked garbage containing 

 infected meat or animal products is fed to 

 susceptible animals.

• People wearing contaminated clothes or footwear, 

 or using contaminated equipment, pass the virus 

 to susceptible animals.

• Susceptible animals are exposed to materials 

 such as hay, feedstuffs, hides, or biologics 

 contaminated with the virus.

• Susceptible animals drink common source 

 contaminated water.

• A susceptible animal is inseminated by semen 

 from an infected animal.

Signs

Vesicles (blisters) followed by erosions in the mouth 

or on the feet and the resulting excessive salivation 

or lameness are the best known signs of the disease. 

Often blisters may not be observed because they 

easily rupture, leading to erosions. 

 These signs may appear in affected animals 

 during an FMD outbreak:

• Marked rise 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.

• Production of sticky, foamy, stringy saliva.

• Reduced consumption of feed due to painful 

 tongue and mouth lesions.

• Lameness with reluctance to move.

• Abortions.

• Low milk production (dairy cows).

• Myocarditis (inflammation of the muscular walls 

 of the heart) and death, especially in newborn 

 animals.

 Animals do not normally regain lost weight for 

many months. Recovered cows seldom produce milk 

at their former rates, and conception rates may be low.

Confusion With Other Diseases

FMD can be confused with several similar but less 

harmful diseases, such as vesicular stomatitis, 

bluetongue, bovine viral diarrhea, foot rot in cattle, 

and swine vesicular disease. Whenever mouth or 

feet blisters or other typical signs are observed and 

reported, laboratory tests must be completed to 

determine whether the disease causing them is FMD 

or not.

Where FMD Occurs

While the disease is widespread around the world, 

North America, Central America, Australia, New 

Zealand, Japan, Chile, and many countries in Europe 
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. 

are considered free of 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 infections to 

control. Because the disease occurs in many parts of 

the world, there is always a chance of its accidental 

introduction into the United States. 

 Animals and animal byproducts from areas known 

to be affected are prohibited entry into this country.

 Livestock animals in this country are highly susceptible to FMD viruses. If an outbreak occurred in 

the United States, this disease could spread rapidly to 

all sections of the country by routine livestock movements unless it was detected early and eradicated 

immediately.

 If FMD were to spread unchecked, the economic 

impact could reach billions of dollars in the first year. 

Deer and other susceptible wildlife populations could 

become infected and potentially serve as a source for 

reinfection of livestock.

 Vaccines for FMD are available, but must be 

matched to the specific type and subtype of virus 

causing the outbreak. Vaccination can help contain 

the disease if it is used strategically to create barriers 

between FMD-infected zones and disease-free areas. 

What You Can Do

You can support U.S. efforts against FMD by:

• Watching for excessive salivation, lameness, and 

 other signs of FMD in your herd; and

• Immediately reporting any unusual or suspicious 

 signs of disease to your veterinarian, to State or 

 Federal animal disease control officials, or to your 

 county agricultural agent.

• When traveling outside the United States, ensur- 

 ing that you do not bring back prohibited 

 animal products or other at-risk materials (see 

 APHIS Factsheet on Protecting America from 

 FMD).

 

If FMD should appear in your animals, your report will 

set in motion an aggressive State and Federal 

eradication program. 

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

veterinary officials are essential if eradication is to be 

carried out successfully. Your warning may prevent 

FMD from becoming established in the United States, 

or, if it does spread, reduce the time and money 

needed to wipe it out.

Additional Information

For more information about FMD, contact:

 USDA, APHIS, Veterinary Services

 National Center for Animal Health Emergency 

 Management

 4700 River Road, Unit 41

 Riverdale, MD 20737–1231

 Phone: (301) 734–8073

 Fax: (301) 734–7817

 Current information on animal diseases and dis- 

 ease outbreaks is also available on the Internet at 

 <http://www.aphis.usda.gov>.