Foot-and-Mouth Disease (FMD)
Source: USDA, Veterinary Services March 2001
Foot-and-mouth disease (FMD) is a severe, highly communicable
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 blister-like
lesions followed by erosions on the tongue and lips, in the mouth, on
the teats, and between the hooves. Many affected animals recover, but
the disease leaves them debilitated. It causes severe losses in the production
of meat and milk.
Because 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
How It Spreads
FDM Signs
Confusion with Other Disease
Where FMD Occurs
Prevention and Control
What Farmers Can Do
More Sources
What Causes
It
COPY: The disease is caused by a virus. The virus survives in lymph nodes
and bone marrow at neutral pH, but destroyed in muscle when in pH<6.0
i.e. after rigor mortis. The virus can persist in contaminated fodder
and the environment for up to one month, depending on the temperature
and pH conditions.
There are at least seven separate types and many 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:
- People wearing contaminated clothes or footwear or using contaminated
equipment pass the virus to susceptible animals.
- 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.
- 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 cow is inseminated by semen from an infected bull.
Signs
Vesicles (blisters) followed by erosions in the mouth or on the feet and
the resulting excessive salivating or lameness are the best known signs
of the disease. Often blisters may not be observed because they easily
rupture, leading to erosions.
Some of these other signs may appear in affected animals
during an FMD outbreak:
- Temperatures rise markedly, then usually fall in about 2 to 3 days.
- Ruptured vesicles discharge either clear or cloudy fluid and leave
raw, eroded areas surrounded by ragged fragments of loose tissue.
- Sticky, foamy, stringy saliva is produced.
- Consumption of feed is reduced because of painful tongue and mouth
lesions.
- Lameness with reluctance to move is often observed.
- Abortions often occur.
- Milk flow of infected cows drops abruptly.
- Conception rates may be low.
- Meat animals do not normally regain lost weight for many months. Recovered
cows seldom produce milk at their former rates. FMD can lead to myocarditis
(inflammation of the muscular walls of the heart) and death, especially
in newborn animals.
Confusion
With Other Diseases
FMD can be confused with several similar, but less harmful, diseases,
such as vesicular stomatitis, bluetongue, bovine viral diarrhea, and foot
rot in cattle, vesicular exanthema of swine, 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.
Where FMD
Occurs
While the disease is widespread around the world, North America, Central
America, Australia, New Zealand, Chile, and some countries in Europe are
considered free of FMD. Various types of FMD virus have been identified
in Africa, South America, Asia, and part 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 infected 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 wildlife populations
could become infected rapidly and could be a source for reinfection of
livestock.
What You
Can Do
You can support U.S. efforts against FMD by:
- Watching for excessive salivating, lameness, and other signs of FMD
in your herd.
- 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.
- If FMD should appear in your animals, your report will set in motion
an effective 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, please contact:
USDA, APHIS, Veterinary Services
Emergency Programs
4700 River Road, Unit 41
Riverdale, MD 20737-1231
Telephone (301) 734-8073
Fax (301) 734-7817
The APHIS Emergency Operations Center
Toll-free Number: 1-800-940--6524
Email: emoc@aphis.usda.gov
Current information on animal diseases and suspected
outbreaks is also available on the Internet at http://www.aphis.usda.gov.
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