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Foot-and-Mouth
Disease: A Devastating Threat
AUBURN, MARCH 20---Livestock producers in
Alabama and the rest of the nation watch the evening news with
dread. The outbreak of foot-and-mouth disease in Europe means the
slaughter of thousands of animals and the potential destruction of
the area's livestock production.
And there is the very
real risk that the disease could enter the United States.
An Auburn University
professor of veterinary medicine says foot-and-mouth disease (FMD)
is a severe, highly communicable viral disease of cattle and swine.
"It also affects
sheep, goats, deer, and other ruminants, both domesticated and
wild," says Dr. Dwight Wolfe, a professor of large animal
medicine at Auburn University. "In an FMD outbreak, large
numbers of exposed animals may contract the disease, but most will
not die from the disease. Many affected animals recover, but the
disease leaves them debilitated, and it causes losses in the
production of meat and milk."
Because it spreads
widely and rapidly and because it has grave economic as well as
physical consequences, Wolfe says FMD is one of the animal diseases
that livestock owners worldwide fear most.
"In general, the
only way to stop an outbreak is to first quarantine and then destroy
any animals that may have come in contact with infected
animals," says Wolfe. "An animal begins to show signs
anywhere from 3 to 5 days after being infected."
Dr. Wally Hester, USDA's
area veterinarian in charge, says stopping all movement of livestock
is also crucial.
"Eighty-five
percent of all outbreaks can be traced directly to animal movement
or product movement," says Hester, who is based in Montgomery.
"If you stop all shipment or movement of livestock immediately,
you are still behind the curve with this disease because of the
speed with which it spreads. Additionally, the virus in serum or in
other organic material will survive drying and can be carried on
inanimate objects."
The state veterinarian's
office is working closely with USDA to prevent the disease from
entering Alabama. USDA and state veterinarians are reviewing
decontamination of equipment and other materials imported from
countries with FMD at the State Docks in Mobile. USDA inspectors are
working at international airports in Alabama and other cities across
the country to check passengers and luggage coming from infected
areas.
Foot-and-mouth disease
is caused by a virus, and symptoms include fever and blister-like
lesions in the mouth and on the teats and feet.
The virus has a
remarkable capacity for remaining viable in carcasses, in animal
byproducts, in water, in such materials as straw and bedding and in
pastures.
"The virus can even
live in the respiratory tracts of humans for up to 24 hours,"
says Wolfe. "If a person with the virus in the nasal passages
comes into contact with livestock, the virus could be transmitted to
the animals. However, it won't make a human sick."
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. A single infected animal or one contaminated sausage
could carry the virus to American livestock.
Animals in this country
are highly susceptible to FMD. They have not developed immunity to
it because FMD has not occurred here since 1929 and because U.S.
veterinarians do not vaccinate against it.
"Vaccinations have
never been used in the United States," says Hester.
"That's partly because of the many types of the disease."
There are at least seven
separate types and 63 subtypes of the FMD virus. Animals may be
affected by one or more of these at the same time. Recovered animals
may suffer repeated attacks of the disease because immunity to one
type does not protect an animal against the others.
If an outbreak were to
occur in the United States, this disease could spread rapidly to all
sections of the country by routine livestock movements unless
detected early and eradicated immediately.
If FMD were to spread
unchecked, the economic impact could reach billions of dollars in
the first year. The nation's deer and other wildlife populations
could also rapidly become infected and remain a reservoir of
infection.
The disease is
widespread. The virus has been identified in Africa, South America,
Asia and Europe.
North America, Central
America, Australia, New Zealand, Japan, Chile and some countries in
Europe are considered free of FMD because governments there have
conducted effective programs to prevent its introduction or to
eradicate it.
FMD can be spread by
animals, people or materials that bring the virus into physical
contact with susceptible animals. An outbreak may occur when:
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People wearing
contaminated clothes or footwear or using contaminated equipment
pass the virus to susceptible animals.
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Animals carrying the
virus are introduced into susceptible herds.
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Contaminated
facilities are used to hold susceptible animals.
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Contaminated
vehicles are used to move susceptible animals.
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Raw or improperly
cooked garbage containing infected meat or animal products is
fed to susceptible animals.
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Susceptible animals
are exposed to materials such as hay, feedstuffs, hides or
biologics contaminated with the virus.
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Susceptible animals
drink contaminated water.
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A susceptible cow is
inseminated with material from an infected bull.
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(For more
information, contact Margaret Lawrence, 334-844-5687.)
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