Foot and Mouth Disease
Vesicular lesions of the muzzle...
genus aphtovirus, 7 types and several subtypes
highly contagious and one of the most feared diseases, is
endemic to Asia, Africa, parts
of Europe and South America. Because the disease is
easily transmitted and spreads rapidly, outbreaks cause
enormous financial losses in terms of production and
export revenue, and costs of eradication and vaccination
Cloven hoofed livestock such as cattle, pigs, sheep and goats as well as several wild animals (deer, water buffaloes, bears, antelopes, llamas, camels, giraffes, elephants, rats, hedgehogs) of all ages and sexes are susceptible to infection. Men in very rare cases may develop very mild forms of disease. Horses are resistant.
FMDV is resistant to cold temperatures and survives even freezing, but it is susceptible to pH less than 5, sunlight, heat and dryness.
Transmission is either via aerosol from animal to animal, or contaminated personnel, equipment or feed. Wind may spread the virus over long distances. Occasionally, it is imported to FMD-free countries by contaminated frozen meat or garbage. Several outbreaks could be traced to consumption of uncooked waste (swill feeding) from ships or airplanes originating from FMD-infected countries. Even contaminated biologicals (MLV vaccines against hog cholera, Rinderpest or insufficiently inactivated FMD vaccines) have been a source of infection in the past.
In cattle, the primary site of infection are mainly the nostrils, following inhalation of aerosols. The virus replicates there, gains access to the bloodstream and infects the epithelium of mouth, feet, rumen and teats as well as the heartmuscle especially in young animals. Large amounts of virus are shed before clinical signs develop and thereafter.
Morbidity approximates 100%, mortality ranges from 5% (adults) to 75% (young stock). Surviving animals remain virus carriers for up to two years. These carrier animals will shed the virus without showing any clinical signs.
an incubation period of 2 to 21 days (in most cases 3 to
5 days), infected animals develop fever, depression,
nasal discharge and anorexia. Excessive lip smacking,
which is one ot the pathognostic symptoms to be heard,
and salivation due to vesicular lesions of the tongue,
buccal and oral cavity are characteristic signs. Blisters
(0,5 to 3 cm in diameter) may also appear on the muzzle,
teats, udder, pili of the rumen, interdigital area and
coronary band. They contain a straw colored fluid, are
painful and cause anorexia and lameness in affected
Two to 3 days after appearance the blisters rupture, leaving denuded areas, erosions and painful ulcers.
Frequently, the healing is delayed by secondary bacterial infection of the wounds. Severe forms of mastitis, bronchopneumonia and lameness may occur subsequent to the initial viral infection. Abortion and weight loss as well as a drastic decline of milkproduction are common.
Calves up to 6 months and piglets up to 2 months frequently develop fatal myocardial degeneration and die within a few days without showing any other clinical signs.
...of the tongue...
following signs should be considered as possible FMD
infections: highly contagious diseases among cattle and
pigs, vesicular lesions, erosions and ulcers of the oral
cavity, throat, teats, coronary band and interdigital
area, lameness, fever, abortions, sudden drop of milk
yield and sudden death of calves, lambs or piglets.
Contact state authorities immediately.
Collect and submit samples of vesicular fluids, tissue samples of the blisters, blood serum and esophageal secretions in suitable containers to confirm the clinical findings. Tissue culture, ELISA, virus neutralization, complement fixation, or agar-gel precipitation are used for detection and typing of virus and antibodies.
||Vesicular stomatitis, bovine papular
stomatitis, bovine herpes mammilitis, bluetongue, severe cases of IBR, BVD/MD, pseudocowpox, rinderpest, malignant catarrhal
in cattle, SVD (swine vesicular disease) in pigs and
footrot in sheep
...and of the interdigital area
International Animal Health Code of the OIE contains the criteria
for a country or zone to be listed as FMD free. There are
free countries with and without vaccination.
programs are favored in countries with a low incidence of
disease. The success depends on the thoroughness that is
paid to the following points:
vaccination programs in a form of a blanket vaccination
are favored in countries with a high incidence of disease,
where eradication does not seem possible in the near
future. The enormous number of animals saved from
stamping out and the prevention of losses due to clinical
disease may outweigh the costs of vaccination programs.
However, in very rare cases and depending on the quality
of the vaccine, unexpected expenses may be caused by the
occurrence of adverse reactions to vaccination (especially
in pigs) and immunity breakdowns of individual animals.
prohibited in several countries, because eradication
programs demand the slaughter of affected animals.
Treatment must be avoided even in countries where it is
not prohibited, because treated animals shed high amounts
of virus and are a very high risk for all remaining
animals. If allowed, systemic antimicrobial drugs, mild
disinfectants, immunomodulators and protective
dressings are recommended to prevent secondary bacterial
infection, alleviate the signs and strengthen the immune
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