Foot and Mouth Disease and other Vesicular Diseases

 

Other names

Foot and Mouth Disease - FMD

Swine Vesicular Disease - SVD

Vesicular stomatitis-VS Vesicular Exanthema of Swine and San Miguel Sea Lion Viruses

Causal agent

Foot and Mouth Disease - Virus Picornovirus (Aphthovirus)

Swine Vesicular Disease - Virus Picornovirus (Enterovirus)

Vesicular stomatitis - Virus - Rhabdovirus (Vesiculovirus)

Age group

All ages of pigs can be affected

Clinical signs

Foot and Mouth is the definitive disease, the other diseases present with similar signs which may be confused with foot and mouth

 

Incubation period 1 to 5 days but can be 21 days

Fever to 40.5C

Skin around the snout, lips, tongue, inside the mouth, around the coronary band and the soft skin on the feet becomes whiter (blanched). Vesicles may develop on the sow's teats

Vesicles (blisters) develop

Vesicles rupture up to 24 hours after development and if no secondary infection occurs healing is rapid

The animals are lame. Lesions in the mouth may not occur obviously in the pig

With the feet, the hoof may become detached, revealing the painful raw tissues underneath. The hoof can re-grow, but is often deformed. This can take several weeks

The disease affects nearly all susceptible animals, but few animals will die specifically with the disease

One day un-ruptured vesicle on the snout

Ruptured vesicle on the snout

Horn separation

Ruptured vesicles and some hoof separation

Blanched un-ruptured vesicle

Vesicles on feet

Pig lame with FMD


 

Infectivity of Foot and Mouth

 

Affects all cloven-hoofed animals - pigs, cattle, sheep and goats. VS also affects horses

Rapidly spread through the air, animal contact and vectors, such as clothing, utensils, vehicles

Can be spread through meat and meat-by products, especially fast frozen feeds

Spread through semen

High humidity, cloud cover and moderate temperatures favour airborne spread (over 20 km)

Pigs produce aerosols 3000 times more concentrated than cattle

Carrier status occurs in cattle. FMDv can be excreted in the milk for up to 7 weeks

Post-mortem lesions

 

Vesicles, generally ruptured, in the mouth, nose and on the feet

Treatment and control

Treatment

Notify your vet and government official if clinical signs are suspected

None. In endemic areas a vaccine is used

Control

Strict regulation of importation of animals and animal products infected with vesicular diseases

Euthanasia and disposal of animals- burial, composting, rendering or burning

Zoonotic implications

 

Human infection does occur but is extremely rare, often without any clinical signs