Foot-and-mouth disease (FMD) is a highly contagious viral disease of cattle, buffalo, pigs, goats and sheep. The occurrence of FMD is associated with serious consequences for the affected countries. Wild cloven-hoofed animals such as deer, antelopes, wild boar, as well as camels, giraffes and elephants can also become infected. Horses are not susceptible to FMD; human infection (in occupationally exposed persons) may occasionally occur but does not usually lead to disease.

The foot-and-mouth disease virus (FMDV) is almost worldwide in distribution, with only New Zealand having no recorded FMD outbreaks to date. The disease is endemic in Africa, Asia, the Middle East and parts of South America. Other regions may experience sporadic outbreaks: for example, FMD in Europe has occurred twice in the 21st century in the UK (2001 to 2002 and 2007).

Cattle, buffalo and pigs

Transmission occurs through direct contact with infected animals, their products (e.g. milk, meat, semen) and excreta or contaminated inanimate objects. Airborne transmission is possible over considerable distances (up to 60 km over land).

2 to 14 days

General symptoms in all affected species are small ulcers (aphthae) on the udder, claws and mouth; fever (40-42 °C), pain, apathy, lameness and decrease in milk yield. Morbidity can reach 100%. The death rate is usually low in adult animals (up to 5 %), but can be 20 % or more in young calves, lambs and piglets.

Vaccination is prohibited in the EU. Diseased animals must be killed.

Detection, isolation and eradication of infected FMD-positive animals; control of animal movements to prevent the spread of the disease.

The last outbreak of foot-and-mouth disease in Austria was in 1981.

Foot-and-mouth disease is a notifiable animal disease. In case of suspicion of the disease, the official veterinarian has to initiate an immediate ban on the holding and a suspect investigation. Cases of disease in individual animals that show symptoms reminiscent of FMD (mostly skin changes), on the other hand, are quickly clarified in the course of exclusion examinations without a farm being closed. Nevertheless, the official veterinarian must be consulted in this case as well. In 2020, FMD was investigated in two cases in the course of exclusion tests, and a further 36 samples from zoo animals were tested for FMDV antibodies.

FMDV is a non-enveloped RNA virus belonging to the genus Aphtovirus of the family Picornaviridae with currently a total of 7 serotypes, with numerous subtypes within each serotype. Historically, the 7 serotypes are designated A for "Allemagne", O for department "Oise", C, Asia 1 for the first Asian detection, and SAT 1-3 for "South African Territories". Some viral strains are specifically adapted to pigs; other species may play a role in the spread of infection, but their importance as reservoirs is uncertain. The pathogen typically shows high affinity for epithelial tissue:

• Epitheliotropism: skin and cutaneous mucous membranes.
• Myotropism: skeletal and cardiac muscles
• Neurotropism (very rare): nerve tissue

General symptoms in all affected species are the formation of aphids (small ulcers) on the udder (teat, resistance to milking equipment), on the claws (interclaw cleft, coronary band, in pigs aphids up to the tarsal joint, reluctance to move, clattering, slow standing up) and in the mouth (inside of lips, tongue, gums, animals salivate and show reduced appetite); fever (40-42 °C), pain, apathy.

Other symptoms in cattle: decrease in milk yield, high mortality rate in calves.

Further symptoms in pigs: changes in the hoof/extremities often very severe, shoeing possible, deaths in piglets without clinical symptoms frequent.

Further symptoms in sheep: mainly fever. Lameness and lesions in the mouth area are often mild. Peracute deaths in young animals.

FMD is clinically indistinguishable from other vesicular diseases (e.g. vesicular viral disease of pigs, vesicular stomatitis), appropriate laboratory diagnosis or exclusion of the disease by laboratory tests is therefore essential. Suitable sample materials are:

• Epithelium of unruptured or freshly ruptured vesicles (aphthae) in dry, sterile screw-top vials, or in suitable transport medium (see below).
• Vesicle contents in dry, sterile screw tubes
• Esophageal/pharyngeal fluid (so-called probang specimens) in dry, sterile screw tubes, or in suitable transport medium (see below)
• Whole blood (Attention: Whole blood alone is not sufficient for diagnosis due to the short viremia; tissue, vesicle content, or probang samples must also be examined!)

The shipment of the sample materials should be carried out as quickly as possible after notification (ideally with coolants) in compliance with the relevant transport regulations (UN3373) and by a suitable logistics company to the investigating laboratory. The detection of FMDV from the above materials is possible with the following methods:

• Molecular biological identification with RT-PCR (vesicle epithelium, vesicle fluid, probang samples, serum).
• Antigen ELISA (vesicle epithelium, vesicle fluid)
• Serological test methods for antibody determination: ELISA, serum neutralization test (serum)
• Virus culture (vesicle epithelium, vesicle fluid, probang samples, serum): for virus isolation from aphthae material or probang fluid, this must be sent in an appropriate buffered transport solution, which can be obtained from the laboratory.
• Serotyping, or further pathogen characterization:
  • Antigen ELISA
  • Serotype-specific RT-PCR
  • Sequencing
  • Serotype-specific ELISA
  • Serum neutralization test