Foot and mouth disease (FMD) is a highly contagious viral disease that affects cloven-hoofed animals such as cattle, pigs, sheep, goats and other ungulates. This virus, belonging to the Aphthovirus genus of the Picornaviridae family, represents a significant threat to animal health, agricultural economy and food security in many regions of the world.

Characteristics

The foot-and-mouth disease virus (FMDv) is distinguished by its ability to transmit rapidly and its high resistance in the environment. It can survive on inert surfaces, in the air and in biological materials such as milk and excrement. There are seven serotypes of the virus (A, O, C, SAT 1, SAT 2, SAT 3 and Asia 1), which complicate effective immunization, since there is no cross-immunity between them.

Clinical signs

Animals infected by FMDv present symptoms such as:

• Vesicles: Appear mainly in the mouth, tongue, hooves and udder. When they break, the cause painful ulcers that make feeding and mobility difficult.
• Fever: Initially, animals may develop a high fever, which decrease when vesicles appear.
• Drooling and loss of appetite: due to oral pain.
• Lameness: due to lesions on the hooves.

These clinical sings vary in severity depending on the affected species and the virulence of the virus.

Transmission

FMD spread primarily by direct contact between infected and susceptible animals. However, it can also spread indirectly, through:

• Aerosols: the virus can be transported long distances in the air, especially in humid and temperate climates.
• Contaminated material: vehicles, clothing, agricultural equipment and people can act as vectors of transmission.
• Animal products: milch, meat and others of infected animals are potential sources of contagion.

Economic impact

The outbreak of FMD can have a devastating impact on the agricultural economy. The disease causes losses due to:

• Reduction in production: sick animals reduce milk and meat production.
• Trade restrictions: many countries impose barriers to the import of animal products from regions affected by FMD, affecting international trade.
• Eradication costs: animal culling, cleaning, disinfection and vaccination campaigns can be extremely expensive.

Control and Prevention

FMD control is based on a combination of sanitary, biological and legislative measures:

• Vaccination: it is one of the most effective strategies, especially in endemic regions. However, the need for specific vaccines for each serotype makes its implementation a challenge.
• Sanitary slaughter: in disease-free areas, when outbreaks are detected, infected and susceptible animals are slaughtered to stop the spread.
• Movement control: restricting the movement of animals and livestock products to and from affected areas is essential to prevent the spread of the virus.
• Biosecurity: hygiene and disinfection measures in farms and in transport are the key to reducing the risk of contagion.

Global situation

FMD is present in many parts of the world, mainly in Asia, Africa and parts of South America. However, some countries and regions have managed to eradicate the disease through control policies, as is the case in Europe, North America and Australia.

In Latin America, FMD has been a historical challenge, especially in countries such as Argentina, Brazil and Colombia. Thanks to intensive vaccination programs and control measures, several of these countries have been declared free of FMD with or without vaccination.

Conclusions

FMD remains one of the main threats to animal health and the livestock economy worldwide. While effective prevention and control strategies exist, the nature of the virus and its ability to spread rapidly require constant surveillance and international cooperation. The implementation of robust biosecurity plans and targeted vaccination programmes are essential to protect both animal health and the economic well-being of livestock producers.