The link between human and animal populations, and the surrounding environment, is particularly close in developing regions where animals provide transportation, draught power, fuel, clothing, high-quality proteins (meat, eggs and milk) and source of income. Therefore, animal health is a core element for sustainable development and livestock production. 

As changes in livestock production increase the potential for new pathogens to emerge, grow and spread from animals to humans, healthy animals are closely related to healthy people and a healthy environment. Through the One Health approach, FAO contributes to improving animal health to make livestock production more productive and sustainable while achieving optimal health for all at the human-animal-environment interface.