Foot-and-mouth disease (FMD) is one of the most highly contagious diseases of animals. The disease is distributed on three continents (Asia, Africa and South America) where it disrupts the food security of people who depend on livestock and animal products. Substantial economic losses are associated with controlling FMD outbreaks in many countries. For example, during the epidemic in the UK in 2001, losses to agriculture were estimated to be £3.1 billion, with similar losses arising from negative impacts on tourism. Over 4 million animals were slaughtered as part of FMD control measures and a further 2 million were slaughtered due to welfare issues associated with animal movement bans. FMD also has a devastating impact on rural livelihoods and livestock trade opportunities in developing countries where it is endemic. In Africa, historic patterns of FMD virus (FMDV) emergence are likely to have been shaped by the introduction and subsequent eradication of rinderpest.