The Britannica Encyclopedia writes a good entry about Foot-And-Mouth Disease (http://www.britannica.com/EBchecked/topic/212824/foot-and-mouth-disease-FMD), the most economically devastating livestock disease in the world. Because the virus is so easily transmitted, ranchers and even governments must go at great length to contain outbreaks. They do this by disinfecting automobiles, cleaning roads, and monitoring traffic. Although this disease is not common in the United States, it is what ranchers in Latin America and the world fear the most.