Foot and mouth protection zone. Sign warning vehicles that they are approaching a protection zone. Protection zones are areas with restricted access, set up during the foot and mouth outbreak to help prevent the spread of disease. Foot and mouth is caused by viruses in the picornavirus group. It infects domestic and wild cloven-hoofed animals, causing fever followed by the formation of blisters in the mouth and on the feet. It is highly contagious, spreading by direct contact with infected animals and animal products, through the air and with the movement of contaminated equipment and people. Photographed at the National Trust's Runnymede Estate in Windsor, Surrey in September 2007.