Foot and mouth disease. Keep out signs and foot dip on a farm, precautions against foot and mouth disease virus contamination. This disease, caused by viruses in the picornavirus group, infects domestic and wild cloven-hooved animals, causing a fever and the development of blisters in the mouth and on the feet. It is highly contagious, spreading by contact with infected animals and products, in the air and on equipment exposed to infection. Animal movement restrictions and the disinfection of materials entering and leaving farms helps limit the spread of the disease. Infected farm animals are slaughtered and burnt to remove contamination. Photographed in early 2001.