Foot and mouth disease protein. Computer artwork of the surface topography of a protein from the foot and mouth disease virus. The virus causes foot and mouth disease in cloven-hooved animals. Symptoms include a fever and the development of blisters on the feet and in the mouth. It is highly contagious, spreading by contact with infected animals and animal products, in the air and on materials exposed to infection. The rapid spread of the disease can cause epidemics, requiring quarantining and slaughter of infected animals.