Foot and mouth disease (picornaviridae). This virus causes foot and mouth disease in cloven-hooved animals. Symptoms include a fever followed by the development of blisters on the feet and in the mouth. The virus is highly contagious, spreading by contact with infected animals and animal products, in the air and on materials exposed to infection. It is a picornavirus, and has an icosahedral (20-sided) protein coat (capsid, blue) surrounding its genetic material. The rapid spread of the disease can cause epidemics, requiring quarantining and slaughter of infected animals.