Foot-and-mouth disease or hoof-and-mouth disease (Aphtae epizooticae) is an infectious

Infectious disease

Infectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...

 and sometimes fatal viral disease

Disease

A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 that affects cloven-hoofed animals, including domestic and wild bovids. The virus causes a high fever for two or three days, followed by blisters inside the mouth and on the feet that may rupture and cause lameness.

Foot-and-mouth disease is a severe plague for animal farming, since it is highly infectious and can be spread by infected animals through aerosol

Aerosol

Technically, an aerosol is a suspension of fine solid particles or liquid droplets in a gas. Examples are clouds, and air pollution such as smog and smoke. In general conversation, aerosol usually refers to an aerosol spray can or the output of such a can...

s, through contact with contaminated farming equipment, vehicles, clothing or feed, and by domestic and wild predators.