Within 24 to 48 hours it enters the bloodstream, causing fever. During this phase, lasting 24 to 36 hours, the virus is excreted in the saliva, the milk, the urine, and the faeces. A characteristic smacking of the lips then usually becomes prominent in the infected animal, ushering in the phase of the formation of vesicles on the tongue, gums, and lips of the mouth. These vesicles rupture in about 24 hours, leaving raw, inflamed, and extremely painful surfaces that heal in one to two weeks. By this time the animal refuses to eat solid food.
Blisters also appear on the foot, causing lameness.
The losses caused by foot and mouth disease are tremendous. In those animals that survive, great losses in weight occur because the animals cannot eat. In surviving milk-producing animals the flow of milk is sharply diminished. Abortions and mastitis are common, and secondary infections are frequent. Foot and mouth disease is endemic throughout much of Europe, Asia, Africa, and South America.