Often blisters may not be observed until they have ruptured. Temperatures rise markedly, especialy in young animals, then usually fall in about 48 hours. Ruptured vesicles discharge either clear or cloudy fluid and leave raw, eroded areas surrounded by ragged fragments of loose tissue. Sticky, foamy, stringy saliva is produced. Consumption of feed is reduced because of painful tongue and mouth lesions.
Abortions often occur.
Milk flow of infected cows drops abruptly. Conception rates may be low. Meat animals do not normally regain lost weight for many months. Recovered cows seldom produce milk at their former rates. The disease is widespread.