304 FOOT AND MOUTH DISEASE 



The mouth is usually kept closed and the quantity of saliva is 

 increased. A smacking sound is not infrequently made by the 

 animal. These symptoms are chiefly due to the pain accom- 

 panying the disease in the mouth. After two or three days 

 the eruption appears. This consists of small yellowish-white 

 vesicles or blisters varying in size from a hemp seed to a pea 

 •on the gums and inner surface of the lips, the inside of the 

 cheeks, the border and under the surface of the tongue. They 

 may become half an inch or more in diameter. In some cases 

 the back of the tongue near the tip may be the seat of large 

 blisters. 



These vesicles burst soon after their appearance, some- 

 times on the first day. More rarely they may persist for two 

 or three days. After they have ruptured the greyish-white 

 membrane forming the blister may remain for a day or more 

 ■or disappear speedily and leave deeply reddened areas or 

 erosions which are very painful. These exposed areas may 

 soon become covered again with the normal epithelium or they 

 may be converted into ulcers. In this stage the .saliva forms 

 in large quantities and hangs in strings from the mouth. In 

 eight to fourteen days the disease may have entirely disap- 

 peared. 



In addition to the changes in the mouth, one or more feet 

 may become diseased. The skin around the coronet and in 

 the cleft between the toes becomes hot and tender and may 

 swell. Blisters appear as in the mouth, but they are speedily 

 ruptured and the inflamed, exposed areas are covered with a 

 viscid exudate. 



The udder, more particularly the teats, may be the seat 

 of lesions. Some authorities regard the udder disease merely 

 at she result of infection during milking. The vesicles are 

 broken as they appear by the hands of the milker and the 

 teats become covered with reddened areas, deprived of the 

 superficial layer of the skin and are very tender. The heal- 

 ing, however, goes on quite rapidly. The milk is said to be 

 somewhat changed in appearance and unfit for making butter 

 or cheese. These are the main symptoms accompanying the 

 uncomplicated cases of foot and mouth disease. In all such cases 



