142 BOVINE PATHOLOGY. 



tagious influences, the incubation lasts from twenty-four 

 hours to four days ; and the first appreciable alteration of 

 the normal conditions of the animal is a gradual rise in 

 temperature. This may be so marked that the ther- 

 mometer at the maximum may reach 107° F. Shivering 

 and other febrile signs are present in the first stage of 

 the disorder, the mouth is sore and has hanging from it 

 a little viscid mucus, the animal does not feed, grinds its 

 teeth, and exhibits general signs of ill health, the bowels 

 are constipated, and the breath fostid. This lasts for 

 about two days, and then the characteristic eruptions 

 appear. In the mouth they occupy the dental pad, the 

 gums, lateral parts and dorsum of the tongue and the 

 palate; generally rounded or oval, they are of consider- 

 able size, averaging about that of a shilling, but often as 

 large as half-a-crown. They consist of elevations of the 

 somewhat dense epithelium, which is softened and macerated 

 by the saliva, and so rendered white. Soon they are 

 broken by the action of the tongue and other influences, 

 and a red raw surface is exposed. The discharge of 

 saliva is now profuse, and hangs in shreds from the mouth, 

 or collects like foam around that opening. There is a 

 peculiar smacking of the lips to get rid of this. Some- 

 times smaller vesicae appear on the transitional membrane 

 of the muffle, and in some cases the nostrils are similarly 

 diseased. There are vesicles developed on the udder in 

 milch cows, which especially affect the teats, and some- 

 times the diseased action is said to involve even the 

 lining membrane of the milk ducts. These mammary 

 vesicles are ruptured by the calf, or their contents 

 become absorbed and a dark brown scab remains, and 

 aggregation or confluence of these vesic99 may take place. 

 The lesions of the feet are preceded by pain, manifested 

 by restlessness, frequent lifting and shaking of fore and 

 hind feet, and the back is arched and thus all four feet 

 brought together. Swelling of the coronet appears, and 

 is quickly followed by the development of vesicae, gene- 

 rally between the digits, but often extending almost all 

 round the coronet. There is considerable lameness. 



