348 ACUTE EXANTHEMATOUS INFECTIOUS DISEASES 



The large blisters rupture in about one day, leaving behind an 

 excoriated surface of a brown-red color, which is often covered 

 with a gray deposit. The smaller vesicles persist for two or 

 three days. On the back of the tongue one to three walnut- 

 sized vesicles are often noted. As the organ is extremely sore 

 and therefore little moved, the blisters remain intact for two 

 or three days. The contents of the vesicles are clear or 

 yellowish. Where they erupt a very sensitive, highly red- 

 dened, shallow erosion is left which becomes covered with new 

 epithelium in two or three days. When healing is well under 

 way the eroded area appears as a brown-yellow spot which 

 eventually disappears. As soon as the erosions are sufficiently 

 covered with epithelium the emaciated patient begins to eat. 



In some cases the muzzle (snout of swine), base of the 

 horns (very rare), nasal mucous membrane, conjunctiva, 

 pharynx (dysphagia, cough, regurgitation) and even the 

 cornea are similarly involved. 



The foot lesions induce lameness with knuckling of the 

 fetlock of the limb attacked. If two or more feet are af- 

 fected the patient lies down most of the time and is made to 

 arise with difficulty. The coronet is hot and swollen, espe-. 

 cially in front and between the bulbs of the heels. In some 

 cases the swelling extends up the leg to the middle of the 

 canon. On the second or third day of the attack pea- to 

 bean-sized vesicles appear in the swollen area. The vesicles 

 rupture very early and leave behind sores covered with a 

 tough, brown scab. Healing usually requires one or two 

 weeks. In severe cases, from secondary infection, shedding 

 of the claws results. 



In swine and sheep only the feet may be attacked, no 

 mouth lesions being apparent. 



In cows the skin of the teats and udder is often affected, 

 most often the former. The vesicles are from the size of a 

 pea to a hazel nut and are generally ruptured during milking. 

 The teats are swollen, sometimes phlegmonous (secondary in- 

 fection) and extremely sensitive. Later the sores become 

 covered with scabs and heal. 



Catarrhal mastitis frequently attends the exanthema, lead- 

 ing to changes in the milk, which becomes colostral, has an 



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