Symptoms. 339 



the seat of the vesicles, and healing occurs only after the shedding of 

 the same (Born). Russian veterinarians (Ravitsch, Korsak, Michai- 

 low, Schadrin) have also observed in some outbreaks the appearance of 

 such pseudo-membranous deposits but only in strong animals, and in 

 these eases vesicles were not present, or only in an abortive development. 



Simultaneously with, the, affection of the mucous membrane, 

 similar vesicles develop, in cattle on the muzzle and at the base 

 of the horns (rarely), in hogs on the snout (frequently), which 

 may reach the size of a nut, and correspond with the described 

 vesicles (on the snout sometimes only a single large vesicle 

 develops). Vesicles may also be observed in rare cases on the 

 nasal mucous membrane, and. on the conjunctiva. The spread- 

 ing of the affection to the pharyngeal mucous membrane is indi- 

 cated by symptoms of a pharyngitis (difficulty in swallowing, 

 cough, regurgitation). In cattle the cornea is sometimes uni- 

 formly cloudy, and small vesicles may develop on its surface. 

 The ulcerations which, subsequently develop heal w'ithout leav- 

 ing a trace, or white cicatrices may remain, which however later 

 disappear partly. In some instances vesicles may also develop 

 on tlie epiglottis, on the mucous membrane of the trachea and 

 bronchi, in which cases difficulty in respiration, or manifesta- 

 tions of edema of the lungs may be noticed (Leyendecker). 



Foot Affection. Sheep are quite frequently and hogs are 

 in most instances affected only on the feet, whereas in cattle 

 affection of the feet may occur simultaneously with the forma- 

 tion of lesions in the mouth, but it usually develops subsequent 

 to their appearance. 



The first symptom, which may be recognized even from a 

 distance, is always the lameness or the stiff gait, which is 

 caused by the pain in the lower extremities, and is especially 

 manifested during walking on hard ground. If more than one 

 foot is affected the pain may be so severe that the animals lie 

 down continually, and it is only with difficulty that they can 

 be made to rise. 



A careful examination of the affected feet reveals the skin 

 of the coronary band, the heel of the foot, and the interdigital 

 space at first warm, swollen, painful, and in_case it is not pig- 

 mented it appears also highly reddened. After 1 to 2 days, small 

 vesicles develop in these places, especially in the interdigital 

 space, more rarely also at the base of the dew-claws, which soon 

 reach the size of a hazelnut, and are filled first with a clear, 

 and later with a cloudy fluid. After their bursting, which at 

 these places results earlier than in the mouth, owing to the 

 continuous friction, the lymph-like fluid, together with the dirt 

 from the ground, dries to brown crusts. If they are removed, 

 the underlying surface shows sore places, which are desqua- 

 mated of epithelium, highly reddened, moist, and very sensitive. 

 The formation of new epithelium under the scab progresses 



