CONTAGIOUS STOMATITIS OF THE HORSE 353 



The disease is generally introduced into a stable or pasture 

 by an infected animal. 



Symptoms. — The period of incubation is three to five days. 

 The first symptoms noted are usually impairment of appetite 

 and ptyalism. The patient holds the mouth shut; if opened 

 a quantity of saliva spills out. The saliva is very viscid and 

 hangs in long threads from the mouth. The lips and cheeks 

 are somewhat swollen and tender. On examination of the 

 mouth, which the patient often resists, the mucosa appears 

 congested and streaked with red. On the mucous surface of 

 the lips, gums, the hard palate and particularly beneath the 

 tongue about the frenum appear firm-red papules the size of 

 a pea. The papules do not all erupt at the same time, but 

 successively, a fresh crop appearing after two or three days. 

 From the papules vesicles form. The smaller vesicles break 

 and heal while the larger ones turn to pustules which perfo- 

 rate, leaving behind small round ulcers. Sometimes two or 

 more ulcers coalesce forming large irregular areas of ulcera- 

 tion. The ulcers usually heal in a few days, leaving behind 

 a white scar. 



In some cases the pustular eruption may involve the lower 

 part of the nasal mucosa especially of the wings of the nostrils. 

 Nasal discharge may be present which dries and adheres as 

 brown crusts to the borders of the alee. In rare instances the 

 lacrimonasal canal is invaded, the infection spreading through 

 it to the conjunctiva. 



Sometimes the external skin is involved. There appear on 

 the lips, nostrils and cheeks papules, vesicles and pustules like 

 those observed on mucous membranes. Cases are recorded 

 where the eruption appeared on other parts of the body 

 (breast, shoulder, thigh). 



The lymph vessels and glands adjacent to the eruption fre- 

 quently swell, the vessels forming cord-like strands. There is 

 no tendency, however, for abscesses to form along their course 

 as in strangles. The submaxillary lymph glands are swollen. 



Diagnosis. — The diagnosis is usually not difficult. If the 



case is at all typical, it is exceedingly easy. The contagious 



character of the disease and the formation of papules ending 



in pustules and ulcers is indicative. In vesicular stomatitis, 



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