22 



DISEASES OF THE DIGESTIVE APPARATUS. 



development is perhaps favored by particular individual con- 

 ditions abnormally vulnerable, a lack of resistance of the mucous 

 membrane acting in connection with an infection. In certain 

 cases decayed teeth, or teeth covered with tartar, are the starting- 

 point of the disease in producing an infectious gingivitis ; never- 

 theless, the morbid process may start at a spot quite distant from 

 the teeth. 



We shall study ulcerative stomatitis due to mercury, lead, 

 phosphorus, etc., in the section treating of Poisons. 



We have never noticed this disease in an enzootic or contagious 

 form, though Hackbarth has observed it in an enzootic condition 

 upon horses pasturing in hybrid clover fields. Rivolta and Berndt 

 have also described a very malignant ulcerative stomatitis in 

 lambs, produced by Polydesmus exitiosus (Berndt) or bacteria 

 (Eivolta). 



Symptoms in the dog". The first signs are always localized 

 on the gums. Their edges are of a dark-red color, and more or 

 less tumefied near the incisors and canine teeth. After one or two 

 days the tumefaction will have spread and the gums will show a 

 spongy consistence; they are detached and bleed on the least 

 friction. A little later all the diseased tissues, and especially the 

 swollen gums, become greenish or yellowish -gray ; phlegmasia 

 progressing, the mucous membrane becomes partially necrotic. 

 The mortified spots look spongy ; they are of a glue-like, pulpy 

 substance. If they should be removed suddenly or artificially it 

 leaves an ulcer of one or two millimetres around the canine teeth 

 with irregular cut edges, and forming a hard, dark-red, protruding 

 swelling; the inside of the wound is irregular, and has a bad 

 appearance. A thick thread of saliva, sometimes bloody or 

 saneous, runs out of the mouth, staining the lips, nose, and cheeks. 

 The cavity of the mouth often contains a large quantity of saliva, 

 escaping when the jaws are distended, a movement which the 

 dog tries to avoid. The saliva, the cavity of the mouth, and the 

 expired air are of a fetid, cadaverous odor, which can be smelled 

 at some distance. 



The lesions upon the gums which have just been described can 

 also be found on the lips, in the gingivo-buccal fold, on the labial 

 commissures, more rarely on the cheeks, and exceptionally upon 

 the lower surface of the tongue. The sores on the lips are often 

 opposite those of the gums, which suggests an auto-infection ; at 



