Etiology. Syniploins. 199 



animals, after distemper or in the course of rachitis, etc. Older 

 dogs with tartar and caries of the teeth are affected most fre- 

 quently, particularly if they have been nourished insufficiently. 



The direct causes of tlie inflammation and of tlic subsecjuent tissue 

 necrosis are not known. The character of the morbid process points 

 to an infection as does likewise the experience that a simihir disease in 

 man frequently assumes an epidemic character. Tartar on the teeth 

 predisposes to infection in consequence of the loosening of the gums ; 

 anemia and cachexia act by diminishing the resistance of the tissues. 



It is possible that patliojicnic bacteria, wliieh are normally found in the saliva 

 may have part in the causation of the disease. Fiocea has demonstrated a bacillus 

 salivarius septicus and the staphylococcus pyogenes aureus in tlie saliva of dogs 

 and the l)acinus coli communis in the mouth of sucking eats. One also must think 

 of the presence of the bacillus necrophorus. However, inoculation of material 

 from sick into healthy animals has not been successful in transferring this disease 

 (Cadeac). 



Exceptionally a stomatitis which is primarily benign may 

 pass over into an ulcerative inflammation in consequence of 

 secondary specific infection. The disease also appears as a 

 part of the clinical picture of the infrequent scorbutus in dogs 

 and swine and of chronic hog erysipelas. (See Vol. I.) 



The disease is similar in its symptoms to inflammation of 

 the mouth seen in connection with mercurial poisoning after re- 

 peated inunctions with gray ointment or after excessive injec- 

 tions of corrosive sublimate (stomatitis mercurialis). (Accord- 

 ing to Cadeac 's experimental investigations, the real cause of 

 this affection is claimed to be the bacillus necrophorus.) Some- 

 times other agencies like lead, copper or phosphorus may have 

 a similar effect. 



Symptoms. The inflammation l)egins almost without ex- 

 ception at the margins of the gums, around the neck of the in- 

 cisors of canines, especially in the spaces between the individ- 

 ual teeth. The gums of the molars usually become aifected la- 

 ter. The gums at the affected places appear dark or sometimes 

 bluish-red, swollen, very painful, and on being touched l)leed l)ut 

 slightly. After one or two days, the free margins of the gums 

 become changed into a pale yellowish or dirty-greenish smeary, 

 mushy mass, which can easily be removed; the live tissue in 

 their neighborhood looks bluish-red and swollen. After the ex- 

 pulsion of the mushy masses, one sees, around the neck of the 

 teeth, ulcers with margins and bases covered by necrotic, dis- 

 colored detritus. The erstwhile round ulcers become confluent 

 forming an ulcerated discolored surface; the necks of the teeth 

 are left uncovered. After the process has spread into the 

 alveoli, the teeth become loosened and can be extracted easily, 

 or they may fall out spontaneously. 



In the further course similar ulcers are formed on the mu- 

 cosa of the lips and cheeks ; these ulcers are found opposite the 



