98 DISEASES OF THE MOUTH 



from infectious diseases. It is evidently an infectious dis- 

 ease, probably due to the Bacillus necrophorus. The lack 

 of resistance especially in young animals favors the develop- 

 ment of the organisms. Accumulations of filth in the kennels 

 and injuries to the tissues are predisposing causes". 



Pathology. — The gangrenous area has the appearance of a 

 corroded surface under which the mucous membrane seems 

 transformed into a dry, finely granular or firm mass. It is 

 grayish-yellow in color and bordered by a zone of thickened 

 tissue, slightly reddened and somewhat granulated. The 

 necrotic tissue is very adherent and can be only partially 

 peeled off. The condition may extend to the underlying 

 tissues and even involve the bones. 



Symptoms.— Slight salivation and a disinclination to take 

 food are the first symptoms noticed. An examination of the 

 mouth at this time may show an area of inflammation or 

 possibly an erosion. The latter rapidly increases in size and 

 depth, forming a sharply circumscribed, or at times diffuse 

 area of necrosis, which continuing to spread, may involve 

 any of the adjacent tissues. It often perforates the cheeks 

 forming a fistulous opening, or it may penetrate the hard 

 palate and produce a greenish-yellow nasal discharge. With 

 the involvement of the nasal passages, the larynx or trachea 

 respiration is disturbed. When life is prolonged for a week 

 or more, necrotic foci may be established in the lungs, giving 

 rise to symptoms of bronchopneumonia. As the disease 

 progresses, salivation becomes profuse, deglutition difficult 

 and the swollen tongue often protrudes from the open mouth. 

 A very offensive odor is exhaled. When the infection becomes 

 general (septicemia), the temperature is elevated (104°- 

 106° F.) and the animal shows extreme weakness. Diarrhea 

 is not uncommon and indicates an invasion of the gastro- 

 intestinal tract. 



Diagnosis.— This is made by the rapid spread of the disease 

 in the tissues of the mouth, fetid odor and the general 

 symptoms. 



Prognosis.— Ordinarily this disease shows no tendency to 

 a spontaneous recovery, and if untreated death usually 

 results. If taken early, however, it usually responds to 



