THE DIGESTIVE SYSTEM 17 



formly tumefied, dense and hard. In either case the 

 epithelium of the mucous membrane becomes atrophied, 

 leaving only a thin covering, usually of a squamous 

 type of epithelium. 



Phlegmonous pharyngitis is not infrequently associated 

 with phlegmonous stomatitis, although it may occur 

 independently. Streptococci are the usual cause of 

 phlegmonous pharyngitis, and the lesions are practically 

 identical with those of phlegmonous stomatitis. 



Diphtheritic pharyngitis is not rare in swine. It is 

 the result of the Bacillus necrophorus, and practically 

 the same lesions are observed as in necrobacillosis. 



Paralysis 



Paralysis of the pharynx is a condition resulting 

 from disturbances of the controlling pharyngeal nerves 

 or of the muscles of the pharynx. This condition is 

 usually associated with rabies, although it has been 

 observed independent of that disease and probably 

 resulted from the influences of some substance upon the 

 deglutition centers of the medulla. 



Tumors 



Pharyngeal tumors in swine are not very common. 

 Occasionally polypoid fibromas are observed, but they 

 are rare. Of the malignant tumors the epitheliomas 

 are most often met with; however, these are rare. 

 Adenomas and carcinomas also have been observed, but 

 infrequently. 



ESOPHAGUS 



Malformations 



Malformations of the esophagus are rather rare. 

 The canal may end abruptly at the lower end. of the 

 upper third, beginning lower down, and continue to the 

 stomach, or the esophagus may form a union with the 

 trachea. In rare instances fistulous openings have been 

 observed in the cervical region. 



