THE DIGESTIVE SYSTEM 53 



the tissues during its attachment. There may also be 

 muscular twitching. 



Treatment. These parasites are difficult to dis- 

 lodge. Long-continued medication with creosote alter- 

 nated with copper sulphate has proved effectual in many 

 cases. 



Tumors 



Intestinal tumors are not prevalent and are of little 

 economic importance. 



Connective tissue tumors may develop and mechani- 

 cally interfere with intestinal movement or they may 

 obstruct the lumen of the bowel. Fibromas and myxomas 

 have been observed, usually having their origin in the 

 subserosa or within the serous coat of the intestine. 

 These tumors are definitely encapsulated. It is usually 

 not possible to make a diagnosis except by autopsy. 



Of the malignant tumors, carcinoma, epithelioma, 

 adenoma, and different varieties of sarcoma have been 

 identified. The embryonic epithelial tumors may be 

 primary or secondary. Primary epithelial tumors usually 

 have their origin in or from the mucous membrane. 

 Secondary epithelial tumors may involve any portion 

 of the intestinal wall and are more frequently encapsu- 

 lated than the primary tumors. The primary epithelial 

 tumors, especially epitheliomas, are very prone to pro- 

 duce necrosis of the surface mucous membrane and thus 

 cause ulceration. 



General sarcomatosis of the entire abdominal viscera 

 is occasionally observed. Sarcomas in swine are appar- 

 ently not so malignant as in other domesticated animals, 

 and are more frequently encapsulated. The appearance 

 of the various malignant tumors in swine is the same or 

 very similar to that of the same type of tumor in other 

 animals. 



Intestinal malignant tumors, generally speaking, are 

 evidenced by unthriftiness, indigestion, emaciation, ma- 

 rasmus, and finally by death. 



