THE DIGESTIVE SYSTEM 31 



INTESTINES 



Malformations 



Total absence of the intestine is rare and occurs 

 practically only in acardiac monsters. 



Atresia ani, that is, the failure of development of the 

 anus, is relatively common. This condition results from 

 the failure of invagination of the skin surface which 

 normally extends to and fuses with the rectum. Pigs so 

 affected, unless the defect is relieved by operation, die 

 the first or second day after being farrowed. The 

 defect is as a rule easily corrected by operation in which 

 crucial incisions are made through the skin and the 

 terminal end of the rectum, the skin and rectal triangular 

 flaps being interdigitated and maintained by sutures. 



Cloacal formation in which there is a common opening 

 for the intestine, uterus, and vagina or ureters sometimes 

 occurs, but this is not a serious defect, except in breeding 

 animals. 



Diverticula are not rare. They are usually the per- 

 sistent remnants of the vitellin or omphalomesenteric 

 duct. They do not as a rule interfere with the health of 

 the animal. 



Transposition, particularly of the large colon, may 

 occur, but is not of any significance except as a pathologic 

 condition. 



Congenital hernia may occur. The outcome depends 

 upon the extent and nature of the defect. 



Hemorrhage (Enterorrhagia) 



Enterorrhagia occurs rather commonly in swine. 



Etiology. Mechanical injury of the structure of the 

 intestine by ingested foreign bodies is a common cause of 

 hemorrhage. In extreme cases of constipation the 

 accumulated fecal matter may become so desiccated 

 that it readily produces abrasions of the intestinal mucosa, 

 resulting in hemorrhage. Parasites, particularly the 

 Gigantorhynchus hirudinaceus, may also produce hemor- 

 rhage. Intestinal hemorrhage is a common symptom of 



