608 DILATATION, ETC., OF RECTUM AND ANUS. 



VI.— CONTRACTION, DILATATION, STENOSIS, AND PARALYSIS OF 

 THE RECTUM AND ANUS. 



After operation for atresia ani, amputation of prolapsed portions 

 of the rectum, and injury to the anus, cicatricial contraction some- 

 times occurs, causing marked stenosis and difficulty in defalcation. 

 Sometimes the anus is completely closed, as in Johne's case, in a six 

 months old pig after ligation of the prolapsed rectum, or in Volk's 

 in a pig, where the same accident followed spontaneous sloughing. 

 Occlusion of the rectum occurs, both in pigs and dogs, in consequence 

 of chronic diarrhoea, particularly during the first years of life ; the 

 epithelium is lost, the opposing mucous surfaces become adherent, 

 and finally unite. 



Cicatricial contraction of the rectum may also result after injury 

 or ulceration of its mucous membrane, and cause stenosis, or new 

 growths, within or without the bowel, may compress it' and narrow 

 its lumen. 



Johow saw a cow which stood with the back arched and continually 

 attempted to defalcate ; a ring-shaped stenosis of the rectum existed at 

 the entrance to the pelvis, and was barely large enough to admit two or 

 three fingers ; the rectum was greatly distended in front of the spot, which 

 was about half an inch wide. After incising the stenosis and using 

 clysters, a cure was effected. The nature of the case seems obscure. 



Rogerson diagnosed in a mare and a foal, which both suffered from 

 stoppage of the bowel, well-marked stenosis of the rectum about 20 inches 

 in front of the anus ; the post-mortem examination showed the rectum 

 to be greatly thickened, of cartilaginous consistency, and to some extent 

 ossified. Johne saw the same condition in a cow, Meyer in a horse. Gurlt 

 found the rectum of a foal so narrow that only a strong goose-quill could 

 be passed through it. 



Pathological dilatations of the pelvic portion of the rectum are 

 not infrequent in horses. They are seldom partial — so-called diver- 

 ticula — but usually the entire pelvic portion is dilated. They are 

 oftenest seen in old horses which have long been fed on bulky food, 

 and in dogs which have suffered from habitual constipation or 

 enlargement of the prostate, which interferes with defalcation ; dogs 

 also show this dilatation in hernia perinealis. Old horses often 

 suffer from extensive dilatation of the pelvic portion without showing 

 distress, though they have difficulty in defaecation, especially if 

 paralysis of the rectum accompanies dilatation. 



Hengst speaks of an old horse which suffered from colic, and showed 

 a rectal sacculation 12 inches in front of the anus, which was the size of 

 two fists and filled with faeces. After emptying and washing this out. 

 the colic disappeared. Martin noted the formation of a diverticulum in 

 a horse after injury to the rectum ; 10 inches in front of the anus was a 

 wound about 6 inches long and 2 broad ; which caused severe fever and 



