CHAPTER XL 



DISEASES OF THE RECTUM AND ANUS. 



Examination. —These parts are quite readily examined in 

 all small animals. The anus by inspection and palpation 

 for enlargements and abscess formation in the anal glands, 

 congenital occlusion in puppies, pseudocoprostasis, inflam- 

 mation at the anal opening, foreign bodies and parasites. 



The rectum is best examined as follows: (a) Direct 

 palpation. The index finger is inserted as far as possible to 

 determine the condition of the mucosa, the presence of 

 foreign bodies, parasites, fecal matter, blood, etc. (6) A 

 rectal speculum is used to dilate the anus and rectum. By 

 using reflected light (mirror) the mucosa can be directly 

 examined for inflammations, tumors, parasites, foreign bodies 

 etc. (c) Palpation through the abdominal walls will admit 

 of an examination of the anterior portion of the rectum. It 

 can easily be distinguished from the other tissues, and quite 

 readily inspected in this location for fecal accumulations, 

 foreign bodies, etc. (d) Laparotomy when performed just 

 anterior to the pubis, in the median line of females, and to 

 either side of the penis in males, will allow direct inspection 

 of the rectum for inflammations, tumors, fecal accumula- 

 tions, etc. 



OCCLUSION OF THE RECTUM AND ANUS. 



(o) A congenital occlusion of the rectum and anus has been 

 observed quite frequently in puppies. Imperforate anus is 

 most common. This condition exists at birth and is the 

 result of improper development during fetal life. The rectum 

 is formed from the hypoblastic and mesoblastic embryonic 

 layers while the anus is developed by the invagination of the 

 epiblastic which, as the development progresses, joins the 

 rectum by absorption of the intervening septum. Anything 



