216 DISEASES OF THE RECTUM AND ANUS 



HEMORRHOIDS. PILES. 



Definition. Hemorrhoids are varicose or dilated veins of 

 the hemorrhoidal plexus. According to their location they 

 are termed external, internal or mixed. External hemor- 

 rhoids are located outside the sphincter ani and in the sub- 

 cutaneous tissue, while internal hemorrhoids are located 

 inside the sphincter muscle and under the mucous membrane. 

 The mixed variety consists of both of the above appearing 

 at the same time. 



Etiology. This condition is commonest in old dogs, and 

 results most frequently from obstructions to the portal 

 circulation, through constipation, congestion of the liver, 

 proctitis, enlarged prostate glands, or chronic cardiac dis- 

 eases. All of these conditions, from a defective circulation 

 to the parts involved, lead to a venous stasis with a resultant 

 distention of the veins of the hemorrhoidal plexus. 



Pathology. The external variety is usually made up 

 chiefly of hypertrophied perirectal connective tissue, appear- 

 ing as small cutaneous projections, involving the external 

 veins, which become distended or rupture, forming a soft 

 tumor-like mass. The internal variety consists of numerous 

 distended vessels, increased connective tissue formation, 

 which often show an ulcerating surface, and are sometimes 

 found projecting through the anal opening. Hemorrhages 

 often take place readily from them, through irritation by the 

 passage of fecal material. 



Symptoms. The act of defecation is usually very painful, 

 the feces being covered with blood, or a quantity of blood 

 passed following the feces. Sometimes defecation is stopped 

 entirely from the severe pain which is induced by it. Pruritus 

 is also a prominent symptom, the animal biting or licking the 

 parts, or sliding the anus along the floor. Direct inspection 

 of the parts reveals the presence of the hemorrhoidal enlarge- 

 ments, which appear as bluish-red knots encircling the rec- 

 tum. If external, the enlargements will be noticed on e ther 

 side of the anal opening. Hectal examination is very painful 

 (different from rectal polypi, or other neoplasms, which are 

 occasionally found in this location). 



