While walking my dog, I noticed that when she went to the bathroom, blood was dripping from her rectum. What could cause this and does she need to see a veterinarian right away?
Generally, gastrointestinal tract bleeding is characterized as upper or lower GI bleeding. Upper GI bleeding usually produces a dark, tarry stool (melena); lower GI bleeding (from the colon, rectum, or anus) yields hematochezia, or red blood in the stool. Unclotted red blood dripping from the rectum suggests a problem in the rectum or anus, although colonic disease may produce hematochezia as well.
The appearance of blood after defecation may indicate a serious problem, but not always. The blood may be originating from the rectum, or possibly from the area of the anal sacs, which contain glands around the anus that normally release a portion of their contents with each defecation.
Dogs with anorectal disease or anal sac disease may have bleeding associated with defecation. Frequently there are other signs of disease that help to localize the process to the rectal area. These include straining to defecate, the appearance of mucus with the stools, frequent, urgent, scant stools, and blood coating the feces. Signs of discomfort, such as licking, turning suddenly or crying, may also be present.
Rectal polyps, rectal prolapse, intestinal parasites, colonic ulcers, rectal or anal foreign objects and colitis (colonic inflammation), and hemorrhagic gastroenteritis may all present initially with bloody stool or rectal bleeding. Cancer (adenocarcinoma or lymphosarcoma), although uncommon in young dogs, can also cause rectal bleeding.
It is less common for rectal bleeding to be a sign of a systemic bleeding tendency (clotting disorder), but it may occur with rodenticide poisoning or diseases that reduce platelet number or function. Only rarely will rectal bleeding indicate a congenital aberration in clotting mechanisms.
I encourage you to take your dog to your veterinarian for an assessment if this problem is ongoing or recurrent. If she is systemically ill or has any evidence of bleeding tendency elsewhere (blotching, bruising or nasal bleeding), or if the bleeding is continuous or heavy, then she should be seen right away. Otherwise you may wish to arrange a routine appointment.
Your veterinarian will perform a rectal examination and may conduct bloodwork and fecal tests for parasites. Identifying the source of focal bleeding may require colonoscopy or fiberoptic imaging of the colon. These procedures may be available only at referral centers.
Most of the time this is not a life-threatening problem, and the amounts of blood lost are usually small. However, the presence of rectal bleeding or bloody stool in a dog or cat should prompt the pet owner to consult with a veterinarian.
12/04/00
