Fecal Impaction in Dogs

A fecal impaction is a mass of hard stool in the rectum and colon. There may be a predisposing condition, such as an enlarged prostate, that compresses the rectal canal.

Dogs with fecal impactions pass little or no stool despite repeated and forceful straining, are lethargic, have no appetite, experience abdominal distension and vomiting, and may have a hunched-up appearance. Digital rectal examination reveals a large, tubular mass.

Treatment: Veterinary examination and treatment is needed. A severe fecal impaction requires rehydration with intravenous fluids prior to removal. Most will need to be removed under general anesthesia using finger extraction and forceps.

Mild fecal impactions may respond to a combination of an osmotic or stimulant laxative (see Constipation) and a small enema. (Be careful when giving an enema; if done improperly, you could perforate the rectum.) A safe and effective small enema is warm tap water administered at 2.5 to 5.0 ml per pound of body weight. Tap water enemas can be repeated every few hours.

Tap water enemas are given through a rubber catheter connected to a plastic syringe or enema bag. Lubricate the tip of the catheter and insert it 1 to 2 inches (2.5 to 5 cm) into the rectum. Administer the enema. After the enema has been expelled, administer 10 to 20 ml mineral oil (5 to 10 ml for a small dog) into the rectum through the catheter to facilitate passage of the remaining stool.

Packaged saline laxative enemas that contain sodium phosphate (such as Fleet) also are effective for treating constipation and fecal impactions. Phosphate, however, has the potential to cause toxicity in small dogs and dogs with kidney disease, and should not be used in these individuals. Fleet enemas are safe to use in midsize and large dogs with normal kidney function. The recommended dose is one-half unit of a Fleet enema, or one unit of a Fleet Children's enema. Do not repeat. There are special enemas made for pets that are quite safe. Enemas come in plastic bottles equipped with nozzles. Always lubricate the tip of the nozzle before attempting to insert it into your dog's rectum. Insert it far enough into the anal canal to retain the fluid. Squeeze the bottle to administer the enema. Make sure you have help to restrain the dog in case he resists. Most dogs will defecate within a few minutes of receiving an enema.

This article is excerpted from “Dog Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.