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Dog Anal Sacs

Veterinarian Reviewed on November 1, 2007 by Dr. Janice Huntingford


Dogs have 2 small anal sacs located on either side of the rectal opening. Ranging in size from a pea to a kidney bean depending on the size of the dog, these small, firm nodules are also known as “scent glands” that allow a dog to mark its territory and identify other canines. The secreted material may be liquid or thick and pasty, and be of grey, brown or black colour. This odorous secretion is used for scent marking or self defence. Contracting the anal sphincter can empty the glands. During urination or defection, a small amount of fluid releases into the urine or coats the stool. If a dog cannot empty these glands voluntarily, then they may become impacted and cause discomfort.

Symptoms and Diagnosis

Small breeds seem to suffer problems with anal sacs, but this condition can affect any dog. Anal gland impaction may have different causes: soft stools, small anal gland openings and overactive anal glands. Very obese dogs may also suffer because their fat skin folds may prevent the draining of the pores. Difficulty in grooming and natural draining are also problems.

If the anal gland is not sufficiently emptied, bacteria may grow and lead to other problems. A dog feeling this discomfort may scoot his rear on the floor or ground to express his glands. Other dogs may lick or chew their perianal area or chase their tails.

Maintaining a good diet plays an important role in the dog’s health. If a low quality pet food contains too much cereal filler, the dog’s stool may be soft and mushy and fail to pressure the anal gland to express the secretion. Higher quality food results in a more firm and compact stool that helps express the glands.

When these sacs give discomfort to the dog, a veterinarian should check these symptoms. The anal glands may require manual expressing. An impacted sac may allow a painful abscess to form and rupture.


One of two methods can help the dog empty its anal sacs: external or internal. For the external method, a warm, moist washcloth is held to the anus. Squeeze both sides of the anal area. Never push so hard that the anal sac ruptures. The exudate will be a liquid to a thick paste. For the internal method, a lubricated glove enters the anus. The thumb and forefinger squeeze one sac with a tissue or rag over the area. Repeat with the remaining sac on the other side. Scootings should stop in about 2 days. Any blood or pus may indicate an infection and require a veterinarian’s attention. Some dogs require several sac emptyings before the sac remains empty. If the sacs enlarge at its 4 o’clock or 8 o’clock position relative the rectum, the veterinarian should also check these symptoms. Antibiotics may treat a ruptured abscess.

If sacs require emptying every few weeks, a specialist or veterinarian experienced with anal sacculectomy may consider permanently removing these sacs.

A non-invasive technique involves a high fiber diet that produces a bulkier stool that can help efficiently squeeze and empty the sac as it passes.

Read also: Dog Adrenal Medulary Tumors
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Our Expert

Dr. Janice Huntingford
Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan

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