Dog Anal Glands: How They Work and When to Act

Scooting across the rug gets treated like a grooming reminder, but for most dogs it signals that two small scent sacs are not emptying the way they should.

Those sacs sit just inside the anus at roughly the 4 and 8 o’clock positions. During a firm bowel movement, rectal muscle presses against them and squeezes out a small amount of strong-smelling fluid. That fluid is normal scent communication, not infection, and VCA Hospitals describes how full sacs, impaction, infection, and abscess form a progression when emptying fails.

The surprising limitation is that routine expression does not fix the underlying mechanics.

Why Some Dogs Struggle While Others Never Do

Soft stools, low-fiber diets, loose body condition, allergies, and anatomy all change how much pressure reaches the sacs. Small and stocky breeds, dogs with chronic soft stool or itchy skin, and dogs with prior impaction tend to refill faster. That pattern is why the Merck Veterinary Manual groups anal sac disease by cause and severity rather than treating every full sac the same way.

Carla noticed this with Lui, her 5-year-old neutered male Cairn Terrier in New York. He scooted twice in one week, licked under his tail in the evening, and left a fishy odor on the couch after passing soft stools for three days. The decision was not whether groomers can express glands, but whether repeated filling pointed to stool quality, itch, or anatomy that needed a vet check.

Firm stool is the support system here.

A well-formed stool presses evenly as it passes. Chronic soft stool removes that pressure, fluid thickens, ducts narrow with irritation, and the next expression becomes harder. In day-to-day practice, vets often see this cycle improve when stool firms up and skin disease is controlled, even without changing the expression schedule.

A Myth Worth Retiring: Every Dog Needs Monthly Expression

Many owners learn that anal glands belong on the same calendar as nail trims. Healthy sacs that empty on their own do not benefit from routine squeezing, and repeated expression can irritate the ducts.

What normal maintenance looks like

No scooting, no licking, no odor beyond the brief smell during defecation, and comfortable posture to sit and defecate. Dogs like Starbuck, a 2-year-old spayed female hound mix, may go through long stretches with no signs at all because firm stools and normal anatomy do the work quietly.

Useful context for normal grooming timing is covered in related guides such as how often to bathe a dog and dog grooming costs, but anal sacs should not be added to that routine by default.

Signs That Deserve Attention Before They Become Painful

Watch for a pattern rather than one scoot after a loose stool.

Early signs to track for 24 to 48 hours

• Scooting more than once in a day or across several days
• Licking or chewing under the tail, straining, or turning sharply to look at the rear
• Fishy odor, redness beside the anus, or crying when sitting
• Chasing the tail paired with soft stool or increased scratching elsewhere

The American Kennel Club outlines similar warning signs and notes that small dogs and dogs with allergies or obesity may need closer monitoring.

Pain changes the timeline.

Swelling beside the anus, a hot red lump, bloody discharge, fever, lethargy, or refusal to defecate can mean impaction, infection, or abscess. That is a same-day veterinary call, not a grooming appointment. Cleaning the ears on a fixed schedule has the same logic problem as expressing glands on schedule; frequency should match the dog, as explained in how often to clean a dog’s ears.

A Practical Sequence You Can Use Today

Start with observation, not intervention.

1. Check stool and comfort. Note stool firmness for two days, scoot count, licking, odor, and any swelling. Firm, segmented stools that hold shape support normal emptying.

2. Do not try to express them at home without training. External squeezing can miss an impacted or infected sac and can injure inflamed tissue. If your vet wants you to learn internal technique for a specific dog, ask for a hands-on demonstration first.

3. Call your vet when signs repeat. Bring the timeline: when scooting started, stool changes, diet changes, itch, weight, and date of the last expression. The exam usually includes rectal palpation of both sacs, assessment of the fluid, and a check for infection, mass, or perianal disease.

4. Ask what would lower recurrence. That may mean fiber adjustment, allergy management, weight management, parasite testing, or treating concurrent skin disease. Dogs with repeated infections sometimes need imaging, flushing under sedation, or referral discussion.

Where I land is preventive and narrow: protect normal emptying with firm stools, healthy weight, and prompt care for itch, and reserve expression for dogs with a demonstrated need. That view would change with controlled evidence that scheduled expression prevents impaction in healthy dogs, but current clinical guidance does not support it.