Dog Anal Glands: Signs, Expression, and Vet Care

Dogs do need their anal glands in one sense and not in another. The two small scent sacs just inside the anus are normal, functional anatomy that every dog is born with, yet plenty of dogs live a full life without ever having them manually emptied, and some have them surgically removed for medical reasons. If your dog is scooting, licking at the rear, bleeding near the anus, or has a hot painful swelling beside the opening, book a veterinary appointment rather than watching and waiting, because an impacted sac can turn into an abscess in a short span of time.

The rest of this page covers what the glands actually do, the warning signs worth acting on, who should empty them and how that is done, what it tends to cost, and the point at which a vet starts discussing surgery.

What anal sacs are and why dogs have them

The anal sacs sit just under the skin on either side of the anus, roughly at the four o'clock and eight o'clock positions, each with a narrow duct opening just inside the anal margin. They are lined with glandular tissue that produces an oily, brownish or greyish fluid with a sharp, fishy, metallic odour that most owners recognise instantly once they have smelled it on bedding or a sofa cushion.

The purpose is communication. That fluid carries a scent signature unique to the individual dog, deposited in tiny amounts onto the stool during a normal bowel movement, which is part of why dogs are so interested in each other's rear ends and in other dogs' droppings on a walk. The sacs can also empty suddenly under fear or stress, which is why a frightened dog at the vet clinic sometimes leaves a very distinctive smell behind. Anatomically they are cousins of the scent glands skunks use defensively, scaled down and far less dramatic.

So when people search for why dogs get anal glands, there are two fair answers. Dogs have them because scent marking is a core part of canine social signalling. Dogs get anal gland problems because those narrow ducts are easy to block, and because the system depends on firm stool pressing the sacs empty from the inside.

The signs that something is wrong

Healthy anal sacs are invisible to the owner. Problems announce themselves, usually in one of a few ways.

Sign	What it often points to	How quickly to act
Scooting the bottom along carpet or grass	Full, irritated or inflamed sacs, though worms and itchy skin can cause the same behaviour	Appointment in the next few days
Constant licking or chewing at the base of the tail or under the tail	Irritation, inflammation or early infection	Appointment soon
A sudden fishy or metallic smell on bedding, laps or furniture	A sac releasing on its own, sometimes from stress	Not urgent alone, but note how often it happens
A firm, hot, red swelling to one side of the anus	Impaction or a developing abscess	Same day
Blood or pus draining near the anus, or an open hole in the skin	A ruptured abscess or an infected sac	Same day
Crying when sitting, tense posture, reluctance to poo, tail held oddly	Pain in the anal sac region	Same day
A lump near the anus that does not settle within days	Needs assessment, and only a sample can say what it is	Prompt appointment

Blood, pus, a visible swelling beside the anus, or a dog who cannot settle or sit is a same-day veterinary problem, not something to monitor over a weekend.

Two extra points deserve emphasis. First, any new lump near the anus should be checked by a vet, and only a needle sample or biopsy can tell you what it is; appearance alone cannot. Anal sac tumours do occur, and one of their quieter clues is a dog who suddenly starts drinking and urinating far more than usual, because some of these tumours raise blood calcium. Second, scooting is not proof of anal sac disease. Tapeworm segments, food or environmental allergies, and plain perianal skin irritation all produce the same scooting, which is exactly why a diagnosis matters more than a guess.

Why some dogs need expression and others never do

In a dog whose system works normally, nothing needs to be done. Each formed stool presses the sacs as it passes, the ducts open, the fluid goes out with the stool, and the owner never thinks about it. Routine emptying of healthy sacs is not a maintenance task most dogs require.

Problems cluster around anything that breaks that mechanism:

• Chronically soft stool or diarrhoea. Loose stool does not generate the pressure needed to empty the sacs, so material sits and thickens.
• Low dietary fibre or an abrupt diet change that leaves stool consistently soft.
• Excess body weight, which changes the tissue around the sacs and the way the sphincter works.
• Allergic skin disease. Inflammation around the duct openings can narrow or block them, and vets commonly see anal sac flare-ups in dogs who are itchy elsewhere.
• Thick or sludgy secretion that cannot pass through a narrow duct.
• Previous infections or abscesses, which can scar a duct and make repeat episodes more likely.
• Individual anatomy and conformation, including duct angle and sac position. Smaller breeds are presented for anal sac trouble often, although any size of dog can be affected.

General underlying illness, including hormonal conditions that affect skin quality, can play a part too. This is why a dog who needs emptying every few weeks deserves an investigation into the cause rather than an endless cycle of appointments. Results vary from dog to dog: some respond well to a diet adjustment and weight loss, others have a structural issue that no amount of fibre will fix. Talk to your vet about which category your dog is in before committing to a long-term routine.

Who should empty them, and what aftercare looks like

Expression is done one of two ways. External expression involves pressure applied to the outside of the sacs through the skin, which works for mildly full sacs. Internal expression, performed with a gloved finger in the rectum so that each sac is isolated and emptied individually, is more thorough and is what a vet or veterinary nurse will usually do when a sac is genuinely impacted.

This is a job for a veterinary professional, or for a groomer trained and willing to do it. It is not a home task. The tissue is delicate, the sacs are easy to bruise, and clumsy pressure on an already inflamed sac can rupture it or drive infection deeper into surrounding tissue. An over-enthusiastic routine on healthy sacs can also create the very irritation it was meant to prevent, so many vets advise against expressing a dog who has no symptoms at all.

Cleaning, in the anal gland context, means aftercare rather than prevention. If a sac has ruptured or been lanced, your vet will give specific instructions, which typically involve keeping the area clean, warm compresses, a prescribed topical or oral medication, and a cone so the dog cannot lick the wound open. Do not apply human antiseptics, essential oils or disinfectants to the area without asking first; several are irritating or toxic to dogs. Day to day, a quick wipe of the perianal area with a plain dog-safe wipe after a soft stool is reasonable hygiene, nothing more.

What expression usually costs

Costs vary widely by clinic, region and what else is going on, so treat any figure you read online as a rough signal rather than a quote. The pattern, though, is consistent.

The cheapest version is expression added to a grooming appointment, where it is often a small add-on to the bill. Next up is a nurse or technician appointment at a veterinary practice, priced as a short routine visit. A full vet consultation costs more because you are paying for the examination and diagnosis as well as the procedure, and that is the right choice when there is pain, swelling, blood or a repeat problem.

From there, prices rise with complexity. An infected or impacted sac may need sedation, flushing, infusion of a medicated preparation, antibiotics and pain relief. An abscess that has ruptured needs wound care and follow-up. Surgical removal is the most expensive option by a wide margin, since it involves general anaesthesia, a surgeon's time and post-operative monitoring. Ask your practice for a written estimate before anything beyond a routine emptying.

Impaction, infection, and when removal comes up

The usual progression runs from full, to impacted, to infected, to abscessed. An abscess shows as a painful swelling beside the anus that may burst through the skin and drain blood-tinged pus, which is both alarming and genuinely painful for the dog. Treatment is a veterinary job: the sac is usually flushed under sedation, infection is treated, pain is managed, and the wound is monitored while it closes.

Removal of the anal sacs, called anal sacculectomy, is the option vets raise for dogs with repeated impactions or abscesses that have not responded to medical management and cause changes, and for confirmed anal sac tumours. It is effective at ending the problem, but it is not a casual procedure. The external anal sphincter wraps closely around the sacs, so the recognised risks include faecal incontinence, scarring or narrowing of the anal opening, and wound breakdown in a region that is difficult to keep clean. For that reason it is generally reserved for dogs who truly need it and is best performed by a surgeon experienced with the anatomy. Weigh it as a considered decision with your vet, not a quick fix for occasional scooting.

Key takeaways

• Anal sacs are normal scent-marking anatomy, and most dogs empty them naturally with every firm stool.
• Routine expression is not required for a dog with no symptoms, and unnecessary handling can cause irritation.
• Scooting, rear-end licking and a sudden fishy smell warrant a vet check, partly to rule out parasites and allergies.
• Swelling, bleeding, pus, or obvious pain near the anus is a same-day veterinary issue.
• Any persistent lump near the anus needs veterinary assessment, and only a sample can identify it.
• Expression belongs to a vet, a veterinary nurse or a trained groomer, never to a DIY attempt at home.
• Recurring problems deserve a search for the underlying cause, commonly stool consistency, body weight or allergic skin disease.
• Surgical removal is a real option for recurrent or tumour cases, with genuine risks that are worth discussing in detail.

If your dog keeps coming back to the same problem, the most useful thing you can do is stop treating each episode as an isolated event and ask why it keeps happening. Your veterinarian owns the diagnosis and the treatment plan here: the physical examination, the decision about whether the issue is an impaction, an infection, a skin disease or something else entirely, and the choice of what to do about it. Everything an owner does at home, from diet and weight management to keeping the area clean after a rupture, works inside the space that proper veterinary care creates.

For a wider view of which canine symptoms cannot wait until morning, see Dog Emergency Signs.