How to Express a Dog's Glands Externally: A Guide
Learn how to express a dog's glands externally with this science-backed guide covering anatomy, technique, risks, and when to see your veterinarian.
Quick Answer: Can You Express a Dog's Anal Glands Externally?
Yes, you can express a dog's anal glands externally by applying gentle, firm pressure at the 4 o'clock and 8 o'clock positions around the anus using a gloved hand and a clean cloth or paper towel. However, external expression only empties the outer portion of the gland reservoirs and is best used as a maintenance technique between professional internal expressions performed by your veterinarian or groomer. If your dog is showing signs of impaction, infection, or pain — scooting, excessive licking, foul discharge, or swelling — skip the DIY approach and consult your veterinarian immediately.
The Science of Canine Anal Glands: What They Are and Why Dogs Have Them
Anatomy and Physiological Mechanism
Dogs possess two anal sacs (commonly called anal glands) positioned at approximately the 4 o'clock and 8 o'clock positions relative to the anus. Each sac is a small, pouch-like structure roughly the size of a pea to a small grape (approximately 0.5–1.5 cm in diameter depending on the dog's size), lined with sebaceous and apocrine secretory cells. These cells produce a thick, oily, brownish liquid rich in volatile fatty acids, trimethylamines, and sulfur-containing compounds — the source of the unmistakable odor dog owners recognize.
The sacs connect to the exterior via small ducts that open at the anal sphincter margin. During normal defecation, the passing stool compresses the sacs against the pelvic musculature, forcing a small amount of secretion onto the fecal surface. The internal and external anal sphincter muscles contract rhythmically during this process, providing the mechanical pressure needed for natural emptying. According to the Merck Veterinary Manual, anal sac disease is among the most common conditions affecting the canine perianal region.
Evolutionary Basis: Why Ancestral Canids Developed Anal Glands
Anal sacs are not unique to domestic dogs — they are present across the order Carnivora, including wolves, foxes, bears, and mustelids (skunks being the most famous example). In ancestral wild canids, anal sac secretions served two primary evolutionary functions:
- Territorial scent marking: The secretions contain individual-specific chemical signatures (analogous to a chemical fingerprint) that communicate identity, sex, reproductive status, and social rank to other canids. When a wolf defecates on a raised mound or trail junction, the anal sac coating transforms the feces into a long-lasting olfactory message.
- Defensive secretion: Under acute stress or fear, the anal sphincter involuntarily contracts, forcefully expelling the sacs' contents. In skunks, this mechanism was evolutionarily exaggerated into a primary defense system. In dogs, you may notice this during frightening veterinary visits — a sudden, powerful fishy odor indicates involuntary anal sac expression triggered by sympathetic nervous system activation.
Domestic dogs retain these ancestral mechanisms, but the selective pressures have shifted. Modern dogs often consume softer, lower-fiber diets that fail to provide adequate mechanical compression during defecation, leading to the high prevalence of anal sac retention that makes manual expression necessary.
Why Do Dogs Need Their Glands Expressed? Understanding the Problem
In an ideal scenario, dogs empty their own anal glands naturally every time they defecate. Firm, well-formed stools provide the necessary mechanical pressure against the anal sacs as they pass through the rectum. However, multiple factors disrupt this natural process:
| Factor | Mechanism | Prevalence Impact |
|---|---|---|
| Soft or loose stools | Insufficient mechanical compression of sacs during defecation | Very high — most common contributor |
| Obesity | Perianal fat deposits reduce muscular efficiency of expression | High — correlates with BCS ≥ 7/9 |
| Small breed anatomy | Narrower duct openings and smaller sac volumes fill proportionally faster | Very high in breeds under 25 lb (11 kg) |
| Chronic diarrhea / GI disease | Persistent soft stool eliminates natural emptying entirely | Moderate — secondary to underlying condition |
| Duct obstruction or stenosis | Scar tissue, thickened secretions, or anatomical narrowing block outflow | Low — requires veterinary intervention |
| Hypothyroidism | Reduced smooth muscle tone and altered sebaceous secretion | Low — comorbidity factor |
When anal sacs fail to empty, secretions accumulate, thicken, and can become impacted. The progression typically follows this clinical sequence:
- Sac retention — normal secretions accumulate beyond typical volume (days to weeks)
- Impaction — secretions thicken to a paste-like consistency, cannot flow through ducts
- Sacculitis — inflammation and bacterial overgrowth within the sac lining
- Abscess formation — infection progresses, sac wall weakens and may rupture through the skin
A 2021 retrospective study published in the Journal of Small Animal Practice found that anal sac disease affects approximately 12.5% of dogs presented to general veterinary practices, with smaller breeds and overweight dogs showing significantly higher incidence rates.
How to Express a Dog's Glands Externally: Step-by-Step Technique
External expression is a technique that applies pressure from outside the body to compress the anal sacs and expel their contents. It is less thorough than internal expression (where a gloved finger is inserted into the rectum to compress each sac individually against an external thumb), but it avoids rectal penetration and is suitable for routine maintenance when the sacs are not impacted.
What You Will Need
- Disposable nitrile gloves (latex-free to avoid allergy risk)
- Paper towels or clean washcloths (multiple — this gets messy)
- Pet-safe wipes for cleanup
- A helper to gently restrain and comfort your dog (strongly recommended)
- A washable surface or old towel to protect flooring
- Treats for positive reinforcement after the procedure
The External Expression Procedure
Step 1 — Position your dog. Have your helper stand beside the dog, offering treats and gentle reassurance. Position the dog standing on a non-slip surface. For small dogs (under 20 lb / 9 kg), you may place them on a stable table with a non-slip mat. For larger dogs, kneeling behind them works well.
Step 2 — Prepare the area. Put on gloves. Fold a paper towel or washcloth and hold it ready near the anal area. The secretion will be expelled with surprising force in some dogs — having the cloth positioned before you begin prevents the material from spraying onto walls, floors, or your clothing.
Step 3 — Locate the glands. Visually identify the anus. The anal sacs sit beneath the skin at approximately the 4 o'clock and 8 o'clock positions. In most dogs, you can feel them as small, firm, grape-like structures just lateral to the anal opening. If the sacs are very full, they may be visibly bulging.
Step 4 — Apply pressure. Place the folded paper towel over the anal area. Using your thumb and index finger of the same hand (or two hands for larger dogs), position your digits at the 4 o'clock and 8 o'clock positions, approximately 1 cm outside the anal margin. Apply firm, steady pressure directed inward and slightly upward, compressing the sacs between your fingers. Think of squeezing a toothpaste tube from the base toward the opening.
Step 5 — Release and assess. Hold pressure for 5–10 seconds, then release. You should see brownish, oily fluid on the paper towel. The consistency ranges from thin liquid (normal) to thick paste (early impaction). If no material is released after 2–3 attempts, the ducts may be obstructed, or the sacs may require internal expression by a professional.
Step 6 — Clean up and reward. Wipe the perianal area clean with pet-safe wipes. Remove gloves and dispose of all materials. Immediately reward your dog with high-value treats and praise to create a positive association with the handling. This is critical — dogs who develop negative associations with perianal handling may become defensively reactive during future attempts.
⚠️ Important Safety Warnings
- Never apply excessive force. Anal sac tissue is delicate. Aggressive squeezing can rupture the sac wall internally, causing cellulitis or abscess formation requiring surgical intervention.
- Stop immediately if your dog shows pain. Whimpering, snapping, tensing, or trying to escape are signals to cease. Pain during expression often indicates sacculitis or abscess — conditions requiring veterinary treatment, not home management.
- Do not attempt external expression if you observe swelling, redness, open sores, or bloody discharge near the anus. These are signs of advanced disease that require prompt veterinary care.
- Frequency matters. Expressing glands too frequently (more than every 4–6 weeks without veterinary recommendation) can cause the sac walls to lose muscular tone, creating a dependency cycle where the dog loses the ability to self-empty.
External vs. Internal Expression: Understanding the Difference
| Criteria | External Expression | Internal Expression |
|---|---|---|
| Technique | Compression from outside the body using fingers on perianal skin | Gloved finger inserted into rectum; each sac compressed individually against external thumb |
| Thoroughness | Partial — empties accessible portion of sac, may leave residual material | Complete — allows direct compression of entire sac and assessment of contents |
| Diagnostic value | Low — cannot assess sac wall texture, duct patency, or secretion quality fully | High — practitioner can palpate for masses, assess wall thickness, evaluate secretion consistency |
| Appropriate for | Routine maintenance on dogs with mild retention; between professional visits | Impacted sacs, diagnostic evaluation, dogs with recurrent anal sac disease |
| Who should perform | Trained owners, groomers | Veterinarians, veterinary technicians, experienced groomers |
| Typical cost (2026) | $0 (DIY) or $15–$30 at groomer | $25–$65 at veterinary clinic (standalone visit); often bundled with exam |
| Risk of complication | Low when done gently; higher with excessive force | Very low when performed by trained professional |
Breed Variations: Which Dogs Are Most Prone to Anal Gland Issues?
While any dog can develop anal sac problems, breed and body size significantly influence risk. Research published in Veterinary Record identified several breeds with statistically elevated rates of anal sac disease:
- Chihuahuas — highest reported incidence among purebreds; small duct diameter and frequent soft-stool issues contribute
- Toy and Miniature Poodles — anatomical predisposition combined with common dietary sensitivities
- Cocker Spaniels — overrepresented in anal sac disease cases; prone to sebaceous gland disorders generally
- Lhasa Apsos and Shih Tzus — brachycephalic small breeds with higher GI sensitivity rates
- Basset Hounds and Beagles — medium breeds with higher-than-expected incidence, possibly related to body conformation and weight management challenges
Large and giant breeds (Great Danes, German Shepherds, Labrador Retrievers) experience anal sac disease at lower rates, partly because their larger stool volume provides more effective natural compression. However, German Shepherds are overrepresented in perianal fistula cases — a separate but anatomically related condition that should not be confused with simple anal sac impaction.
Common Misconceptions About Anal Gland Expression
| Myth | Fact |
|---|---|
| "All dogs need their glands expressed regularly." | False. Most dogs self-empty without issue. Routine expression of healthy glands can actually weaken the sac's natural contractile ability and create iatrogenic (human-caused) dependency. Only express when clinical signs indicate retention. |
| "Scooting always means full anal glands." | False. Scooting (dragging the rear along the floor) can also indicate intestinal parasites (especially tapeworms), perianal dermatitis, allergies, or perianal tumors. Always rule out parasites with a fecal flotation test before assuming anal sac issues. |
| "Adding fiber to the diet will fix anal gland problems." | Partially true. Increasing dietary fiber (e.g., adding 1–2 teaspoons of canned pumpkin per 10 lb of body weight, or switching to a higher-fiber kibble) can firm stools and improve natural expression. However, fiber does not resolve existing impactions, infections, or anatomical duct obstructions. |
| "If I express them myself, I never need to see a vet." | Dangerous myth. External expression cannot diagnose or treat sacculitis, abscesses, anal sac adenocarcinoma, or perianal fistulas. Dogs with recurrent issues (more than 3–4 episodes per year) need veterinary evaluation to rule out underlying conditions and discuss long-term management, including surgical sacculectomy if warranted. |
| "Anal gland fluid is supposed to smell terrible." | Partially true. Normal anal sac fluid has a strong, fishy, metallic odor. However, a putrid, rotting, or pus-like smell indicates infection and requires veterinary attention. Blood-tinged fluid is also abnormal. |
When Anal Gland Behavior Signals a Problem
🚨 When to Call Your Veterinarian
Contact your veterinarian promptly if you observe any of the following:
- A visible swelling, lump, or bulge beside the anus (possible abscess)
- Bloody or pus-like discharge from the anal area
- An open wound or draining tract near the anus (ruptured abscess)
- Your dog is in obvious pain when sitting, defecating, or when the tail base is touched
- Fever, lethargy, or loss of appetite accompanying scooting or licking behavior
- Repeated anal sac issues (more than 3 episodes in 12 months)
- Any anal gland expression that yields material that is bloody, black, chunky, or foul beyond the normal fishy odor
Anal sac abscesses that rupture through the skin require veterinary wound management, systemic antibiotics, and sometimes surgical debridement. Do not attempt to treat a ruptured abscess at home.
Anal Sac Adenocarcinoma: A Rare but Serious Concern
Anal sac adenocarcinoma (apocrine gland anal sac adenocarcinoma, or AGASACA) is a malignant tumor arising from the anal sac glandular tissue. It accounts for approximately 17% of perianal tumors in dogs and is particularly prevalent in Spaniels, Dachshunds, and German Shepherds, according to AKC health resources. This cancer often produces paraneoplastic hypercalcemia (elevated blood calcium), which causes increased thirst, urination, and vomiting. Any firm, non-painful mass detected near the anal sac during expression should prompt immediate veterinary biopsy and staging.
Practical Implications: Prevention and Daily Life Management
Evidence-Based Prevention Strategies
1. Optimize stool quality through diet. Feed an AAFCO-approved diet that produces firm, well-formed stools. For dogs prone to soft stools, consider adding a soluble fiber supplement such as psyllium husk (start with ¼ teaspoon per 10 lb / 4.5 kg body weight daily, mixed into food, and titrate up as needed). Canned pumpkin (plain, not pie filling) at 1–2 teaspoons per 10 lb body weight is a commonly recommended alternative.
2. Maintain healthy body weight. Dogs with a Body Condition Score (BCS) of 6/9 or higher have significantly more difficulty self-expressing anal glands due to perianal fat deposits. Work with your veterinarian to develop a weight management plan if your dog is overweight. Target weight loss of 1–2% of body weight per week is safe and sustainable.
3. Ensure adequate exercise. Regular physical activity promotes healthy GI motility and firmer stools. Aim for breed-appropriate exercise minimums — typically 30–60 minutes of moderate activity daily for most breeds.
4. Address underlying GI conditions. Chronic soft stools caused by food sensitivities, inflammatory bowel disease (IBD), exocrine pancreatic insufficiency (EPI), or parasitic infections must be treated at the root cause. Recurrent anal sac retention is often a symptom of a broader GI issue.
5. Schedule regular veterinary wellness exams. During routine physical examinations, your veterinarian will typically palpate the anal sacs and express them if they are overfull. This provides professional monitoring without the need for owner-initiated expression in most cases.
6. Avoid unnecessary expression. If your dog has no clinical signs of anal sac retention (no scooting, no odor, no licking), do not express the glands. Unnecessary manipulation can cause inflammation and create a cycle of dependency.
Cost Expectations for Anal Gland Care (2026 Pricing)
| Service | Typical Cost Range | Notes |
|---|---|---|
| Groomer external expression | $15–$30 | Often included in full grooming packages |
| Veterinary expression (standalone) | $25–$65 | May include brief exam; varies by region |
| Anal sac flush/lavage | $75–$150 | For impacted or infected sacs; may require sedation |
| Abscess treatment (lancing, antibiotics) | $150–$400 | Includes exam, procedure, and medications |
| Surgical sacculectomy (bilateral) | $800–$2,500 | For chronic, recurrent disease; specialist referral may increase cost |
How Is Anal Gland Function Different in Dogs vs. Humans?
Humans possess anal glands, but they are rudimentary and largely non-functional compared to those of dogs. Human anal glands are scattered, small mucous-secreting structures located in the anal canal mucosa. They do not form organized sac-like reservoirs, do not produce species-specific scent markers, and do not require manual expression. The human equivalent of anal sac disease is an anal fistula or perianal abscess, which arises from obstruction of the anal crypt glands — anatomically related but functionally distinct structures.
The key physiological difference is that canine anal sacs are dedicated scent communication organs with a defined reservoir-and-duct anatomy, while human anal glands are vestigial mucous secretors with no known communication function. This evolutionary divergence reflects the far greater reliance of canids on olfactory signaling in social and territorial behavior.
Related Behaviors and Cross-References
Understanding anal gland function connects to several other canine behaviors and health topics:
- Scooting and dragging: Often the first visible sign of anal sac retention, but also associated with tapeworm segments (Dipylidium caninum) causing perianal irritation. A fecal exam differentiates these causes.
- Tail-base licking and chewing: Dogs may over-groom the perianal region when glands are full. This behavior can also indicate flea allergy dermatitis, which concentrates reactions at the tail base.
- Fear-based anal sac release: Involuntary expression during stressful events (vet visits, thunderstorms, nail trims) is a normal sympathetic nervous system response. This is not a sign of disease — it is the ancestral fear-defense mechanism in action.
- Scent-marking behavior: Dogs who raise their leg to urinate or defecate on elevated surfaces are engaging in scent-marking behaviors that evolutionarily relied on anal sac secretions for chemical communication. Intact males typically engage in more frequent marking than neutered males or females.
- Dietary fiber and GI health: The connection between stool quality and anal gland function makes fiber management a cornerstone of prevention. See our guides on high-fiber dog foods and pumpkin for dogs for detailed supplementation guidance.
Frequently Asked Questions
Is it normal for my dog's anal glands to need expression every month?
Monthly expression is more frequent than average and may indicate an underlying issue such as chronic soft stools, obesity, or breed predisposition. While some individual dogs genuinely require this frequency, it warrants a veterinary evaluation to identify and address the root cause rather than simply managing the symptom indefinitely. Dogs needing expression more often than every 6–8 weeks should be assessed for dietary modification, weight management, or underlying GI disease.
Can I damage my dog's anal glands by expressing them incorrectly?
Yes. Excessive force during external expression can cause bruising of the sac wall, rupture of the sac internally (leading to cellulitis), or trauma to the anal sphincter muscles. Internal expression performed without proper technique carries additional risks including rectal mucosal damage. If you are unsure of your technique, ask your veterinarian or a veterinary technician to demonstrate the correct procedure on your dog during a clinic visit. Most practices will do this for a brief tech-visit fee ($25–$45).
What does it mean when my dog's anal gland fluid is green or contains blood?
Green-tinged or bloody anal gland discharge is abnormal and indicates infection (sacculitis), abscess formation, or potentially neoplasia. Normal anal sac fluid ranges from yellowish-brown to dark brown and may be thin or paste-like. Any color outside this range — green, red, black, or gray — warrants prompt veterinary evaluation. Your veterinarian will likely perform cytology on the discharge to identify bacteria, inflammatory cells, or abnormal cells.
Does feeding my dog raw food prevent anal gland problems?
There is no peer-reviewed evidence that raw diets specifically prevent anal sac disease. The mechanism of prevention is stool firmness, not diet type. Some dogs produce firmer stools on raw diets (due to high protein and low carbohydrate content), while others experience softer stools from the high fat content or bacterial load. If your dog produces firm, well-formed stools on their current diet — whether raw, kibble, or home-cooked — the natural expression mechanism should function adequately.
How is this different from what groomers do?
Most groomers perform external expression only, which is appropriate for routine maintenance. Veterinary professionals typically perform internal expression, which is more thorough and allows diagnostic assessment of the sac contents and walls. For dogs with recurrent issues, veterinary internal expression is preferred because the practitioner can identify early signs of impaction, infection, or abnormal growths that external expression cannot reveal.
My dog's glands were just expressed a week ago and they're scooting again — what's wrong?
Rapid refilling (within 1–2 weeks) suggests either incomplete emptying during the previous expression, ongoing soft stool production, or an inflammatory process causing increased secretion. This pattern warrants veterinary investigation rather than repeated home expression. Your veterinarian may recommend anal sac flush under sedation, dietary modification, or in severe recurrent cases, bilateral sacculectomy (surgical removal of both anal sacs).
Aaron Whyte
All our authors care for dogs every day — read more of their work on the authors page.
