Unveiling the Mystery of Cat Anal Glands: What Every Cat Owner Should Know
A veterinarian explains cat anal glands: where the sacs sit, why a cat's rear smells fishy or cheesy, how impaction, infection, abscess, and rupture look, why expression is a vet job, and how to prevent problems.
BVMS, MRCVS
An owner gently lifting the tail of a tortoiseshell cat standing on a towel-covered table at home.
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Cat anal glands are two pea-sized scent pouches just inside the anus, and most owners never think about them until a fishy smell turns up on the sofa or a cat starts scooting. They cause far fewer problems in cats than in dogs, but a blocked, infected, or burst sac is painful and needs a veterinarian, not a home squeeze. Here is what the sacs do, how to tell whether the smell is really them, what goes wrong, and how it is treated and prevented.
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What Are Cat Anal Glands and Where Are They?
Cat anal glands, properly called anal sacs, are two pea-sized pouches on either side of the anus at the four o'clock and eight o'clock positions. Each makes a strong-smelling, oily secretion and drains through a tiny duct just inside the anal ring. The sacs empty during a normal bowel movement, when the anal muscles squeeze a little secretion onto the stool as a scent stamp.
- 1Cat anal sacs sit at the four o'clock and eight o'clock positions beside the anus
- 2A fishy or cheesy smell usually means a sac has leaked or is overfull
- 3Impaction is the most common problem in cats, though far rarer than in dogs
- 4Do not squeeze the sacs at home; if your cat scoots, licks, or swells by the anus, see your veterinarian
Both sexes have them from kittenhood, so female cats have them too. A healthy cat butt shows no bulge, discharge, or lingering smell, because the cat anal gland secretion leaves on the stool; a cat with full anal glands may leak a few drops when startled or relaxed. The Merck Veterinary Manual calls anal sac disease common in dogs but infrequent in cats.
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Anal Sacs vs. Other Cat Scent Glands
Cat scent glands are not limited to the rear. Cats carry scent glands on the cheeks, chin, forehead, paw pads, and tail base, and cheek-rubbing your leg or scratching a post leaves scent from those skin glands. The anal sacs, the cat butt glands owners actually smell, differ in three ways:
- They are pouches, not skin glands. They store secretion and release it in a pulse, mainly onto the stool.
- The smell is far stronger. Cheek scent is barely detectable to people; anal sac secretion is the fishy, musky odor you notice across a room.
- They are the ones that get blocked. Facial and paw glands almost never cause medical problems.
Why do cats release their glands, and why do cats sniff butts? Cats read anal sac scent from each other, and a frightened cat may fire the sacs involuntarily: the sudden fishy waft in the carrier on the way to the vet.
Why Does My Cat's Butt Smell?
When a cat's butt smells, start with the smell itself. Anal sac secretion is fishy, sometimes cheesy or metallic, and strongest right at the rear, a fishy smell near the tail base rather than over the whole cat. A cat that smells like fish after leaving your lap has likely leaked a little sac fluid, and a cheesy smell on the bum usually comes from the same dried secretion. One leak is not an emergency; a rear that smells constantly while the cat also scoots or licks points to a sac that is not emptying. Male or female, the answer is the same, even when a tom smells more musky. The table below separates anal sac odor from urine, stool, dental, and skin causes, with a next action for each. If your cat stinks suddenly, or you notice the cat leaking smelly fluid onto bedding, the anal sacs are the first place to look.
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| Smell | Likely source | Next action |
|---|---|---|
| Fishy odor (musky or metallic), strongest at the rear | Anal sacs: a normal leak when startled, or an overfull or impacted sac | One-off leak: wipe and watch. Repeats, scooting, or licking: book a vet exam |
| Cheesy or sour at the rear, sometimes with a moist patch | Dried anal sac secretion on the fur, or an early sac infection | Check for swelling beside the anus; vet within a few days if it persists |
| Rotten or foul with sticky, bloody, or pus-like discharge | Ruptured anal sac abscess or infected wound | Same-day veterinary visit |
| Poop-like, with dirty fur under the tail | Soft stool, diarrhea, or a long-haired cat that cannot clean itself | Trim and clean the fur; vet if the stool stays soft beyond two days |
| Ammonia or strong urine smell | Urinary tract infection, urine scald, or litter box avoidance | Vet within 24 hours, sooner if the cat strains |
| Bad breath rather than a rear-end smell | Dental disease or, less often, kidney disease | Book a dental and general check; not an anal gland problem |
Cats do empty their own glands, and fear or excitement can release the sacs suddenly. That is why a startled cat sometimes leaves a fishy spot on your lap, which is normal if rare. A kitten whose butt smells like poop is usually hygiene: soft stool sticking to the fur, fixed by a stool check and a gentle clean.
Owners who ask "why does my cat express his glands on me?" are usually dealing with fear: a scared cat, whether picked up suddenly, carried into a vet visit, or startled by a loud noise, can express its glands right onto your lap. Some cats also release a little when they are very happy, especially while kneading on a lap. That cheese-like smell afterward is the anal sac fluid itself, not a sign of a diet problem.
Signs of Anal Gland Problems in Cats
A cat that drags its bum across the floor or wipes it on the carpet is telling you something is uncomfortable back there. To tell whether a cat needs its glands expressed, look for a cluster of signs:
- Scooting: dragging the bottom along the floor or rubbing it on the carpet, the classic anal scooting in cats
- Licking or biting at the anus or tail base, sometimes leaving a patch of chewed fur
- A fishy or cheesy smell that lingers where the cat sits
- Swelling or redness beside the anus at the four or eight o'clock position
- Straining, crying, or reluctance to pass stool
- Discharge: brown, bloody, or pus-like fluid on the fur or bedding
One sign seen once can mean a sac emptied on its own; scooting that repeats over several days, or any swelling or discharge, means it has not. Scooting is not always a gland problem either: tapeworm, fleas, food allergy, and stool stuck in the fur cause the same behavior.
Impaction, Infection, Abscess, and Rupture in Cats
Most cat butt problems owners notice, from scooting to a swollen spot beside the anus, trace back to one of these stages. Anal sac disease in cats moves through four separate stages, impaction, infection, abscess, and rupture, each with its own signs, and the stage tells you how urgent the visit is. Owners typically notice scooting, a swollen or red spot beside the anus, or constant licking. Impaction, infection, abscess, and rupture are stages of one problem, and each carries different risks of recurrence and of eventually needing the sacs removed. Owners often describe the first stage as the cat's scent glands being clogged, and that is the same thing as impaction.
Owners describe the discharge in several ways, and each points to a stage. White stuff coming out of a kitten's bum, or white liquid from a cat's bum, is usually thick, pale sac secretion from an overfull or impacted sac, though in a kitten it can also be tapeworm segments, so check the stool. Smelly liquid from a cat's bum that is brown or grey and oily is ordinary secretion leaking under pressure. Clear liquid coming out of a cat's bum, or thin yellow fluid, suggests the sac is inflamed, and any bloody or pus-like fluid means abscess or rupture.
Impaction
Impaction is the most common form of anal sac disease in cats, according to the Merck Veterinary Manual, and much less common than in dogs. The duct blocks and the contents thicken into a paste. A cat with impacted anal glands scoots, licks, and smells stronger than usual, with little or no swelling yet.
Infection
If impacted material sits long enough, bacteria multiply and the sac inflames. The cat becomes sore and licks constantly, and the cat anal gland discharge turns thin, yellow, or blood-tinged. A cat anal gland infection still responds well to expression, flushing, and antibiotics.
Abscess
An infected sac can fill with pus and become a hot, painful lump. A cat anal gland abscess shows as swollen anal glands at the four or eight o'clock position, often with fever, lost appetite, and hiding. Do not wait for it to settle.
Rupture
When pressure builds enough, the abscess bursts. Cat anal gland rupture looks like a small open wound beside the anus draining foul, bloody, or pus-like fluid, and the cat often seems suddenly more comfortable. It still needs the vet to clean the wound, flush the sac, and prescribe antibiotics and pain relief. Petful's guide to abscesses in cats covers wound aftercare.
Anal gland cancer in cats
Anal sac adenocarcinoma is uncommon, but VCA Animal Hospitals notes that older cats can develop it and that the signs mimic an infection: swelling beside the anus, dragging the back end, and excessive licking. A swelling in a senior cat that does not resolve or keeps returning should be sampled.
Do Cats Need Their Anal Glands Expressed?
Most cats never do. PetMD's veterinary guidance is direct: healthy cats without anal gland abnormalities should not need their glands manually squeezed. So do cats need their anal glands expressed on a schedule? No. Expression treats a sac that has stopped emptying, and the signs that a cat needs its anal glands expressed are the ones above: repeated scooting, persistent licking, a lingering fishy smell, or swelling.
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Vets do differ on one point. Some express the sacs at routine visits for a cat with a history of impaction, reasoning that catching an early blockage prevents infection. Others leave healthy sacs alone, because scar tissue from repeated squeezing can narrow the duct and invite the next blockage. Both positions are reasonable, so how often your cat's glands need expressing is a schedule your veterinarian sets for your individual cat.
Should You Express a Cat's Anal Glands at Home?
Usually no. Leave expression to your veterinarian. Cats are hard to restrain safely, a full sac is painful to press, and an infected sac can burst under pressure. Expressing cat anal glands correctly also means recognizing normal secretion and stopping if the fluid is bloody or purulent.
- Pressing an inflamed or abscessed anal sac at home can rupture the sac and spread infection into the tissue around the anus. If your cat cries, swells beside the anus, or leaks bloody or pus-like fluid, stop and ask your veterinarian to examine the sac instead.
What the vet does is brief. For cat anal gland expression the veterinarian places a gloved finger inside the rectum, locates the sac between finger and thumb, and presses gently to empty it into a gauze swab. External expression, pressing from outside only, suits a mildly full sac but empties it less completely, and cleaning cats' anal glands that are impacted may need flushing under mild sedation.
If you think your cat needs its glands expressed, look for the signs above and let the clinic confirm it. If your veterinarian has confirmed the sacs are healthy but slow to empty and has shown you how, home expression can be part of a plan. Owners who want the technique should read Petful's vet-written guide on how to express anal glands step by step, written for dogs with a cat section, and decide with their vet. Without that guidance, do not attempt it.
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When to See a Vet and How Treatment Works
Book an appointment if scooting or licking lasts more than a couple of days, the smell will not clear, or you can see or feel swelling beside the anus. Some signs mean today. For a second veterinary walkthrough of signs, causes and treatment, see WebVet's cat anal glands guide.
- Blood or pus draining beside the anus, a hot or rapidly growing swelling, straining to pass stool with nothing produced, fever, refusing food, or unusual lethargy. These point to an abscess or rupture, and waiting risks a deeper infection.
Diagnosis
The vet confirms the problem by rectal palpation: a gloved finger feels whether each sac is full, thickened, or painful, and expresses it at the same time. Because scooting and licking have other causes, the vet also rules out parasites, allergies, and skin disease, and may sample a firm or recurring lump in an older cat to rule out adenocarcinoma. The vet checks the sacs by feel and rules out the other causes of scooting: worms, fleas, allergies, and skin infection.
Treatment
- Impaction: manual expression, with flushing if the material has solidified
- Infection: expression and flushing, then antibiotic and anti-inflammatory medication, often infused into the sac
- Abscess: lanced, drained, and flushed, then antibiotics and pain relief
- Rupture: the vet cleans and flushes the wound, then antibiotics and pain relief while it heals from the inside out
Aftercare at home
There are no safe home remedies for a cat's swollen anus beyond what the vet prescribes, but aftercare matters. VCA advises warm compresses for pain relief (Merck: 15 to 20 minutes every 8 to 12 hours on an abscess), and a cone collar stops the licking that makes a treated sac flare again. A soft cone such as the SunGrow post-surgery recovery collar is usually tolerated better than rigid plastic.
Scooting after expression is normal for a day because the area is tender; a cat in pain after glands expressed that is not settling within a few days, or a cat still leaking after glands expressed, needs a recheck. At home, use warm compresses and the cone if one was sent home, and watch for those recheck signs.
Surgical removal
Recurrence is the trigger for surgery: for repeated impactions or abscesses, or a tumor, the vet may recommend anal sacculectomy. You can remove a cat's scent glands and the cat lives normally, but the surgery sits close to the nerves controlling the anus. Merck lists fecal incontinence as a common complication when the caudal rectal branch of the pudendal nerve is damaged; VCA notes it is usually temporary, resolving within days to weeks, and rarely permanent.
How Much Does It Cost to Express Cat Glands?
PetMD's reported range starts at about 35 dollars for a simple expression, on top of the exam fee, and rises with flushing, medication infused into the sac, sedation, or antibiotics. Treating an abscess costs considerably more once lancing under sedation, wound care, and rechecks are involved, and a sacculectomy is a surgical bill in its own right. These are reported ranges; prices vary widely by region and clinic, so ask your own clinic for a current estimate.
Because a first impaction can become a recurring problem, the cost question often turns into an insurance question. Petful's guide to whether pet insurance is worth it weighs premiums against a bill like this, and a plan such as Lemonade pet insurance can be quoted online for a number to compare.
How to Prevent Anal Gland Problems in Cats
The sacs empty when firm stool presses on them, so anything that keeps stool soft or infrequent leaves them full. VCA lists obesity, chronic diarrhea, chronic constipation, inflammatory bowel disease, and allergies, including food allergies, as the reasons anal sac disease recurs in cats. Three practical questions come up here. How to stop a cat's bum from smelling starts with stool quality, because firm stool empties the sacs. Is it okay to wipe a cat's bum? Yes, with an unscented pet wipe when stool is stuck in the fur. And why does a cat have poop on his bum at all? Usually soft stool, long fur, or a cat too stiff or overweight to groom the area.
What can I feed my cat to help express his glands? No food expresses the sacs directly, but diet shapes the stool that does the job and keeps the rear from smelling between visits:
- Keep the cat lean. Obese cats have weaker anal muscle tone, and PetMD names avoiding obesity as a top prevention.
- Fix soft stool first. If loose stool lasts more than a few days, have your vet check for parasites and diet intolerance. A probiotic such as Purina Pro Plan FortiFlora for cats may then help firm things up; the feline evidence is modest, so treat it as support, not treatment.
- Add fiber if your vet agrees. Fiber increases fecal bulk, giving the stool more mass to press the sacs. A spoonful of plain canned pumpkin, such as Nummy Tum-Tum pure pumpkin, is the usual start, introduced gradually.
- Keep the rear clean. A little stool on the fur can happen after soft stool, but not routinely, and wiping your cat's bottom is fine. For a long-haired or overweight cat that cannot clean itself, cleaning is simple: trim the fur under the tail and use a damp cloth or unscented butt wipes for cats.
- Supplements. Glandex for cats and similar fiber blends are discussed in the next section; they are a maybe, not a fix.
Parasite prevention rounds this out, since tapeworm and fleas cause the same scooting.
Do Anal Gland Supplements Like Glandex Work for Cats?
Does Glandex really work for cats? The evidence is thin. Glandex for cats and similar products combine fiber, a probiotic, and omega-3 fatty acids, and the logic is sound: bulkier stool and a healthier gut should help the sacs empty. But we could not locate a published, controlled trial showing Glandex reduces anal sac problems in cats specifically; the case rests on the general logic of fiber, not feline outcome data.
A cat with a history of impaction and slightly soft stool may still do better on added fiber, branded or plain pumpkin. Ask your veterinarian first, especially for a cat with inflammatory bowel disease or a food allergy, and never use a supplement to delay a visit for a cat that is already scooting, swollen, or leaking.
Cat Anal Gland Questions
Uncomfortable rather than agonizing for a healthy sac; most cats object more to the restraint than the squeeze. It is worse when the sac is inflamed or abscessed, which is why VCA notes the procedure may require sedation, and many vets use mild sedation for a sore cat so the sac can be emptied and flushed without a struggle.
Cats release a little anal sac secretion involuntarily when startled on your lap, or when so relaxed that the anal muscles loosen. A rare fishy waft needs only a wipe. If it happens more than once a week, or comes with scooting, licking, or swelling beside the anus, the sacs are probably overfull and your veterinarian should check them.
Some offer external expression only, pressing from the outside, which is safe only for a healthy, mildly full sac. A groomer cannot examine inside the rectum or tell an impaction from an early infection, and should never press a sore or swollen sac, so a cat with any signs of a problem belongs with a veterinarian.
Yes. Both sexes have the same pair of anal sacs at the four and eight o'clock positions and can develop impaction, infection, or an abscess. Sex does not change the risk; body weight, stool quality, allergies, and age matter far more.
Dog owners who landed here will find the canine version, which is more common, in Petful's guide to anal sac glands in dogs.
BVMS, MRCVS
Dr. Pippa Elliott, BVMS, MRCVS, is a veterinarian with nearly 30 years of experience in companion animal practice. Dr. Elliott earned her Bachelor of Veterinary Medicine and Surgery from the University of Glasgow. She was also designated a Member of the Royal College of Veterinary Surgeons. Married with 2 grown-up kids, Dr. Elliott has a naughty Puggle named Poggle, 3 cats and a bearded dragon.
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