Dog Lipoma (Fatty Tumor): Signs, Testing and Removal

What it usually means

A lipoma is a growth of fat cells, enclosed in a thin capsule, that forms most often in the fatty layer just under the skin. VCA calls it a common, benign fat tumor of middle-aged to older animals, and notes that many dogs have several. The Merck Veterinary Manual reports lipomas are most often found on the trunk and upper legs, and that they are more common in older, overweight females, with Doberman Pinschers, Labrador Retrievers, Miniature Schnauzers and mixed breeds at higher risk.

Most lipomas grow slowly and stay small for years, though some keep growing until they are very large. A few are less straightforward. Infiltrative lipomas grow into and between muscle layers and are harder to remove completely. Liposarcoma is the rare malignant form of a fatty tumor. Neither can be told apart from an ordinary lipoma by touch.

What a lipoma looks and feels like

The typical lipoma is a soft, squishy, dome-shaped lump under the skin that moves slightly when you push it, does not seem to hurt the dog, and is covered by normal skin and fur. It may be the size of a grape or, over years, larger than a grapefruit. Common spots are the chest, belly, flanks, armpits and upper legs.

Several other lumps can mimic a lipoma, which is why vets do not diagnose one by feel alone. Merck specifically warns that mast cell tumors can resemble lipomas, and soft-tissue sarcomas, cysts and abscesses can too. A lump that is firm, fixed in place, growing quickly, red, ulcerated, changing size from day to day or painful is less likely to be a simple lipoma.

When to call your vet today

Book an appointment for any new lump you find, even if it feels soft. A needle sample is quick, usually done without sedation, and either reassures you or catches a problem early. Measure the lump with a ruler or tape, note where it is, and take a photo so you can track it.

Call sooner if a lump grows noticeably in a few weeks, becomes hard or fixed, changes size from day to day, bleeds, ulcerates, itches, or if your dog licks or chews at it. Also call if a lump in the armpit, between the legs or near the neck starts to affect how your dog walks, lies down or uses stairs.

When it's an emergency

A lipoma itself is almost never an emergency. Lumps become urgent when they come with other signs, so see your vet or an emergency vet the same day if a lump suddenly becomes hot, swollen and painful, which can be an abscess, or if it is bleeding heavily.

Go to an emergency vet immediately if your dog has a swollen belly with weakness, pale gums or collapse, or is having trouble breathing. These are not lipoma signs, but internal masses can cause them, and they need urgent care.

What you can safely do at home

Keep a simple lump map: a sketch or photo of your dog with each lump marked, its size and the date you found it. Check monthly during grooming or a belly rub. That record lets your vet see at a glance whether anything has changed, and it means new lumps are sampled early.

Do not squeeze, lance or try to drain a lump, and do not apply creams or home remedies. Squeezing a mast cell tumor can trigger a reaction, and lancing a lump can cause infection. Helping your dog reach and stay at a healthy weight is the most useful practical step, since excess body fat is linked with lipomas and can make them larger.

What the vet will likely check

Your vet will feel the lump and its surroundings and usually perform a fine-needle aspirate, collecting cells with a thin needle to look at under the microscope. A lipoma shows mostly fat, often leaving an oily spot on the slide. If the result is unclear, a biopsy gives a definitive answer. For a deep or infiltrative lump, imaging such as ultrasound or CT may be recommended to plan surgery.

Many confirmed lipomas are simply monitored. VCA explains that removal is mainly cosmetic for benign lipomas, but important when a lump causes discomfort or lameness, for example in the armpit or between the legs, and that surgery is easier and leaves a smaller wound when the lump is small. Removed lipomas rarely come back. Infiltrative lipomas and liposarcomas need wider surgery, sometimes by a specialist surgeon, and occasionally extra treatment.

Prevention

There is no proven way to prevent lipomas, but keeping your dog lean reduces risk and makes any lumps easier to feel and monitor. Regular exercise and measured meals help, and your vet can tell you your dog's ideal body condition.

The habit that matters most is checking. Run your hands over your dog regularly, note anything new, and ask your vet to sample every new lump, even in a dog that already has several known lipomas. The next one may not be a lipoma.

This page is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your pet.

Keeping your dog lean is sensible because extra weight is linked with lipomas; a slow feeder bowl or puzzle feeder can help portion meals.