Lipomas (Fatty Lumps) in Dogs

What a Lipoma Looks and Feels Like

A typical lipoma is a soft, rounded lump under the skin that moves when you push it. It's usually painless and grows slowly. Common spots are the chest, sides, belly, back and upper legs.^1,5,2 Many dogs have more than one.⁹ Lipomas don't usually shrink or go away on their own; they tend to grow slowly over time.^5,9

Which Dogs Get Lipomas?

• Middle-aged and older dogs, especially from about 7 years old.^5,6
• Heavier and overweight dogs. Dogs at or above the average adult weight for their breed had about twice the odds.^6,1
• Breeds including Weimaraners, Dobermans, Labrador Retrievers and Miniature Schnauzers.^6,2
• Neutered dogs. Some references say females are more often affected, but the large UK study found neutered males and neutered females both had higher odds than unspayed females.^6,2

How Vets Diagnose a Lipoma

Your vet will feel the lump and usually take a fine-needle aspirate: a thin needle collects cells to look at under a microscope. It's quick, usually needs no sedation, and is enough to diagnose most lipomas.^10,2 The main reason to do it is to rule out look-alikes such as mast cell tumors.^2,3

A needle sample can't tell an ordinary lipoma from an infiltrative one, so if a "lipoma" is firm, fixed in place or growing quickly, your vet may suggest a biopsy or a CT scan.^10,11

Infiltrative Lipomas and Liposarcomas

• Intermuscular lipomas grow between muscles, most often in the back of the thigh or the armpit. They can cause lameness or make a dog hold a leg out. Surgery usually works well, and in one study none came back.^12,13
• Infiltrative lipomas are rare. They are made of normal-looking fat but grow into muscle and other tissue, so they're treated more like a low-grade cancer. They come back after surgery in about a third of cases, and radiation may be added.^14,9,11
• Liposarcomas are rare, malignant fatty tumors, more common in older dogs. They seldom spread but often regrow, so wide surgery is recommended.^15,2

Does a Lipoma Need to Be Removed?

Most ordinary lipomas don't. Once a needle sample confirms it, your vet will usually suggest measuring it and rechecking it.^1,10 Removal is usually suggested if a lipoma:

• Interferes with walking, leg movement or breathing, especially in the armpit^1,5
• Grows quickly, becomes very large or changes in firmness^1,5
• Is intermuscular or infiltrative^10,14

Recovery typically takes 7 to 10 days with a cone.⁵ Fluid build-up under the wound (a seroma) is the most common problem afterwards.^7,10 Ordinary lipomas rarely come back after removal, but new ones can appear elsewhere.^5,10 Other options such as liposuction or injections into the lump are sometimes used, but lipomas come back more often after liposuction.¹⁰

There's no proven home remedy or supplement that shrinks lipomas.⁵ Keeping your dog at a healthy weight is good for him in any case, and heavier dogs are more likely to get lipomas.⁶

How to Monitor a Lipoma at Home

• Check your dog's skin all over once a month.¹⁶
• Measure each known lump with a ruler or tape measure, take a photo and write down the date and where it is.
• Have known lumps rechecked by your vet as often as they advise, and sooner if one changes in size, firmness or comfort.¹
• Have any new lump checked rather than assuming it's another lipoma.^2,3

For other kinds of lumps, see lumps and bumps on dogs, cysts on dogs and mast cell tumors.

Frequently Asked Questions

Can a lipoma turn into cancer?

Lipomas are benign. Liposarcoma is a separate, rare fatty cancer, and some other cancers can look like lipomas, which is why a needle sample matters.

Do lipomas hurt dogs?

Usually not. A lipoma that becomes painful, or one that presses on a leg or the chest, should be checked.

Can lipomas go away on their own?

Generally no. They usually stay the same or grow slowly.

How can I tell a lipoma from a tumor at home?

You can't reliably. Some cancers feel soft and movable too, so ask your vet for a needle sample.

Why does my dog keep getting fatty lumps?

Many older dogs get several lipomas. Age, weight, breed and neutering all raise the odds.