A lipoma is a lump made of fat. These benign fatty tumors grow slowly, and most sit between the skin and the muscle below it, though some form in deeper tissue [2]. Benign means the tumor does not spread to other parts of the body.
Lipomas are among the most common skin and under-the-skin lumps in dogs, and so are mast cell tumors [3]. For lumps in or under the skin, the recommended tests are a fine needle aspiration or a biopsy [3].
Have your vet check every new lump, even one that feels soft and moves freely. Only a sample from the lump can tell what it is.
For other kinds of lumps, see lumps and bumps on dogs.
Which dogs get lipomas
A large UK study looked at the records of more than 380,000 dogs seen at first-opinion vet practices. About 2 in every 100 dogs had a lipoma diagnosed in one year [1].
- Age: the odds rose sharply with age. Dogs aged 9 to 12 were far more likely to have a lipoma than dogs aged 3 to 6 [1].
- Weight: dogs at or above the average weight for their breed and sex had about twice the odds of dogs below it. The authors say carrying extra weight may play a part, but this still needs to be confirmed [1].
- Neutering: neutered males and neutered females had higher odds than unneutered females [1].
- Breeds: the breeds with the most lipomas in that study were the Weimaraner, Dobermann Pinscher, German Pointer, Springer Spaniel and Labrador Retriever [1].
What a lipoma looks like
A lipoma usually forms just under the skin. Many cause no problems at all, and a dog often has more than one [2]. A lump that you can feel tells you little on its own, though, because other lumps can be found in the same places. That is why the test matters more than the feel [3].
Look-alikes
Mast cell tumors. These are one of the most common skin tumors in dogs, alongside lipomas [3]. A needle sample or biopsy shows which one a lump is [3]. See mast cell tumors in dogs and cats.
Infiltrative lipomas. This is an uncommon form of lipoma that grows into the tissue around it, such as nearby muscle [4]. It can be hard to remove completely, and it often comes back when some of it is left behind [4].
Liposarcomas. These are malignant tumors of fat tissue. They are not often reported in dogs. Most are found under the skin of the trunk and the upper parts of the legs [5].
How vets find out what a lump is
A fine needle aspiration takes a few cells from the lump with a thin needle, and the cells are looked at under a microscope. Lipomas can usually be identified this way [2][3]. Your vet may also suggest a biopsy, a small piece of tissue checked under a microscope [3].
Why lipomas still need watching
Most lipomas do not need treatment. Some, though, become uncomfortable or grow large enough to get in the way of normal movement [2].
Your vet will decide whether a lipoma should be removed or watched. Removing a simple lipoma with surgery is usually all it needs [2].
For the rarer types:
- Infiltrative lipomas: removing the whole tumor with surgery is the standard approach, because pieces left behind tend to regrow [4]. Your vet may discuss other options with a specialist [4].
- Liposarcomas: the aim is to remove the whole tumor with surgery. How fully it is removed is linked to how long dogs live afterwards [5].
At home, as directed by a vet:
- note the size, place and date of each lump, so you can show your vet any change;
- do not squeeze or try to drain a lump;
- keep your dog at the weight your vet recommends;
- go back for every recheck.
Outlook
Outcomes vary between types:
- Simple lipomas are benign, and surgery is usually curative [2].
- Infiltrative lipomas often come back if part of the tumor stays behind [4].
- Liposarcomas often do well after complete removal, but some kinds behave more aggressively [5].
These are statements about groups of dogs. They cannot predict how one dog will do. Your vet can explain what this means for your dog.
When to see your vet
See your vet if your dog has:
- any new lump, even a soft one that moves freely [3];
- a lump that grows [2];
- a lump that seems to bother your dog or gets in the way when it moves [2];
- a lump that comes back after it was removed [4].
FAQ
Is a soft lump that moves always a lipoma?
No. Mast cell tumors are just as common in dogs [3], so your vet needs a sample to know.
Does a lipoma need to be removed?
Not always. Your vet will decide. Most lipomas need no treatment, but one that grows or bothers your dog may be removed, and surgery usually ends the problem with that lump [2].
Which dogs get lipomas most?
Older dogs and dogs that are heavy for their breed. In a large UK study, Weimaraners, Dobermann Pinschers, German Pointers, Springer Spaniels and Labrador Retrievers had the most lipomas [1].
The bottom line
Lipomas are benign fatty lumps that are common in older dogs. They usually sit just under the skin, but a mast cell tumor, an infiltrative lipoma or a liposarcoma can sit in the same place. That is why your vet tests new lumps with a needle sample or a biopsy. Some lipomas grow, so keep track of your dog’s lumps and see your vet about any new or changing one.
This article is for general information only and does not replace advice from your veterinarian. If your dog has a new lump, see your vet.
Sources
- O’Neill DG, Corah CH, Church DB, Brodbelt DC, Rutherford L. Lipoma in dogs under primary veterinary care in the UK: prevalence and breed associations. Canine Genetics and Epidemiology, 2018. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC6161450/
- Arango et al. Pilot study evaluating lipoma reduction with injected physiologic ice slurry. Frontiers in Veterinary Science, 2025. Open access (CC BY). https://pmc.ncbi.nlm.nih.gov/articles/PMC12312678/
- Dank G, Buber T, et al. Training and validation of a novel non-invasive imaging system for ruling out malignancy in canine subcutaneous and cutaneous masses using machine learning in 664 masses. Frontiers in Veterinary Science, 2023. Open access (CC BY 4.0). https://pmc.ncbi.nlm.nih.gov/articles/PMC10570610/
- Matsuyama et al. Outcome and Prognostic Factors of Dogs Treated for Infiltrative Lipoma Undergoing Radiation Therapy: A Retrospective Multi-Institutional Study of 29 Cases. Veterinary and Comparative Oncology, 2025. Open access (CC BY). https://pmc.ncbi.nlm.nih.gov/articles/PMC12378080/
- Badial et al. Well-Differentiated, Low-Grade Subcutaneous Liposarcoma With a Fatal Outcome in a Dog. Veterinary Medicine and Science, 2026. Open access (CC BY). https://pmc.ncbi.nlm.nih.gov/articles/PMC13054829/