CONDITION
Lipomas
A lipoma is a benign growth made of fat cells that develops under the skin. These soft, moveable lumps are among the most common masses found in dogs, particularly as they grow older, and they occur occasionally in cats as well. They do not spread to other parts of the body and typically grow slowly over months or years. Most owners first notice a lipoma as a soft lump beneath the skin that moves easily when touched. The lump may appear on the chest, belly, or limbs, though it can develop almost anywhere. Many dogs live comfortably with one or several lipomas that never require treatment, though some masses can grow large enough to affect movement or quality of life depending on where they sit. This page explores what lipomas look like and feel like, how they differ from other kinds of lumps, the ways they can be investigated, and the approaches that exist when a lipoma becomes problematic. It also considers when observation alone may be appropriate and when further steps might be worth discussing.
Why this matters now
Lipomas typically develop in middle-aged to older dogs, often becoming more numerous with age. They grow slowly over months to years and may go unnoticed until they reach a certain size. Some dogs develop multiple lipomas throughout their lifetime.
These fatty tumours generally grow slowly and remain soft and mobile. Most maintain a benign character indefinitely. Occasionally, lipomas may reach sizes that affect mobility or comfort depending on their location. Regular monitoring helps distinguish stable lipomas from other masses that may behave differently.
Signals & patterns
Early signals
Small, soft lump under the skin
Often discovered during grooming or petting as a movable, doughy swelling beneath the skin.
Symmetrical, rounded shape
Lipomas typically have smooth, regular contours and feel uniform throughout.
Lump moves freely when manipulated
Unlike some other masses, lipomas are usually not attached to underlying tissues and slide easily under the skin.
No pain on palpation
Dogs typically show no discomfort when the area is touched or gently squeezed.
Later signals
Gradual increase in size
Over months or years, the mass may slowly enlarge, though growth rate varies considerably.
Multiple similar lumps appearing
Dogs prone to lipomas often develop additional masses in various locations.
Large masses affecting movement
Lipomas in certain locations, such as armpits or between legs, may eventually impede normal gait if they grow substantially.
Click to read about the biological mechanisms
How this is usually investigated
Investigation aims to confirm the benign nature of a mass and distinguish lipomas from other tumour types. Various approaches offer different levels of certainty.
Physical examination
Fine needle aspirate
Imaging
Surgical biopsy or excision
Options & trade-offs
Management depends on the lipoma's size, location, and whether it causes any problems. Various approaches may suit different situations.
Monitoring without intervention
Regular observation and measurement of stable, confirmed lipomas.
Trade-offs: Appropriate for small, non-problematic masses. Requires periodic reassessment to detect any changes in character or growth rate.
Surgical removal
Excision of the lipoma and surrounding capsule.
Trade-offs: Provides definitive removal and histopathological confirmation. Involves anaesthesia and surgical risks. Earlier removal of smaller masses is generally simpler than waiting until they grow larger.
Liposuction or debulking
Reducing the mass size through aspiration techniques.
Trade-offs: Less invasive than full excision but may not completely remove the lipoma. Regrowth is possible as residual tissue remains.
Mapping and documentation
Systematic recording of mass locations and sizes over time.
Trade-offs: Essential for monitoring dogs with multiple lipomas. Helps identify new masses or changes requiring investigation.
Common misconceptions
"All lumps on older dogs are probably harmless lipomas"
Many different tumour types occur in dogs, some requiring prompt attention. Any new mass warrants veterinary assessment to determine its nature.
"Lipomas will go away if the dog loses weight"
Lipomas are tumours, not simply areas of excess body fat. Weight loss does not resolve them, though it may make them more apparent.
"Small lipomas never need attention"
Whilst many lipomas remain innocuous, confirming the diagnosis is valuable. Small masses are also generally easier to remove if removal becomes warranted.
Related conditions
Histiocytoma
Histiocytomas and lipomas are both benign skin masses commonly found in dogs, though histiocytomas typically appear in younger animals and often resolve on their own, whereas lipomas tend to develop in older dogs and persist. Both may present as discrete lumps under the skin, and distinguishing between them often involves fine-needle aspiration or monitoring growth patterns over time.
Lymphoma in Dogs
Lymphoma can occasionally present as soft tissue masses that may superficially resemble lipomas on physical examination, though lymphoma masses are typically firmer, may involve multiple sites, and are associated with systemic signs. Fine-needle aspiration or biopsy can distinguish benign fat from lymphoid malignancy when a lump's behaviour or characteristics raise concern.
Obesity in Dogs
Obesity and lipomas can co-exist in the same dog, and distinguishing between generalised adipose tissue and discrete lipomas can sometimes be challenging on palpation alone. Both involve accumulation of fat, though obesity reflects whole-body energy imbalance whereas a lipoma is a localised benign growth independent of overall body condition.
Osteoarthritis in Dogs
Lipomas and osteoarthritis may both become more apparent as dogs age, and large lipomas situated near joints or limbs can occasionally contribute to mechanical discomfort or altered gait, particularly when mobility is already compromised by joint disease. In such cases, the combined effect on movement may be greater than either condition alone.
Maintaining a simple record of lump locations and approximate sizes can help track any changes over time. Noting whether lumps remain soft and mobile, or develop any different characteristics, provides useful information for veterinary discussions. Owners might consider whether a mass is growing, changing in texture, or beginning to affect the dog's comfort or movement.
Last reviewed: 24 April 2026 · Dr Alastair Greenway MRCVS