Do Fatty Tumors On Dogs Get Hard?

Fatty tumors, also known as lipomas, are common benign (non-cancerous) growths that develop on or under a dog’s skin as they age. A lipoma is a lump of fat that forms a soft, moveable mass under the skin, usually on the dog’s trunk or upper legs, but they can grow anywhere on the dog’s body. Lipomas are typically slow-growing, benign masses that rarely impact a dog’s health in a serious way (source).

What are fatty tumors?

Lipomas are benign fatty tumors that commonly form between a dog’s skin and muscle layer [url]. They are soft, movable lumps made up of fat cells that clump together in a capsule. Lipomas are one of the most frequent types of lumps found on dogs, especially in middle-aged and older dogs [url].

Lipomas typically feel soft and spongy. They are usually not attached to surrounding tissues and can easily be moved around under the skin. Lipomas are usually round or oval in shape and range from pea-sized to several inches wide. They have defined edges and often feel like doughy balls of fat under the skin [url]. Lipomas are usually covered by normal skin and fur.

What causes them?

There are several risk factors that may contribute to the development of fatty tumors in dogs:

Breed – Certain breeds like Labrador Retrievers, Miniature Schnauzers, Dachshunds, and Cocker Spaniels seem predisposed to developing lipomas. The exact reason is unknown but may be related to genetics (Fatty Tumor (Lipoma) in Dogs | Thornton Vets).

Obesity – Overweight dogs tend to develop lipomas more frequently. Excess fat cells may multiply abnormally and form lumps (Lipomas and Lumps on Dogs: Common Causes).

Age – Most lipomas develop in middle-aged to older dogs, between 6-10 years. The risk increases as dogs get older (What to Know About Lipoma in Dogs).

Diet – Poor quality diets high in carbohydrates and toxins may contribute to fatty tumor development. However, the link between diet and lipomas requires more research.

Hormones – Hormonal influences are suspected in some cases, as lipomas may rapidly enlarge. However, there are no definitive studies proving a hormonal cause.

Trauma – Injury to an area is thought to potentially trigger lipoma formation in some cases. However, this has not been conclusively proven.

Common locations

Lipomas most commonly develop in areas where dogs have more fatty tissue, usually under the skin. According to VCA Animal Hospitals, “Lipomas can grow anywhere, but the most common place is under the skin where fat is normally present.” Some of the most common locations for lipomas in dogs include:

– Abdomen and chest – Areas like the chest, belly/abdomen, and armpits tend to accumulate more fatty tissue and are common sites for lipomas. According to WebMD, lipomas often grow on a dog’s abdomen, chest, or legs.1

– Neck and shoulders – The neck/shoulders can also develop fatty deposits. Lipomas may form in these areas, though they are less common than the abdomen or chest.2

– Older dogs – Older dogs tend to develop more fatty tissue as they age. Therefore, lipomas become more common in senior dogs compared to younger dogs.3

Signs and symptoms

The most common sign of a lipoma on a dog is a soft, moveable lump under the skin, according to WebMD ( Lipomas are usually oval or round shaped and most often feel spongy or soft. They are often located just beneath the skin, allowing them to move easily when touched. PetMD notes that the borders of a lipoma lump are also usually well-defined (

Common locations for lipomas in dogs include the chest, abdomen, upper legs, shoulders and armpits. However, they can develop anywhere on the body. Embrace Pet Insurance states that lipomas grow slowly over time, ranging from the size of a grape to the size of a baseball (

Lipomas are usually soft and pliable. They typically only cause problems if they grow large enough to interfere with movement or impede organ function. Most lipomas in dogs are benign and painless. However, on rare occasions they can become cancerous. Pet owners who notice a rapidly growing lump or one that seems painful should have it evaluated promptly by a veterinarian.

Do They Get Hard?

Lipomas typically start out soft, doughy, and movable under the skin. However, over time some lipomas can develop a firm or hardened component [1]. This occurs as fibrous tissue and calcium deposits accumulate within the tumor. Hardened lipomas are more common in older dogs.

While most lipomas remain soft, up to 20% are reported to become firm and immobile [2]. The hardening does not necessarily indicate malignancy, but a lipoma that rapidly grows and hardens should be evaluated by a veterinarian. They may recommend biopsy or removal to confirm it is benign.

In general, any rapid changes to a lipoma’s size, shape, or texture warrant a recheck. A lipoma that suddenly becomes painful, inflamed, ulcerated, or inhibits movement also requires prompt veterinary attention [3]. While not all hard lipomas are cancerous, it’s important to monitor them closely and report changes to your veterinarian.


Veterinarians will typically diagnose lipomas through a combination of a physical exam, imaging tests, and biopsy. During the physical exam, the vet will look for lumps under the skin that feel soft and movable, which is characteristic of a lipoma tumor. They may use a needle and syringe to aspirate or suction out some cells from the mass to examine under a microscope. This is called a fine needle aspiration or FNA.

Imaging tests like x-rays, ultrasounds, or CT scans can also help visualize the shape, size, and location of the mass. These tests allow vets to see if the mass is contained within the fatty tissues or if it is attached to deeper tissues. Ultrasound is often the preferred imaging modality for diagnosing lipomas as it provides excellent visualization of soft tissue structures.

Finally, a biopsy may be performed by surgically removing all or part of the tumor and sending a tissue sample to a pathology lab for examination. Examining the microscopic characteristics of the tumor cells can definitively diagnose a lipoma versus other types of tumors. However, since lipomas are usually benign, vets may diagnose them through the physical exam and imaging alone, without a biopsy in uncomplicated cases.

Overall, vets have several diagnostic tools at their disposal to accurately identify lipomas in dogs, ranging from physical examination to imaging tests to microscopic examination of cells. These methods allow them to distinguish harmless fat tumors from more serious growths. For more information, see the VCA Hospitals and PetMD sources.


The most common treatment for fatty tumors in dogs is surgical removal, especially if the tumor is affecting the dog’s mobility or quality of life. According to the VCA Animal Hospitals, “The single most effective treatment for lipomas is surgical removal. It is best to remove these masses when they are small; the surgery is usually less invasive” (

Some vets may choose to monitor small fatty tumors that are not causing issues instead of removing them right away. However, WebMD notes that “The best treatment for lipoma in dogs is surgical removal, but some vets also opt for monitoring small lipomas that don’t impede your dog’s movement or quality of life” (

There are few medication options for treating fatty tumors in dogs. Steroids may help shrink the tumors temporarily in some cases. Home remedies like apple cider vinegar, turmeric, and dietary changes may help prevent fatty tumors but are not proven treatments. Embrace Pet Insurance recommends surgical removal for problematic fatty tumors, noting home remedies have “little scientific evidence that they work” (


While there’s no guaranteed way to prevent fatty tumors in dogs, there are some steps owners can take to help reduce the risk. According to Wag Walking, ensuring your dog maintains a healthy weight is one of the best ways to lower their chances of developing fatty tumors. Overweight and obese dogs are more prone to lipomas. Feeding your dog a high-quality diet formulated for their life stage, breed size, and activity level can help them stay trim.

Giving your dog plenty of exercise is also recommended, as an inactive lifestyle can contribute to weight gain. Aim for 30-60 minutes of activity per day through walks, play time, or other exercise. Additionally, providing ample fresh water helps flush toxins from the body that may contribute to tumor growth. According to Embrace Pet Insurance, while no foolproof prevention exists, maintaining your dog’s ideal weight gives them their best shot at avoiding lipomas.


In summary, fatty tumors or lipomas are common benign lumps that form under a dog’s skin. They are usually soft, movable masses that rarely impact a dog’s health. However, in some cases they can grow large enough to interfere with movement or functional capacities. While the underlying cause is unknown, obesity and genetics may play a role.

Most lipomas do not require any treatment. But larger, invasive, or problematic lipomas may necessitate surgical removal. Preventative measures like maintaining a healthy weight may help reduce risk. It’s important to have any new lumps or growths evaluated by a veterinarian, especially if they rapidly increase in size. They can use diagnostic tests to confirm it is just a harmless fatty mass.

While lipomas generally do not indicate serious medical conditions, abnormal or cancerous growths are possible. Routine wellness exams allow for early identification and treatment of any problematic lumps. Catching tumors when they are small optimizes outcomes. Your veterinarian is your best resource for monitoring any fatty tumors and determining if or when removal may become necessary.

Scroll to Top