A lipoma in dogs is one of the most common tumors they can get. A lipoma is a benign (non-cancerous) tumor made up of fat cells (adipocytes). Although it is not dangerous, it can be unsightly and cause discomfort for the dog depending on the size and location of the growth. Lipomas can occur anywhere on the dog's body but are typically found on the chest, back, or abdomen, and can range in size from a few millimeters to a few inches in diameter. This article will discuss why lipomas develop in dogs and when you should be concerned.
What is a lipoma in dogs and why do they develop?
A lipoma in dogs is a benign, slow-growing mass of fat cells called adipocytes that develops by expanding rather than invading. Many lipomas are well-circumscribed and encapsulated and they do not metastasize into other parts of the body. Lipomas in dogs most commonly occur in subcutaneous tissues but can also be found within or beneath muscle layers. Lipomas are common in older dogs. Breeds that are more likely to develop them include the Labrador retriever, beagle, doberman pinscher, miniature schnauzer, American cocker spaniel, weimaraner, and dachshund.
The cause of lipomas in dogs is unknown, but veterinarians believe they develop from genetic factors. As lipomas are one of the most common benign tumors in dogs and their incidence increases with age, there is likely some genetic component to their development. Interestingly, obesity doesn't necessarily play a role in the development of lipoma in dogs.
When should you be concerned about lipomas in your dog?
Most lipomas in dogs are benign and don't require treatment. However, if your dog has a lipoma that is growing rapidly, is located on the head or neck, or is causing problems such as pain or mobility issues, then you should take him to your veterinarian. In some cases, surgery may be recommended to remove the lipoma.
A specific type of lipoma in dogs called an infiltrative lipoma is often more concerning. These lipomas invade the surrounding tissues such as muscle and can be more difficult to remove. They are also more likely to recur after surgery.
What are the symptoms of a lipoma in dogs?
Lipomas often present as one or more soft, mobile swellings beneath the skin. Some however may be firm or fixed. If the lipoma develops within major muscle groups or compresses neurological structures, your dog may experience limping or an abnormal gait.
How is a lipoma in dogs diagnosed?
Veterinarians can usually diagnose lipomas in dogs by physical examination. However, in some cases, they may need to perform cytology to confirm the diagnosis. This is a simple and painless procedure where a small needle is introduced into the mass (fine needle aspirate) and a small sample is obtained. The sample is then evaluated under the microscope to evaluate for lipocytes or adipocytes.
How is a lipoma in dogs treated?
Lipomas are usually benign, non-life-threatening tumors, so surgery or other treatments are typically only recommended if they impede motion, and function or are uncomfortable for the dog. In some cases, surgery may be recommended to remove the lipoma. If you and your veterinarian have decided to surgically remove a lipoma, the procedure is relatively straightforward. The surgery can become more challenging if the lipoma is not encapsulated and infiltrates into surrounding tissues. If the surgery has been performed properly, there is an extremely low risk of lipoma recurrence. Another factor that can make the surgery more difficult is the size of the lipoma. Lipomas that are very large need to be planned properly by your veterinarian. There is a risk of fluid accumulation and swelling called a seroma with the removal of large lipomas. This can be mitigated by placing a surgical drain in place at the time of surgery for a few days post-operatively, and/or applying warm compresses to the surgical site afterwards.
What is the prognosis for dogs with lipomas?
The prognosis for lipomas in dogs is generally very good. The vast majority of lipomas are benign and don't metastasize or cause any other health problems for the dog. If however, your veterinarian recommends surgery to remove a lipoma, there is a very low risk of recurrence with a reported recurrence rate of 2%.
A lipoma in dogs is typically just a cosmetic concern, but it can sometimes cause discomfort or problems if they are large or located in a sensitive area. They develop from genetic factors and obesity doesn't necessarily play a role in their development. Diagnosing a lipoma in dogs is straightforward and accurate if cytology is performed. If your dog has a lipoma, be sure to monitor it for changes in size or appearance and take him or her to the veterinarian if you have any concerns.