Lipomas are very common tumors in dogs. These tumors are benign (not cancerous) and are typically seen in middle-aged and older dogs.
Lipomas vary widely in size and rate of growth. Because the tumors are comprised of fat cells, overweight dogs are more likely to develop lipomas and more likely to have rapid growth of the tumors.
Problems Caused by Lipomas
Though benign, lipomas can cause health issues for dogs, depending on their location on the body. If a lipoma is formed in the axillary (underarm) or inguinal (groin) area, it may inhibit the dog’s movement. Lipomas located near the penis, anus, or vulva can interfere with the dog’s ability to urinate and defecate.
Almost all lipomas are located just beneath the dog’s skin, making them easy to feel. However, some lipomas form under the muscle or even in the chest or abdominal cavity.
Lipomas found in-between or under the muscles are termed infiltrative lipomas. Because of where they grow, they are more likely to cause issues for the dog as opposed to lipomas located just under the skin.
When these tumors grow between muscle layers, they are typically called infiltrative lipomas.
Though true lipomas are benign, there are cancerous fat cell tumors in dogs. These malignant variations of lipomas are called liposarcomas. When palpated, these tumors feel very similar to lipomas, but they have more aggressive behavior. This typically includes rapid growth and recurrence after surgical removal.
How Often Do Dogs Get Lipomas?
Lipomas were found to have a 1.94% one year prevalence in a study population of dogs in the UK. A one year prevalence is the proportion of the studied population that has a particular condition at some time during a year.1
Clinically, lipomas are one of the most commonly-diagnosed tumors in dogs.
Causes of Lipomas in Dogs
As is the case with all cancers, the exact cause of lipomas in dogs is largely unknown. It is likely multifactorial, meaning that there are many factors at play. Genetics, age, heredity, health status, and environmental exposure all likely play a role in the formation of lipomas in dogs.
Diagnosing Lipomas in Dogs
The owner is often the first to notice a lipoma on their dog. These tumors are typically located on the dog’s trunk and are squishy and freely moveable.
If a lipoma is suspected, the owner should consult a veterinarian. The doctor will likely start by gathering a complete history, examining the pet, and performing a fine needle aspirate.
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A fine needle aspirate is a simple procedure that can be done in the veterinarian’s office, most often without the need for sedation. A small needle is inserted into the suspicious tumor, and a syringe is used to draw out some of the cells.
The cells from the tumor are placed onto a slide and then examined under a high-power microscope. If the veterinarian has any doubts about what he or she is seeing, the slides may need to be sent out for review by a veterinary pathologist.
If the diagnosis still isn’t clear after a veterinary pathologist’s review, a biopsy or simply removing the entire tumor may be recommended. It is important to remember that a fine needle aspirate only takes a very small number of cells and may lead to inconclusive results.
If the tumor is taken off in its entirety, it should be sent for review by a veterinary pathologist. This will allow for accurate diagnosis of the tumor type as well as a determination of the margins of the tumor. Measuring margins will ensure the entire tumor has been removed.
Will Lipomas Grow or Change Over Time?
Luckily lipomas are benign. Once a definitive diagnosis is made, there is no need to worry about the tumor spreading. However, lipomas may continue to grow and lead to health issues if not removed.
Lipomas tend to grow slowly, but can enlarge over time. A dog with a lipoma who gains weight is likely to have their lipoma grow in size.
Additionally, once a dog develops one lipoma, whether it is removed surgically or not, there is a tendency for them to produce more lipomas.
In the instance of an actual lipoma, considerations for treatment should include a determination of whether or not the tumor is causing the dog any discomfort. Some owners elect to remove unsightly lipomas for cosmetic reasons.
Lipomas that arise in the underarm, groin, and around the genitals should likely be removed as soon as possible, because the larger they grow, the more difficult complete surgical removal will be.
Smaller lipomas require smaller incisions to remove and require much less invasive surgical techniques.
Lipomas in dogs may shrink if the dog loses weight, but they will not go away without surgery. No at-home remedies will shrink or get rid of a lipoma, including diet changes, food, or supplements.
Prevention of Lipomas in Dogs
Unfortunately, there is no way to prevent lipomas in dogs. Since a dog that is overweight has a higher tendency to develop lipomas, managing your dog’s weight is the best way to help prevent lipomas, in addition to all the other benefits keeping our dogs the proper weight can have.
Frequently Asked Questions About Lipomas:
1. What are the most frequent locations for lipomas to be found in dogs?
Lipomas are most frequently found on the trunk in dogs. This includes both the chest and abdomen. It is possible, but less common, for lipomas to form on the neck and limbs.
2. Which dogs are most likely to develop lipomas?
Overweight and older dogs are much more likely to have lipomas.
Disclaimer: This website's content is not meant to be a substitute for veterinary care. Always consult with your local veterinarian for health decisions. Learn more.
Also, lipomas are more common in Weimaraners, Dobermann Pinschers, German Shorthair Pointers, Springer Spaniels, and Labrador Retrievers.1
Read More About Dog’s Lumps and Bumps:
1. “Lipoma in dogs under primary veterinary care in the UK: prevalence and breed associations.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6161450/.
Disclaimer: This website's content is not meant to be a substitute for veterinary care, diagnosis, or treatment. Always consult with your veterinarian to determine the best course of action. Read More.