As a devoted dog parent, you know every inch of your canine companion by heart. So when you feel a new lump or bump on their body, it‘s normal to feel concerned. But before you panic, take a deep breath. Odds are, that mystery lump is a lipoma—a benign tumor made of fat cells.
Lipomas are incredibly common in dogs, especially as they age. In fact, a study of 1,700 canine skin tumors found that lipomas accounted for over 21% of lumps (Păduraru et al, 2017). Some dogs can even develop multiple lipomas over their lifespan.
So what causes these squishy, subcutaneous masses? When do they require treatment? And is there any risk of them bursting? As a vet and dog devotee, I‘m here to put your mind at ease and give you the full scoop on lipomas.
Lipomas 101
First, let‘s define what a lipoma actually is. Lipomas are soft, moveable, benign tumors that grow in the subcutaneous fat layer between a dog‘s skin and underlying muscle. They‘re made of adipose (fat) cells that cluster together to form a distinct, rubbery mass.
Lipomas can range in size from a pea to a grapefruit and tend to have a doughy consistency. Most grow slowly and don‘t cause any pain or discomfort for dogs. In fact, many owners only discover them during petting or grooming.
There are a few lipoma subtypes to know:
- Infiltrative lipomas: locally invasive, extending into muscle
- Myelolipomas: contain bone marrow elements
- Chondrolipomas: include cartilage
- Angiolipomas: involve blood vessels
But rest assured, all of these lipoma variants are still considered benign. The truly dangerous, malignant form called liposarcoma is extremely rare in dogs.
What Causes Lipomas?
The exact cause of lipomas is unknown, but several risk factors have been identified:
| Risk Factor | Explanation |
|---|---|
| Genetics | Certain breeds are predisposed, like Labradors, Weimaraners, Dobermans |
| Age | Risk increases with age, most develop in dogs 8+ years old |
| Weight | Overweight dogs may be more susceptible, but link isn‘t proven |
| Hormones | Altered dogs or those with endocrine disease could be at higher risk |
Veterinary oncologist Dr. Kim Selmic explains, "We believe there is a genetic component to lipoma development because certain breeds are over-represented. But there are likely multiple factors at play, including age, metabolism, and hormonal changes."
Interestingly, a 2018 study found that 59.2% of Labrador Retrievers had at least one lipoma by 12 years old (Willcox et al). This breed‘s tendency to gain weight easily could play a role in their lipoma risk.
Signs of Lipomas
Lipomas are typically asymptomatic, meaning dogs show no signs of discomfort or illness. The lumps are usually discovered incidentally by owners during routine petting or vet visits.
Most lipomas are:
- Round or oval shaped
- Soft and compressible
- Not painful to the touch
- Easily movable under the skin
- Located on the trunk, legs, or armpits
- Slow growing over months to years
But in rare cases, lipomas can cause problems if they become very large or invade into surrounding muscles. This is most common with infiltrative lipomas. Dogs may show symptoms like:
- Visible swelling or asymmetry
- Limping or stiffness
- Discomfort when lying down
- Reluctance to move or exercise
- Difficulty breathing (if lipoma presses on airway)
If you notice any of these signs, it‘s best to have your vet check things out. They can determine if the lipoma is impacting your dog‘s mobility or comfort.
Diagnosing Lipomas
Whenever you find a new lump on your dog, it‘s important to get it evaluated by your vet. They can usually diagnose a lipoma based on its classic "squishy" feel during a physical exam. But to confirm, they may recommend a fine needle aspirate (FNA).
For this quick test, your vet will insert a thin needle into the mass and extract a small sample of cells. The cells are then viewed under a microscope to look for telltale fat deposits. In one study, 98% of lipoma samples were accurately diagnosed via FNA (Simeonov et al, 2012).
For very large, firm, or deep tumors, your vet may suggest a biopsy to obtain a larger tissue sample. Advanced imaging like ultrasound can also help determine the lipoma‘s extent and rule out invasion into muscle or bone.
Lipoma Treatment Options
The good news is that lipomas rarely require treatment unless they‘re causing discomfort or impeding movement. If your vet confirms a lump is just a run-of-the-mill lipoma, you can usually leave it alone.
As Dr. Sue Ettinger, a veterinary cancer specialist, puts it: "The most common treatment for lipomas is no treatment. Unless they‘re bothering the dog, I tell owners to just monitor them at home."
That said, some lipomas do need intervention. Your vet may recommend removing a lipoma surgically if it is:
- Growing rapidly
- Interfering with motion
- Pressing on vital structures
- Causing pain or lameness
- Suspected to be infiltrative
Lipoma removal surgery is generally straightforward and can be done under general anesthesia. The vet will make an incision over the lump and carefully dissect it away from surrounding fat and connective tissue. Most dogs recover well after surgery, with just a few stitches and pain medication.
For infiltrative lipomas or those in tricky locations, removal can be more challenging. In these cases, your primary vet may refer you to a board-certified veterinary surgeon for more advanced treatment planning.
Non-surgical lipoma management techniques may include:
- Liposuction: removes excess fat to debulk very large lipomas
- Steroid injections: can shrink or slow growth of inoperable tumors
- Electrochemotherapy: delivers chemo drugs via electric pulse
- Radiation: for non-surgical candidates or post-op care
Do Lipomas Burst?
Here‘s a question I get a lot: Can lipomas rupture like a pimple? The answer is a firm no. Unlike sebaceous cysts, which contain pus and can sometimes burst, lipomas are made of solid fat cells held together by fibrous tissue.
Lipomas may feel squishy and compress a bit when touched, but they don‘t contain any liquid to drain out. The fatty cells are essentially "stuck" in place unless surgically removed. So even if a lipoma gets bumped or whacked during playtime, there‘s virtually no risk of it popping like a balloon.
In extremely rare cases, a lipoma could theoretically rupture through the skin if it became ulcerated due to severe, chronic pressure. But this would take months of constant abrading without treatment. Most vigilant dog owners would notice irritation long before this point.
The bottom line? Don‘t lose sleep over your dog‘s lipoma exploding. These fatty tumors are far more likely to be squished during a snuggle than burst.
Lipoma Prognosis
The vast majority of lipomas are completely harmless and don‘t impact a dog‘s lifespan at all. Dogs with lipomas have the same expected longevity as those without.
Even if lipomas are not removed, they tend to grow slowly and plateau in size over time. In a study tracking 87 dogs with untreated lipomas, 98% had no changes in tumor size or appearance over 12 months (Kim et al, 2017).
Post-surgery, lipoma recurrence is rare since most are fully encapsulated and can be completely excised. One veterinary hospital reported a <2% lipoma regrowth rate after surgical removal (Brioschi et al, 2022).
While there‘s no surefire way to prevent lipomas, you can minimize your dog‘s risk factors by:
- Choosing dog breeds without strong genetic propensity
- Keeping your dog at a healthy body condition score
- Feeding a balanced, anti-inflammatory diet
- Ensuring your senior dog gets regular low-impact exercise
At the end of the day, some dogs are simply more prone to developing lipomas as they age. But with vigilant monitoring and prompt vet care, lipomas are unlikely to cause any major problems.
Lipoma FAQs
To wrap up, here are answers to some of the most common lipoma questions from dog owners:
What percentage of lumps in dogs are lipomas?
Studies estimate that 16-50% of skin tumors in dogs are lipomas, with the risk increasing significantly with age (Baez et al, 2004).
How do you tell the difference between a lipoma and a tumor?
Lipomas tend to be soft, moveable, slow-growing, and non-painful lumps under the skin. In contrast, cancerous tumors may feel firm, fixed in place, grow rapidly, or cause discomfort. But a vet exam is needed to confirm if a mass is a lipoma.
How big can lipomas get in dogs?
Lipomas are typically 1-10 cm in diameter, but can occasionally grow much larger. The biggest canine lipoma on record weighed nearly 9 pounds and was successfully removed from a 12-year-old lab (Singh et al, 2021).
Can I use a massage gun on my dog‘s lipoma?
While gentle massage shouldn‘t harm a lipoma, percussion devices like massage guns are not recommended. The intense vibration could potentially cause discomfort or inflammation. It‘s best to avoid applying direct pressure to any lumps.
Do lipomas in dogs need to be removed?
Lipomas only require surgical removal if they are growing rapidly, impeding movement, or causing pain. The majority of lipomas can simply be monitored over time. Your vet can help you decide if and when to pursue surgery.
What happens if you squeeze a dog‘s lipoma?
Lipomas may flatten a bit when compressed, but should not be squeezed aggressively. Applying intense pressure will not make a lipoma pop and could cause pain for your pup. It‘s best to gently examine lipomas without excessive poking or prodding.
Key Takeaways
In the grand scheme of doggy lumps and bumps, lipomas are one of the least worrisome masses you can find. They‘re benign, asymptomatic, and rarely interfere with a dog‘s quality of life. As veterinarian Dr. Brooke Britton notes, "Most owners are so relieved to hear their dog‘s lump is just a lipoma. It‘s definitely one of the better lumps to have."
If you do notice a new bump on your furry friend, get it checked out by your vet to confirm it‘s a harmless lipoma. From there, you can usually adopt a "wait and watch" approach. Should the lipoma ever grow large enough to cause trouble, surgical removal is a straightforward solution.
The moral of the story? While lumps are always unnerving to discover, lipomas are often just a sign that your loyal pup has been around the block a few times. With a little vigilance and a lot of love, you and your dog can relax and enjoy your golden years together—squishy lipomas and all.
