What are lipomas?
Lipomas are benign (noncancerous) fatty tumors that commonly develop in dogs, especially older dogs (source: https://vcahospitals.com/know-your-pet/adipose-lipoma-tumors). They form under the skin and are made up of fatty tissue. Lipomas can occur anywhere on a dog’s body, but are most often found on the torso, upper legs, upper back, and shoulders. They are usually soft, moveable lumps under the skin, often with a rubbery or doughy texture (source: https://www.webmd.com/pets/dogs/what-to-know-lipoma-in-dogs). Lipomas are usually painless.
What causes lipomas in dogs?
The exact cause of lipomas in dogs is not completely understood. However, research suggests there may be a genetic component, as some breeds like Labrador Retrievers, Doberman Pinschers, and Schnauzers seem predisposed to developing lipomas. Additionally, lipomas form from adipose tissue or fat cells in the body, indicating obesity and fat distribution may play a role.
According to the VCA Animal Hospitals, “Most seem to be caused by a complex mix of risk factors, some environmental and some genetic or hereditary.”1 While the root cause remains unknown, some theorize hormonal influences, trauma, or microinjuries to fat cells may trigger lipoma formation.
Overall, the development of lipomas is complex with no single known cause. Both hereditary and environmental factors likely contribute. Further research is needed to better understand the origins of lipoma formation in canines.
1 https://vcahospitals.com/know-your-pet/adipose-lipoma-tumors
How common are multiple lipomas in dogs?
Multiple lipomas are quite common in dogs. According to the Veterinary Ireland Journal, lipomas are the most common type of skin tumor diagnosed in dogs. A study found the one-year prevalence of lipomas in dogs under veterinary care was 1.94% (Veterinary Ireland Journal).
Certain breeds seem more prone to developing multiple lipomas including Doberman Pinschers, Labrador Retrievers, Miniature Schnauzers, and mixed breeds. The risk also increases with age, with most cases occurring in dogs 8 years or older. Obese and overweight dogs are also at higher risk for lipomas (VCAAnimal Hospitals).
While lipomas can occur in dogs of any age, the average age at diagnosis is around 9 years old. Since they tend to grow slowly over time, it’s common for middle-aged to older dogs to develop multiple lipomas throughout their senior years (VCAAnimal Hospitals).
When are lipomas a concern?
Lipomas are usually benign and harmless fatty tumors that commonly develop in older dogs. Though not typically a major health threat, there are some exceptions where lipomas can become problematic or concerning:
Fast growing lipomas – While lipomas generally grow slowly over months to years, any rapid enlargement should be evaluated by your vet, especially if the mass begins impairing movement.
Lipomas in areas that restrict movement – Lipomas around joints or over pressure points can begin interfering with mobility as they enlarge.
Symptoms beyond the lipoma itself – Unexplained weight loss, poor appetite, lethargy, or other systemic signs may suggest the lipoma is linked to an underlying disease process.
Rare risk of cancer – While extremely uncommon, lipomas can very rarely transform into a liposarcoma cancer. Your vet can help determine if biopsies are needed to rule out malignancy.
Overall, have any new, rapidly growing, or problematic lipomas evaluated. Though benign lipomas are usually nothing to worry about, it’s still important your vet examines any concerning changes.
Diagnosing lipomas
If your dog develops lumps under their skin, the first step is to have your veterinarian examine them. The vet will look at the location, texture, and feel of the lumps to get an initial idea of what might be causing them. According to VCA Animal Hospitals, these types of tumors can often be diagnosed just through a veterinary examination.
To confirm the diagnosis, the vet may use a technique called fine needle aspiration or FNA. This involves inserting a small needle into the lump and suctioning out some cells for examination under a microscope. Analyzing the cells can allow the vet to determine if the lump is a benign lipoma or another type of mass.[1]
Imaging tests like an ultrasound or CT scan may also be recommended. These scans can help the vet evaluate the size, shape and location of the lipomas. They can also check for any underlying issues.
Treating lipomas in dogs
In most cases, no treatment is needed for lipomas in dogs. Since they are usually benign fatty masses, lipomas don’t normally impair a dog’s health or quality of life (VCAA). However, treatment may be recommended if the lipomas become problematic.
The most common treatment is surgical removal, especially if the lipoma is in a location that impacts mobility or function. Surgery for lipoma removal is usually a simple outpatient procedure. The lipoma is excised and the incision closed with dissolvable sutures. Recovery is normally quick with minimal pain or complications (WebMD).
Some veterinarians may also recommend non-surgical injections to dissolve fat within lipomas. Drugs like liposterolic can be injected directly into the lipoma to break down the fatty tumor over time, reducing its size. However, results can be variable and multiple treatments may be needed (VCAA).
Preventing lipomas
While there is no definitive way to prevent lipomas from forming in dogs, there are some steps owners can take that may help reduce the likelihood of development:
Maintaining a lean body weight – According to petMD [1], overweight and obese dogs tend to develop lipomas more frequently. Keeping your dog at a healthy weight can help prevent excessive fatty tissue growths.
Nutritional supplements – Some supplements like fish oils, vitamin E, and lecithin may help prevent lipomas by supporting fat metabolism and skin health according to WagWalking [2]. Talk to your vet before starting any new supplements.
While not definitively proven, these proactive measures may help reduce lipoma development. But unfortunately there is no guaranteed way to prevent them entirely.
Living with a dog with lipomas
Living with a dog that has multiple lipomas requires some adjustments and close monitoring at home. Here are some tips for caring for your dog:
Monitor the lumps at home. Keep an eye on the size, shape, texture and location of each lipoma. Note any changes and alert your veterinarian, as a sudden increase in size can indicate a malignant tumor (VCA Animal Hospitals).
Help your dog maintain a healthy weight. Obesity is a risk factor for developing lipomas. Feed an appropriate diet for your dog’s size, age and activity level. Exercise regularly if your dog is able (WebMD).
Adjust exercise if mobility is impaired. Lipomas growing in areas like the limbs or chest can restrict movement and make exercise difficult. Consult your vet on safe activities or mobility aids if needed. Low-impact exercise like swimming may be an option.
When to see the vet
While many lipomas in dogs are harmless, there are some cases when you will want to have your dog seen by a veterinarian. According to the VCA Animal Hospitals, you should bring your dog in for an examination if you notice any of the following:
- A new lump appearing on your dog
- An existing lump rapidly growing in size
- Signs of pain or changes around the lump area
As Denver Vet explains, if a fatty tumor begins to grow quickly, becomes painful for your dog, or changes texture, contact your vet right away. A new lump could potentially be cancerous, so it’s important to have it checked out. Rapid growth or pain indicates something may be wrong with the lump.
While most lipomas are harmless, it’s always a good idea to point out any new lumps or bumps to your veterinarian during your dog’s annual checkup. The vet can monitor existing lipomas for changes and determine if biopsies or removal are needed. Catching a lump early on increases the chances of successful treatment. Don’t wait until your dog shows signs of discomfort before having a lump evaluated.
Outlook for Dogs with Multiple Lipomas
The outlook for dogs with multiple lipomas is often positive. Lipomas are typically benign fatty masses that do not affect the dog’s health or quality of life1. Dogs can live normally with multiple lipomas with few issues. As long as the lipomas do not impede movement, walking, or other activities, they may not require any intervention.
The key is monitoring the lipomas for any concerning changes. If a lipoma begins growing rapidly, interfering with movement, or showing signs of inflammation, it should be evaluated by a veterinarian. Surgery may be recommended to remove problematic lipomas. Otherwise, many dogs can live comfortably with multiple benign lipomas with regular veterinary checkups.
With monitoring and care, the prognosis is often excellent for dogs with multiple lipomas. These fatty masses are generally harmless, allowing dogs to live full, active lives. As long as lipomas do not transform or cause discomfort, they pose little threat in most dogs.
