Fatty lumps, also known as lipomas, are common in dogs, especially as they get older. They are a type of tumour, but most of the time cause no problems.
Most often, fatty lumps grow slowly in one place and your dog won’t even notice it. It is always best to confirm if a skin lump is a lipoma, a simple test called a Fine Needle Aspirate can usually achieve this. Many fatty lumps can be monitored, but if they are growing quickly or causing issues, surgery should not be delayed. Some fatty lumps can grow very large, break the skin, or get in the way of moving or resting.
What are fatty lumps in dogs?
A fatty lump starts when a fat cell starts multiplying without control. This happens most often right under the skin, but can happen in the chest or abdomen as well.
Some fatty lumps can grow into the muscles, these are called infiltrative lipomas and are much more likely to cause discomfort or complications.
Most fatty lumps will barely increase in size from week to week.
Rarely, a fatty lump can be cancerous; these are liposarcomas. These grow much faster and can spread to other parts of the body.
Speak to a vet if your dog has a skin lump that is changing quickly.
Symptoms of fatty lumps in dogs
- Soft, squishy lump under the skin. Can feel a bit firmer if the skin in the area is quite tight.
- The lump usually moves with the surrounding skin. If not, it could be an infiltrative lipoma.
- Most lipomas grow very slowly over weeks to months
- There should be no pain or redness; if these are present, there is likely a complication or a different problem going on. Find out more in our article on lumps in dogs
Dogs at higher risk for fatty lumps
- Older dogs are at higher risk for developing fatty lumps, as with most types of tumours.
- Overweight dogs are also at higher risk, and fatty lumps tend to be bigger.
- In people, the tendency to develop fatty lumps is known to run in families and be associated with genetic conditions. This is not known for sure in dogs, but some breeds seem more prone to getting fatty lumps. These are the Labrador, Doberman, Weimaraner, Dachshund, Miniature Schnauzer, Golden Retriever and Cocker Spaniel.
Diagnosis of fatty lumps in dogs
A lipoma can be suspected on examination and palpation, but to know for sure, tests are required. There are two main options:
- Fine Needle Aspirate (FNA): This is usually simple to do, causes little discomfort, and will be able to diagnose most lipomas.
- Biopsy: if the FNA is inconclusive, a biopsy may be done. This requires anaesthesia and surgery but is the most reliable way to know exactly what is going on.
In cases where the fatty lump is growing into the muscle or inside the body, it may be necessary to do more advanced tests like x-rays or a CT scan.
Vet treatment of fatty lumps in dogs
If a lipoma has been confirmed and it’s not causing any problems, your vet may recommend keeping an eye on it. Most fatty lumps grow very slowly and never cause any issues. If problems arise, surgery is the only treatment option, but is usually simple and effective. Your vet may recommend this if the lump:
- Causes any discomfort or pain
- Gets in the way of movement, usually from being on a leg or near a joint
- Becomes damaged or infected
- Is getting quite big and could break the skin or lead to one of the complications above.
An infiltrative lipoma is more difficult to manage, especially if located between muscles. Surgery can still be done, but often the lump grows back. Radiation therapy at a specialist centre may be necessary in these cases.
Cancerous fatty lumps are also treated with surgery and radiation therapy.
Home treatment of fatty lumps in dogs
Fatty lumps are not painful if there are no complications. Your vet may recommend monitoring the lump. It may be useful to measure the lump every few weeks, this is best done with callipers. Another good option is to take a photo of the lump, ideally including something of known size in the image for comparison. Other useful things to monitor are:
- Whether the lump moves with the skin
- How the skin looks over and around the lump
- Any signs of pain, such as licking or defending the area
Prevention of fatty lumps in dogs
Avoiding excess body fat is the best way we can help prevent fatty lumps in dogs. If they are already present and the dog is overweight, healthy weight loss will often cause the tumours to shrink. Unfortunately, they will not disappear completely. Please don’t hesitate to ask a vet or vet nurse if you would like help managing your pet’s weight.
When to worry
When to worry about a fatty lump in your dog
It’s best to have your vet confirm that it is a fatty lump. If this has been done and no treatment is recommended, speak to your vet again if you notice any of the following:
- The lump becomes irregular in shape or texture
- Skin over or around lump becomes red or black
- The lump starts growing rapidly
- Your dog starts paying attention to the lump
- The lump is affecting the way your dog moves or lies.
If you’re unsure, our Joii vets are available 24 hours a day for advice.