Fatty lumps, also known as lipomas, are uncommon in cats. They are a type of tumour, but most of the time they cause no problems. Always have any skin lumps on your cat checked by a vet.
Most fatty lumps grow slowly and cause no discomfort. However, many skin lumps in cats look similar, and other lumps can be dangerous. If a lipoma (fatty lump) is confirmed, sometimes this can be monitored. If it starts growing quickly or changing, surgery should not be delayed.
What are fatty lumps in cats?
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. Some cats can develop several fatty lumps over time.
Rarely, a fatty lump can be cancerous; these are liposarcomas. These grow much faster and spread to other areas of the body.
Speak to a vet if your cat’s skin lump is changing quickly.
Symptoms of fatty lumps in cats
- 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.
Cats at higher risk for fatty lumps
- Older cats are at higher risk for developing fatty lumps, as with most types of tumours.
- Siamese cats may be more likely to develop fatty lumps.
Diagnosis of fatty lumps in cats
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 cats
- Because lipomas are uncommon in cats, unlike skin cancer, your vet may recommend surgery to remove any lump to be safe. This is usually fairly simple when the lump is superficial and small.
- 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 cats
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 cats
Avoiding excess body fat is always better for health, but this doesn’t appear to affect fatty lumps in cats.
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 cat
It’s best to have your vet test any skin lump on your cat. 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 cat starts paying attention to the lump
If you’re unsure, our Joii vets are available 24 hours a day for advice.