Fatty tumors in dogs

A fatty tumor, technically called a lipoma, is a benign lump quite commonly found in middle age and older dogs. The lumps are composed of fat surrounded by a membrane. Lipomas can be found almost anywhere on your dog's body. They are moveable if you press them gently, non-painful, and will generally produce no changes in the skin above them. Dogs may develop one lipoma or multiple lipomas. It appears that overweight dogs are more prone to developing these lumps. Lipomas are not dangerous, but some lipomas may grow large enough to cause your dog discomfort or interfere with your dog's movement.

If your dog's diagnosis was made on the basis of a physical exam only, then the diagnosis is actually only an educated guess. Although a veterinarian may have a lot of experience seeing lumps and bumps, only a biopsy of the lump tissue can provide a definitive diagnosis. Some veterinarians prefer to perform first a fine needle aspirate of the lump in which a tiny needle is inserted into the lump to take a sample for evaluation. An aspirate can be performed without anesthesia and is relatively painless. The problem with fine needle aspirate results is that they can give false readings that do not reflect a true representation of the lump's characteristics. The only way to make a definitive diagnosis regarding the lump is to have it removed for proper evaluation.