What Are Lipomas in Dogs?

Lipomas are benign fatty tumors made up of fat cells. Located under the skin, they are soft to the touch and although they vary in size and shape, the edges of the tumors are well-defined. Lipomas can occur in any dog breed but are most frequently found in older females. Infiltrative lipomas are less common and develop between layers of muscle. More invasive than traditional lipomas, they may also be painful.

  1. Symptoms

    • In general, lipomas are symptomless. There is no pain, except in the occasional case of an infiltrative lipoma, and no loss of appetite or loss of energy that frequently signals other underlying conditions. Because lipomas occur fairly frequently in older dogs, vets advise owners to regularly check their dog for lumps and any type of swelling that is spherical or oval. The most common places to find lipomas are in the chest and abdominal areas.

    Diagnosis

    • Vets have two types of diagnostic tests available. The simplest test is a fine needle aspiration. The vet inserts a needle attached to a syringe into the lump and withdraws a cell sample. The cell sample is put on a glass slide and examined under a microscope for adipose fat cells. If this test doesn't provide conclusive evidence that the lump is a benign tumor, the vet may perform a biopsy to remove a section of the lipoma. This procedure requires either local or general anesthesia.

    Treatment

    • Vets may not treat a small lipoma and instead recommend observing it for signs of change. If it doesn't change, treatment is unnecessary. If the lipoma grows significantly in size and causes the dog discomfort, the vet will remove it. Vets treat infiltrative lipomas aggressively with surgery to remove the tumor as well as an area of tissue around it. If the vet can't completely remove an infiltrative lipoma, they may follow the surgery with a course of radiation therapy.

    Aftercare

    • After any surgical treatment, vets recommend that owners watch their dog carefully for signs of swelling, redness or discharge from the wound. If possible, prevent the dog from licking the wound or chewing at the stitches by putting a plastic "E-collar" on the dog. This is the plastic, cone-shaped collar that fits around the neck and extends over the head. The stitches are usually removed after seven days.