Common Lumps and Bumps on Pets

Veterinarian doing a check-up on a Corgi in clinic

Ron Levine / Getty Images

Pets can develop lumps and bumps on practically any part of their body and while some are definitely cause for concern, others may be purely a cosmetic change. It's helpful for a pet owner to know the different kinds of skin lumps they may see and how they are treated. This way they can better help their pets get the veterinary care they need when it's necessary.

  • 01 of 04

    Lipomas (Fatty Tumors)

    Lipoma on dog's neck prepped for surgical removal

    Janet Tobiassen Crosby DVM

    Also referred to as adipose tumors and lipomas, fatty tumors are extremely common in many pets, especially dogs. These lumps are often described as soft and moveable and are just under the skin but should not be ulcerated or oozing. They are benign bumps so they are not usually a cause for concern. They can grow quite large and appear almost anywhere. Unless they are making it difficult for your pet to walk or run normally, these lumps under the skin are non-cancerous and therefore your veterinarian may not deem them necessary to be removed.

    In order to definitively diagnose your pet with a lipoma and ensure it is not another type of bump, a sample of the lump may be taken by your veterinarian using a needle. This does not usually require sedation but if a biopsy needs to be obtained, your pet may need to be sedated or anesthetized. Surgery to remove the lump may be recommended if the diagnostic tests are inconclusive or if the lump gets in the way of your pet's normal movements.

  • 02 of 04

    Histiocytomas and Mast Cell Tumors

    Histiocytoma on pink skin

    Lianne McLeod / The Spruce

    Histiocytomas and mast cell tumors look very similar but cause different levels of concern. Both of these types of lumps are on the skin surface and are often described as being red, raised, and circular. They often appear on the legs but can pop up on other parts of the body, too. These lumps should not be squeezed in case they are mast cells, a cancerous type of growth that can spread.

    In order to determine whether your pet has a histiocytoma or a mast cell tumor, you can either wait and see if it goes away or have it surgically removed by your veterinarian and sent to a lab. Waiting can be dangerous if it is a mast cell as this gives it time to grow and spread but if it is a histiocytoma, it will disappear over time. If it is a mast cell, the laboratory will assign it a grade and state whether or not all of the cells were removed during the surgery. Grade I mast cells are benign and typically surgery is curative but grade II and III mast cell tumors can spread. The laboratory report will determine what the next steps for your pet are if it has a mast cell tumor but a second surgery and chemotherapy may be recommended.

  • 03 of 04


    Lab and orange cat cuddling together.
    Dogs and cats shouldn't share everything.

    Getty Images/GK Hart/Vikki Hart

    Perianal gland adenomas are some the most common types of adenomas in pets and occur around the anal opening. They may also be called circumanal adenomas or hepatoid adenomas and are benign lumps. Perianal gland adenomas are usually slow-growing and on the surface of the skin next to the anus. Surgery may or may not be recommended depending on how close they are to the anus and whether or not they are regularly bleeding or getting infected.

    Sebaceous gland adenomas are also almost always benign and appear as wart-like structures or skin tags on a pet's body. These are very common and do not usually require surgery but are sometimes removed if they regularly bleed or get in the way of grooming. Cryosurgery may be utilized for these small adenomas which results in freezing the wart and then allowing it to fall off at home when the tissue dies.

  • 04 of 04

    Sarcomas and Carcinomas

    Skin cancer on a dog
    A lump is the most obvious sign of skin cancer on a dog.

    Getty Images/Elen11


    Cancerous growths are the most concerning types of lumps and bumps. There are several different types of sarcomas and carcinomas but they are all malignant and all therefore considered to be cancerous. Basal cell carcinomas (not to be confused with non-carcinoma basal cell tumors), fibrosarcomas, sebaceous gland adenomarcinomas (not to be confused with benign sebaceous gland adenomas), squamous cell carcinomas and others are serious lumps and bumps seen on pets. These lumps will typically be surgically removed and chemotherapy may be recommended.

Many other kinds of lumps and bumps including various cysts, abscesses, papillomas, melanomas, and more can also occur on pets. Due to the numerous types of growths that can appear, it is always best to get your pet checked out by a veterinarian to determine what type of lump is present. Not all lumps are bad news but you should make sure that's the case before assuming a lump can be ignored.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.