Finding a lump on your dog can be scary. The “Big C” immediately comes to mind: CANCER…. Fortunately, most lumps are not cancerous. Still, they should be taken seriously, especially if they are red, painful, oozing or smelly. Lumps are called papules, nodules, masses, tumors or growths. None of these designations indicate whether the lump is malignant or dangerous.
What Might It Be?
Here are some things that can cause lumps and bumps:
- Abscess. An abscess is an accumulation of pus, usually caused by a bacterial infection. Abscesses are raised and fairly firm. Eventually, most rupture and drain.
- Apocrine Sweat Gland Cyst. These are common, single, smooth, hairless nodules usually filled with liquid and found on a dog’s head, neck or limbs.
- Basal Cell Tumor. Basal cell tumors are single, round, hairless bumps on a stalk or narrow base. They frequently are found on the head, neck, chest and shoulders of older dogs. They are slow-growing and rarely metastasize.
- Bee or Bug Sting. Insect stings can quickly cause swelling, pain, redness, itchiness and quite a big bump at the sting site.
- Ceruminous Gland Adenoma. These benign, small, pink to white-ish growths develop inside the ear canal.
- Fibroma. Fibromas are uncommon, benign tumors that may show up on a dog’s legs, groin or torso.
- Fibrosarcoma. These rapidly-growing tumors can be quite invasive.
- Hemangiosarcoma. Hemangiosarcoma is an invasive, malignant cancer that affects sun-damaged skin and internal areas. It can show up as a blue to reddish dark nodule on the chest or abdomen, and often ulcerates.
- Hematoma (blood blister). Hematomas are localized collections of clotted blood. They are common on the ear tips of dogs with pendulous ears.
- Histiocytoma. Histiocytomas are solitary, rapidly growing, dome-shaped, strawberry-like growths. They usually are benign.
- Injection Site Lump. Some dogs develop a swollen bump at the site of an injection. These can be itchy and red, but rarely are painful.
- Lipoma. Lipomas are soft, roundish, non-painful, fat-filled masses usually located just under the skin.
- Mammary Gland Tumor. Breast cancer unfortunately is common in intact female dogs. Owners will feel lumps under the skin around the mammary glands, often irregular in size and shape.
- Mast Cell Tumor. Mast cell tumors can be solitary or occur in groups. They often are malignant. Boxers, Bulldogs, Boston Terriers and Golden Retrievers are predisposed.
- Melanoma. Most melanomas are brown or black pigmented nodules on areas of dark skin in older dogs. Melanomas in the mouth and nail beds are usually malignant.
- Papilloma (warts). Papillomas are solitary viral growths that aren’t particularly painful or dangerous.
- Perianal Gland Tumor. These benign masses occur around the anus of older intact males.
- Sarcoma. Soft tissue sarcomas can be well-defined or poorly-defined masses on or under the skin. They usually grow slowly.
- Sebaceous Adenoma/Cyst. These are small, smooth, pink, wart-like masses that occur on an older dog’s eyelids or legs. They come from plugged oil glands and are made of dead cells and other debris. Sebacious cysts are common in Cocker Spaniels and Poodles.
- Skin Tag. Skin tags are harmless skin growths that develop as dogs age.
- Squamous Cell Carcinoma. These tumors are gray or reddish, often ulcerated and resemble cauliflowers. They are common but rarely spread.
- Swelling. Lumps caused by swelling are usually associated with puncture wounds and infection. They often are filled with pus.
- Transmissible Venereal Tumor. These cauliflower-like masses can be ulcerated and are found on the genitalia of male and female dogs.
How Do I Figure Out What The Bump Is?
- Impression Smear. Some skin masses can be assessed by pressing a glass slide against them and examining the results under a microscope. The sample can be sent to a pathology laboratory, where it will be dried, stained and examined in great detail.
- Fine-Needle Aspirate. A needle aspirate is taken by inserting a sterile needle into the lump, pulling back on the syringe plunger and squirting the contents onto a glass slide for microscopic examination. The slide can be dried, dyed and sent to a laboratory for detailed assessment. Fine needle aspirates gather cells from an isolated area of the lump. They are not reliably diagnostic.
- Incisional biopsy. This involves surgically removing a small piece of the mass and sending it to a laboratory for evaluation. Sedation and/or anesthesia are necessary when taking biopsies.
- Excisional Biopsy. Sometimes, a dog’s veterinarian will recommend removing the entire lump before a diagnosis is made. This is a good way to eliminate a cosmetic nuisance and remove a potentially dangerous tumor. The tissue will be submitted to a laboratory for evaluation.
- Computed Tomography (CT) Scan. CT scans can help detect internal masses, including those that have metastasized from more superficial sites.
- Radiographs (X-Rays). Radiographs can disclose masses, especially in the lungs.
What Should I Do About This Lump?
- Surgical excision. The cleanest way to deal with lumps is to cut them off. This usually requires general anesthesia and a few sutures.
- Chemotherapy. Drugs designed to target rapidly dividing cells can be highly effective to treat fast-growing tumors. Chemotherapeutic drugs are often used as an adjunct to surgical removal of masses.
- Radiation. Radiation therapy is used to treat invasive tumors that don’t have well-defined borders, and those that are spreading rapidly.