# Growth on Your Dog's Leg or Foot: When to Get It Checked A dog growth on leg or foot is common, and most turn out to be harmless lumps like cysts, warts, or fatty tumors. But because leg and foot masses can interfere with walking and a minority are malignant, any new lump in these areas deserves a veterinary look. Early evaluation is simple, inexpensive, and gives you a clear plan. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Book a vet visit for any new lump on your dog's leg or foot, even if it looks minor, because these areas are prone to injury and the lump can change how your dog walks. - Ask your veterinarian to perform a fine-needle aspirate at that visit. It is a quick in-clinic test that samples cells from the lump and often gives an answer the same day. - Go to the emergency clinic now if the growth is bleeding heavily, your dog will not bear weight on the leg, or the limb looks swollen, hot, or deformed. - Take a photo with a ruler or coin next to the lump and measure it weekly so you have objective data at your next appointment. - Do not squeeze, poke, or try to remove the lump at home. You can cause bleeding, infection, or spread of abnormal cells. ## What a Growth on a Dog's Leg or Foot Looks Like Lumps on the limbs come in many forms. You may feel a small BB-like bump under the skin, a raised pink or dark nodule on the surface, a soft squishy mass, or a firm lump attached to deeper tissue. Some have hair loss over them. Some are hairless from the start. It helps to know what is normal for your dog. Normal skin should be smooth and even, with no new raised areas. Normal paws have firm, symmetrical pads. Toenails should be even and intact. A little dirt or a healing scrape is fine. A new lump that was not there last month is not normal. Size matters less than change. A pea-sized lump that has been unchanged for two years is usually less concerning than a marble-sized lump that doubled in two weeks. Growth rate is one of the most useful pieces of information you can give your veterinarian. ## Main Causes of a Lump on a Dog's Leg Many different things cause limb lumps. Some are harmless skin growths. Some are infections. Some are cancers. The table below groups the common possibilities, but only a veterinarian can tell you which one your dog has. | Cause | Typical clues | How urgent | |---|---|---| | Wart (papilloma) | Small, cauliflower-like, often on young dogs or around the face and feet | Routine visit | | Sebaceous cyst or follicular cyst | Round, smooth, often with a dark center, may drain cheesy material | Routine visit | | Lipoma (fatty tumor) | Soft, movable, under the skin, slow growing | Routine visit | | Histiocytoma | Rapidly appearing, red, button-like, common in young dogs, often regresses on its own | Visit within a few days | | Abscess or foreign body | Swollen, painful, warm, may drain pus, often after a thorn or bite | Same day | | Mast cell tumor | Variable appearance, may swell or redden when touched, can be itchy | Visit within days | | Soft tissue sarcoma | Firm, deep, often on a limb, may invade bone over time [1] | Visit within days | | Merkel cell carcinoma | Rapidly growing solitary mass, can occur even in young dogs [2] | Visit within days | | Bone tumor (osteosarcoma) | Firm swelling near a joint, pain, lameness, sometimes a pathologic fracture | Emergency or same day | Soft tissue sarcomas are a common canine cancer that can arise on the limbs. In one reported case, a soft tissue sarcoma invaded the humerus (upper arm bone) through a small opening called the nutrient foramen, causing non-weight-bearing lameness in a 7-year-old dachshund [1]. That dog was treated with amputation and did well for 15 months after surgery [1]. This shows why a lump near a bone should not be ignored. Merkel cell carcinoma is a rare but real possibility. A 5-month-old golden retriever developed a solitary, rapidly growing cutaneous mass that was diagnosed as Merkel cell carcinoma after wide surgical removal [2]. Despite being malignant, that dog had no recurrence over at least 20 months of follow-up [2]. Young age does not rule out cancer, and complete surgical removal can be curative. Some lumps are not tumors at all. A foreign body like a grass awn or thorn can create a firm swelling that mimics a growth. An abscess from a bite wound can look like a fast-growing mass. Your veterinarian will consider all of these. ## Red Flags That Make It an Emergency Some signs mean you should stop reading and call an emergency clinic now. - Your dog will not put any weight on the leg at all. - The leg is swollen, hot, and painful to touch. - The lump is bleeding and will not stop. - The lump ruptured and you can see tissue inside. - Your dog is crying, panting, or restless from pain. - The limb looks bent or deformed, which can suggest a fracture through weakened bone. - Your dog is lethargic, not eating, or has a fever along with the lump. Non-weight-bearing lameness was the main sign in the soft tissue sarcoma case described above [1]. If your dog suddenly refuses to use a leg, that is not a wait-and-see situation. For more on lameness timing, see [Dog Limping: When to See a Vet and When to Wait](/knowledge/veterinary-medicine/vet-visit-decisions/dog-limping-when-to-see-vet). ## Safe Things You Can Do at Home While You Wait You cannot diagnose or treat the lump at home, but you can gather information and keep your dog comfortable. **Measure and photograph.** Use a soft tape measure or a ruler next to the lump. Take photos from two angles in good light. Write down the date. Repeat every 3 to 5 days. **Note the texture and attachment.** Is it soft or firm? Does it move freely under the skin or feel stuck to deeper tissue? Is it warm? Does your dog pull away when you touch it? **Prevent licking and chewing.** A dog who licks a lump can irritate it, cause bleeding, or introduce infection. An Elizabethan collar or a soft recovery cone is safe and effective. Do not apply human antibiotic ointments, hydrocortisone, or essential oils unless your veterinarian specifically tells you to. **Limit rough activity.** If your dog is limping, restrict running, jumping, and stairs. Short leash walks for bathroom breaks are fine. For guidance on rest versus vet visits, see [Dog Limping on a Back Leg: When to See a Vet and When to Rest](/knowledge/veterinary-medicine/vet-visit-decisions/dog-limping-back-leg-when-to-see-vet). **Do not give human pain medications.** Ibuprofen, naproxen, acetaminophen, and aspirin can cause serious harm to dogs. Your veterinarian will calculate the correct dose of a safe pain medication based on your dog's weight and health. **Keep a simple log.** Write down when you first noticed the lump, how it has changed, and any changes in your dog's walking, appetite, or energy. This history helps your veterinarian decide what to test. ## What Your Veterinarian Will Check and Test Your veterinarian will start with a full physical exam. They will palpate the lump, measure it, check the nearby lymph nodes, and watch your dog walk. They will also check the rest of the skin for other lumps. ### Fine-Needle Aspirate This is the most important first test. Your veterinarian inserts a thin needle into the lump, collects cells, and examines them under a microscope. It usually takes only a few minutes and most dogs tolerate it well. It can distinguish many benign lumps from malignant ones and guide the next step. Cytology is not perfect. A study of splenic masses in dogs found that cytology and histopathology agreed in only 55% of cases, and disagreement occurred in 24% [3]. When a "possibly neoplastic" cytology result was counted as neoplastic, agreement rose to 67% [3]. This means a fine-needle aspirate is a great starting point, but it does not always give a final answer. If the result is unclear or does not match what your veterinarian feels, they may recommend a biopsy. ### Other Tests Your Vet May Recommend - **Biopsy or surgical removal.** A tissue sample gives a definitive diagnosis and can be curative if the entire mass is removed with clean margins. This was the approach used for the Merkel cell carcinoma puppy, who had no recurrence over at least 20 months [2]. - **Radiographs (X-rays).** These check whether a mass has affected the bone underneath. In the soft tissue sarcoma case, X-rays showed a region of bone destruction in the humerus [1]. - **Blood work and urinalysis.** These assess your dog's overall health before anesthesia or surgery. - **Advanced imaging.** Ultrasound or CT may be recommended for deep masses or to check for spread. Keep in mind that a lump on the leg can sometimes be a sign of a problem elsewhere. A 7-year-old Maltese dog with recurrent hind limb weakness and collapse turned out to have severe hypoglycemia from a liver mass, with a blood glucose of 26 mg/dL [4]. That dog's weakness resolved after the liver mass was removed [4]. Limb weakness is not the same as a limb lump, but it shows that leg signs sometimes point to internal disease. ## Prevention and Monitoring You cannot prevent most skin growths, but you can catch them early. **Do a monthly lump check.** Run your hands over your dog's entire body, including between the toes, on the paw pads, behind the elbows, and along the legs. Feel for new bumps. This takes two minutes. **Track every lump.** Use a body map or a simple notebook. Record the location, size, and date. Bring it to every vet visit. **Keep routine wellness exams.** Your veterinarian will check the skin and limbs at each annual or semiannual visit. Senior dogs benefit from twice-yearly exams. **Protect the paws.** Keep nails trimmed and check pads after walks on hot pavement or rough terrain. Paw injuries can create swelling that looks like a growth. **Spay or neuter as recommended.** Some tumors are hormone-related. Your veterinarian can advise you based on your dog's age, breed, and health. **Know your dog's breed risks.** Some breeds have higher rates of certain cancers. Your veterinarian can tailor monitoring if your dog is at higher risk. ## Limitations and When to Contact a Veterinarian No article can tell you whether your dog's lump is benign or malignant. That requires a hands-on exam and usually a fine-needle aspirate or biopsy. Individual cases need a veterinarian who can see, feel, and test the lump. **Call an emergency clinic now if:** - Your dog cannot bear weight on the leg at all. - The lump is bleeding heavily or will not stop bleeding. - The leg is swollen, hot, and your dog is in obvious pain. - The limb looks deformed or bent. - Your dog is collapsed, weak, or unresponsive. **Call your veterinarian the same day if:** - The lump appeared suddenly and is growing fast. - The lump is red, warm, or draining. - Your dog started limping after you noticed the lump. - Your dog is licking or chewing at the lump constantly. - Your dog has a fever, is not eating, or seems depressed. **Book a routine visit within a week or two if:** - You found a new lump that is not painful and your dog is walking normally. - An existing lump has changed in size, shape, or color. - You are not sure whether a lump is new. For limping that comes and goes, see [Dog Limping Front Leg How Long To Wait](/knowledge/veterinary-medicine/symptom-guides/dog-limping-front-leg-how-long-to-wait). For a red, moist, irritated area on the leg that might be a hot spot instead of a tumor, see [Dog Hot Spot on Leg: How to Treat and When to See a Vet](/knowledge/veterinary-medicine/skin-allergy-and-ear-care/dog-hot-spot-on-leg-treatment). ## Frequently Asked Questions ### Is a growth on my dog's leg always cancer? No. Most lumps on dog legs are benign, including warts, cysts, and fatty tumors. However, some malignant tumors like soft tissue sarcomas and mast cell tumors can occur on the limbs, so every new lump should be checked. A fine-needle aspirate is the quickest way to get an answer. ### Can a leg lump cause my dog to limp? Yes. A lump can cause limping if it is painful, if it presses on a nerve or joint, or if it has invaded bone. In one case, a soft tissue sarcoma invaded the humerus and caused non-weight-bearing lameness [1]. Any limp that lasts more than a day or two should be evaluated. ### Should I wait and see if the lump goes away on its own? Only if your veterinarian tells you to wait. Some lumps, like histiocytomas in young dogs, can regress on their own. Others will not. Waiting too long on a malignant tumor can allow it to grow, invade deeper tissue, or spread. A single vet visit gives you a clear answer. ### What is a fine-needle aspirate, and does it hurt? A fine-needle aspirate uses a thin needle to collect cells from the lump for microscopic examination. Most dogs tolerate it with minimal discomfort, and it usually takes only a few minutes. It is not a definitive test for every lump, but it often provides enough information to guide treatment. ### Can I just have the lump removed without testing it first? Surgery without a diagnosis is possible, but it is not ideal. Knowing the type of lump helps your veterinarian plan how wide the margins need to be and whether other tests are needed first. In some cases, a biopsy or aspirate is done before surgery to guide the approach. Talk with your veterinarian about the best plan for your dog. ## Related Articles - [Dog Limping on a Back Leg: When to See a Vet and When to Rest](/knowledge/veterinary-medicine/vet-visit-decisions/dog-limping-back-leg-when-to-see-vet) - [Dog Hot Spot on Leg: How to Treat and When to See a Vet](/knowledge/veterinary-medicine/skin-allergy-and-ear-care/dog-hot-spot-on-leg-treatment) - [Dog Limping Front Leg How Long To Wait](/knowledge/veterinary-medicine/symptom-guides/dog-limping-front-leg-how-long-to-wait) - [Dog Limping: When to See a Vet and When to Wait](/knowledge/veterinary-medicine/vet-visit-decisions/dog-limping-when-to-see-vet) - [Puppy Limping: When to See a Vet and When to Wait](/knowledge/veterinary-medicine/vet-visit-decisions/puppy-limping-when-to-see-vet) - [Dog Limping Front Leg After Getting Up](/knowledge/veterinary-medicine/symptom-guides/dog-limping-front-leg-after-getting-up) - [Bump on Your Dog's Leg or Foot: Causes and When to Worry](/knowledge/veterinary-medicine/skin-allergy-and-ear-care/dog-bump-on-leg-foot) - [Lump on Your Dog's Leg, Knee, or Ankle](/knowledge/veterinary-medicine/symptom-guides/dog-leg-knee-lump) - [Lumps and Growths on Your Dog's Paw: What They Mean](/knowledge/veterinary-medicine/symptom-guides/dog-paw-growth-lump-causes) ## References 1. [Soft tissue sarcoma invasion of the humerus via the nutrient foramen in a dog](https://pubmed.ncbi.nlm.nih.gov/42699814/). The Canadian veterinary journal = La revue veterinaire canadienne, 2026. 2. [Diagnosis and treatment of Merkel cell carcinoma in a puppy: A comparative oncology approach](https://pubmed.ncbi.nlm.nih.gov/42266333/). The Canadian veterinary journal = La revue veterinaire canadienne, 2026. 3. [Cytology and histopathology have poor to fair agreement for determination of neoplastic or nonneoplastic lesions in dogs with splenic masses or nodules](https://pubmed.ncbi.nlm.nih.gov/42055026/). Journal of the American Veterinary Medical Association, 2026. 4. [Resolution of Recurrent Severe Hypoglycemia After Surgical Excision of a Primary Hepatic Neoplasm of Uncertain Histogenesis in a Dog: A Case Report](https://pubmed.ncbi.nlm.nih.gov/42655842/). Veterinary sciences, 2026. ## Further Reading - [Merck Veterinary Manual: Dog Owners](https://www.merckvetmanual.com/dog-owners) - [Cornell Richard P. Riney Canine Health Center: Canine Health Information](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information) - [American Veterinary Medical Association: Pet Care](https://www.avma.org/resources-tools/pet-owners/petcare)