# Paw Tumors in Dogs: Signs, Types, and Treatment A dog tumor on paw is any abnormal lump or growth on the foot, toes, or paw pad. Some are harmless cysts or warts, while others are cancers that need prompt treatment. Because paws take a beating every day, even small masses can cause limping, licking, or bleeding. This article is educational and is not a substitute for veterinary diagnosis or treatment. ## Quick Answer - Any new lump, swelling, or sore on your dog's paw deserves a veterinary exam, even if it looks small. - Tumors on the paw are less common than tumors on the trunk, but they are often found later because owners do not check feet often. - Mast cell tumors, soft tissue sarcomas, and bone tumors are among the types that can affect the paw or the bones of the leg. - A biopsy (tissue sample sent to a lab) is the only way to know for sure whether a mass is cancer. - Surgery is the most common treatment, and the lab checks the removed tissue to see whether the whole tumor came out. ## What Is a Dog Tumor on Paw? A tumor is an abnormal growth of cells [1]. Tumors that affect the skin or the tissue just under the skin are the most commonly seen tumors in dogs [1]. When one of these growths appears on a paw, toe, or paw pad, owners often notice it because the dog starts limping or licking the area. Paw tumors can start in the skin, in the tissue beneath the skin, in the nail bed, or in the bone itself. Some are benign (noncancerous) and grow slowly without spreading. Others are malignant (cancerous) and can invade nearby tissue or spread to other parts of the body. The paw is a tough place for a tumor. The tissue there is tight, and every step puts pressure on the growth. That is why even a small mass on a paw can cause more obvious signs than a similar lump on the back or flank. ## Signs of a Dog Tumor on Foot or Paw Owners often spot paw problems because the dog changes how it walks. Watch for these signs: - A visible lump, bump, or swelling on the paw, toe, or pad - Limping or favoring one leg - Licking or chewing at one spot on the foot - Bleeding from the paw or a sore that will not heal - A toenail that is loose, crooked, or falling off - Swelling that feels firm or warm - Reluctance to walk, run, or climb stairs Lameness in a front leg can come from many causes, including orthopedic, neurologic, and neoplastic (tumor) disorders, and the signs often overlap [2]. That is why a veterinarian needs to examine your dog instead of guess from a photo or description. Some paw tumors look like minor injuries at first. A small red bump or a swollen toe can be mistaken for a bug bite, a splinter, or a torn nail. If a paw sore does not improve within a few days, or if it keeps coming back, ask your veterinarian to look at it. If your dog is constantly licking one paw, that behavior alone is a reason to get it checked. Licking can be a sign of pain, itching, or a mass under the skin. Our article on [Dog Licking Paws Cancer](/knowledge/veterinary-medicine/clinical-methods/dog-licking-paws-cancer) explains when this habit points to something more serious. ## Common Types of Tumors on Dog Paws Several tumor types can appear on or near the paw. The list below covers the ones veterinarians see most often. ### Mast Cell Tumors Mast cell tumors are a common skin tumor in dogs. They can show up as a raised lump, a flat patch, or a sore that looks like an insect bite. Some are benign and some are aggressive, and the only way to tell is through lab testing. Mast cell tumors have been described across domestic mammals, and diagnosis relies on examining the tissue under a microscope along with special staining techniques [3]. ### Soft Tissue Sarcomas Soft tissue sarcomas are malignant tumors that affect the body's connective tissues [4]. They are common in dogs, especially in medium to large breeds and older animals [4]. These tumors have poorly defined margins, which makes them invasive and prone to growing back after surgery [4]. They spread to other parts of the body at low rates and respond poorly to chemotherapy [4]. Soft tissue sarcomas can also invade bone. In one reported case, a soft tissue sarcoma in a dog's upper front leg grew into the humerus bone through a small opening called the nutrient foramen [5]. That dog had the leg amputated and maintained a good quality of life for 15 months after surgery [5]. ### Bone Tumors (Osteosarcoma) Bone tumors are much less common in cats than in dogs, and in dogs they most often affect the distal radius, proximal humerus, distal femur, or proximal tibia [6]. Osteosarcoma is the most common primary bone tumor, accounting for over 80% of bone tumors in dogs [6]. Osteosarcoma is often diagnosed in large or giant breed dogs such as Rottweilers, Great Danes, St. Bernards, and Golden Retrievers [7]. It commonly grows on the long bones of the forelimbs or hindlimbs, causing pain and lameness [7]. This tumor is aggressive and often spreads to the lungs early in the disease [7]. It is more common in older dogs around seven years of age, though a small subset of dogs may develop it as young adolescents [7]. ### Squamous Cell Carcinoma Squamous cell carcinoma is a cancer that starts in the flat cells of the skin and mouth. It can appear on the toes and nail beds. One report described a rare subtype called canine oral papillary squamous cell carcinoma in a young dog, which was treated with surgery and chemotherapy and had no recurrence or spread more than 1,400 days later [8]. That case involved the mouth, but it shows that squamous cell cancers vary widely in behavior and that treatment outcomes depend on the specific type. ### Other Growths Not every lump is cancer. Warts, cysts, and benign skin growths are common. If you are trying to decide whether a growth is harmless, our guide [Dog Skin Tag or Tumor? How to Tell and What to Do](/knowledge/veterinary-medicine/skin-allergy-and-ear-care/dog-skin-tag-or-tumor) walks through the differences. | Tumor Type | Where It Appears | Typical Behavior | |---|---|---| | Mast cell tumor | Skin, often on limbs | Can be benign or aggressive | | Soft tissue sarcoma | Connective tissue under the skin | Locally invasive, low spread rate [4] | | Osteosarcoma | Long bones of legs | Aggressive, spreads early [7] | | Squamous cell carcinoma | Skin, toes, nail bed, mouth | Varies by subtype | | Benign growths (warts, cysts) | Skin surface | Slow growing, does not spread | ## Causes and Risk Factors The exact cause of most paw tumors is not known. In general, skin tumors can be triggered by chemicals, solar radiation, and viruses, and hormonal abnormalities and genetic factors may also play a role [1]. For osteosarcoma, the exact cause is unknown, but there is likely a genetic component given the predisposition in certain large breeds [7]. Age matters too. Osteosarcoma is more common in older dogs around seven years of age, though some young dogs develop it [7]. Soft tissue sarcomas are more common in medium to large breeds and older animals [4]. Some tumors have no clear trigger at all. If your dog develops a paw mass, do not blame yourself or assume you missed something. Many of these growths arise without any obvious cause. ## How Veterinarians Diagnose a Paw Tumor Diagnosis starts with a physical exam. Your veterinarian will feel the mass, check its size and texture, and examine the whole leg. They may also watch your dog walk to see how the limb is used. ### Fine Needle Aspirate A fine needle aspirate is often the first test. The veterinarian inserts a thin needle into the mass, collects cells, and examines them under a microscope. This is quick and usually well tolerated. It can identify some tumors, such as mast cell tumors, but it does not always give a full answer. ### Biopsy A biopsy removes a piece of tissue for lab analysis. This is the most reliable way to identify the tumor type. After surgical removal, tumors should be evaluated under a microscope to confirm the type and whether all of the tumor was likely removed [1]. The lab checks the edges of the removed tissue, called margins [1]. Dirty margins mean tumor cells reach the edge of the sample, so some cancer likely remains [1]. Narrow margins mean cells are close to the edge but not at it, so some cells could be left behind [1]. Wide or clean margins mean cells are far from the edge, so it is unlikely any tumor remains [1]. ### Imaging X-rays can show whether a tumor has affected the bone. If a bone tumor is suspected, your veterinarian will likely recommend chest X-rays to check for spread to the lungs, since osteosarcoma often metastasizes there early [7]. Advanced imaging such as CT or MRI may be used for complex cases, and referral is common when the diagnosis is unclear [2]. ## Treatment Options for Dog Tumors on Paws Treatment depends on the tumor type, size, location, and whether it has spread. ### Surgery Surgery is the most common treatment for paw tumors. The goal is to remove the entire mass with clean margins [1]. For small tumors on the skin, this may be a simple excision. For tumors involving a toe or nail bed, removing the affected toe is sometimes needed. For bone tumors, amputation of the limb may be recommended [6]. ### Chemotherapy Chemotherapy is used for tumors that have spread or are likely to spread. For malignant bone tumors, treatment can include surgical intervention such as limb amputation, chemotherapy with carboplatin, cisplatin, or doxorubicin, and sometimes radiation therapy [6]. Your veterinarian calculates the dose based on your dog's weight and health. Soft tissue sarcomas respond poorly to chemotherapy, so surgery is usually the main treatment [4]. ### Radiation Therapy Radiation can be used to shrink tumors before surgery or to relieve pain when surgery is not possible. For bone tumors, radiation therapy can also be part of palliative care to decrease pain and discomfort [6]. ### Pain Management Palliative care for bone tumors can include oral NSAIDs, opioids, or radiation therapy to reduce pain [6]. Pain control matters at every stage, whether your dog is being treated with curative intent or receiving comfort-focused care. ## Recovery, Outlook, and Long-Term Management Recovery depends on the tumor type and the treatment used. After surgery, most dogs need rest and a bandage or splint for a period your veterinarian will set. You will need to keep the incision clean and watch for swelling, discharge, or changes in behavior. Outlook varies widely. Benign tumors removed with clean margins often do not come back. Malignant tumors carry a higher risk of recurrence. Soft tissue sarcomas are locally invasive, and local recurrence is a major clinical challenge [9]. In one study of dogs with soft tissue sarcoma that recurred after surgery, the median time to recurrence was 358 days [9]. For osteosarcoma, there is no cure, but treatment options can help delay the progression of the disease and alleviate pain [7]. Some dogs live comfortably for months after amputation and chemotherapy. Others do better with pain-focused care. Long-term management often means regular checkups, periodic imaging, and watching for new lumps anywhere on the body. Check your dog's paws monthly, especially between the toes and around the nails. Early detection gives you more options. ## Prevention There is no sure way to prevent paw tumors. You can lower some risks by limiting sun exposure on light-colored or thin-haired areas, avoiding known chemical exposures, and keeping up with routine veterinary visits [1]. The most practical prevention is early detection. Feel your dog's paws regularly. Look between the toes, check the pads, and inspect each nail. If you find a lump, note its size and take a photo with a ruler or coin next to it. Bring that information to your veterinarian. If your dog has allergies or infections that cause paw licking, treating those conditions can reduce chronic inflammation. Our articles on [Dog Paw Allergies: Signs, Causes, and Treatment](/knowledge/veterinary-medicine/preventive-care/dog-paw-allergies) and [Dog Nail Infection: Signs, Causes, and Treatment](/knowledge/veterinary-medicine/preventive-care/nail-infection-in-dogs) cover those common problems. A [Swollen Dog Paw: Comprehensive Veterinary Reference Guide](/knowledge/veterinary-medicine/preventive-care/swollen-dog-paw) can also help you sort out swelling from a mass. ## Limitations and When to Contact a Veterinarian No article can tell you whether your dog's paw lump is cancer. Only a veterinarian can examine the tissue and run the tests needed for a diagnosis. Individual cases need a veterinarian. Contact your veterinarian the same day if you notice: - A new lump or swelling on the paw - A sore that bleeds or will not heal - Sudden limping that does not improve after rest - A toenail that is loose or falling off Go to an emergency clinic right away if: - Your dog cannot bear weight on the leg at all - The paw is swollen, hot, and painful - There is heavy bleeding from the paw - Your dog shows signs of severe pain such as crying, pacing, or refusing to be touched Schedule a routine visit soon if: - A paw lump has been present for more than a few days - Your dog licks one paw constantly - You notice a change in the size or color of an existing lump ## Frequently Asked Questions ### Are paw tumors in dogs usually cancer? No, not all paw tumors are cancer. Some are benign cysts, warts, or fatty growths. However, because benign and malignant masses can look alike, a biopsy is the only way to know for sure. ### Can a dog tumor on paw pad be removed without removing the toe? Sometimes. It depends on the size, location, and type of tumor. Small masses on the pad or skin may be removed with a margin of normal tissue while preserving the toe. Larger or invasive tumors may require toe removal to get clean margins. ### Do dog tumors on paws spread to other parts of the body? Some do and some do not. Soft tissue sarcomas spread at low rates but are locally invasive [4]. Osteosarcoma often spreads to the lungs early in the disease [7]. Mast cell tumors vary widely, with some staying local and others spreading. ### How long can a dog live with a paw tumor? It depends on the tumor type, stage, and treatment. One dog with a soft tissue sarcoma that invaded bone lived well for 15 months after amputation [5]. Another dog with a squamous cell carcinoma had no recurrence more than 1,400 days after surgery and chemotherapy [8]. Your veterinarian can give you a more specific outlook after diagnosis. ### Should I wait and see if a paw lump goes away on its own? No. Paw masses rarely resolve on their own, and waiting can allow a tumor to grow or spread. If a lump is still present after a few days, or if your dog is limping or licking the area, book a veterinary visit. ## Related Articles - [Dog Paw Allergies: Signs, Causes, and Treatment](/knowledge/veterinary-medicine/preventive-care/dog-paw-allergies) - [Dog Licking Paws Cancer](/knowledge/veterinary-medicine/clinical-methods/dog-licking-paws-cancer) - [Dog Nail Infection: Signs, Causes, and Treatment](/knowledge/veterinary-medicine/preventive-care/nail-infection-in-dogs) - [Dog Skin Tag or Tumor? How to Tell and What to Do](/knowledge/veterinary-medicine/skin-allergy-and-ear-care/dog-skin-tag-or-tumor) - [Swollen Dog Paw: Comprehensive Veterinary Reference Guide](/knowledge/veterinary-medicine/preventive-care/swollen-dog-paw) - [Mast Cell Tumors in Dogs: Histopathological Grading and Treatment Guide](/knowledge/veterinary-medicine/dermatology-oncology/mast-cell-tumors-in-dogs-histopathological-grading-and-treatment-guide) - [Lump on Your Dog's Paw or Paw Pad](/knowledge/veterinary-medicine/symptom-guides/dog-paw-pad-lump) - [Lumps and Growths on Your Dog's Paw: What They Mean](/knowledge/veterinary-medicine/symptom-guides/dog-paw-growth-lump-causes) - [Melanoma in Dogs' Toes: Signs and Treatment](/knowledge/veterinary-medicine/senior-and-chronic-care/melanoma-dogs-toe) ## References 1. [Tumors of the Skin in Dogs - Dog Owners](https://www.merckvetmanual.com/dog-owners/skin-disorders-of-dogs/tumors-of-the-skin-in-dogs). Merck Veterinary Manual. 2. [Diagnosing Thoracic Limb Lameness in Dogs](https://pubmed.ncbi.nlm.nih.gov/42767891/). The Veterinary clinics of North America. Small animal practice, 2026. 3. [Disseminated cutaneous mast cell tumor in a South American coati (Nasua nasua)](https://pubmed.ncbi.nlm.nih.gov/42536293/). Veterinary research communications, 2026. 4. [Canine cutaneous and subcutaneous soft tissue sarcoma in dogs: a consensus report from the Brazilian association of veterinary oncology](https://pubmed.ncbi.nlm.nih.gov/42182906/). Frontiers in veterinary science, 2026. 5. [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. 6. [Bone Tumors in Dogs and Cats - Musculoskeletal System](https://www.merckvetmanual.com/musculoskeletal-system/osteopathies-in-small-animals/bone-tumors-in-dogs-and-cats). Merck Veterinary Manual. 7. [Osteosarcoma in dogs](https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/osteosarcoma-dogs). Cornell University College of Veterinary Medicine. 8. [Canine oral papillary squamous cell carcinoma with lymph node metastasis in a dog](https://pubmed.ncbi.nlm.nih.gov/41030429/). The Canadian veterinary journal = La revue veterinaire canadienne, 2025. 9. [Assessment of Clinical and Immunological Factors of Local Recurrence in Canine Soft Tissue Sarcoma](https://pubmed.ncbi.nlm.nih.gov/42713725/). Veterinary and comparative oncology, 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)