Tumors on Dog Paws

What Are Tumors on Dog Paws?

Tumors can arise anywhere on a dog’s body, and the paws are no exception. Checking a dog’s paws to ensure they don’t have any new masses is an important part of a routine veterinary exam.

Tumors on a dog’s paw typically appear as mass-like growths. They can develop anywhere on the paw, including between the toes, on the paw pads, and at the nail bed.

A variety of tumor types affect dog paws, which means the tumors can have different appearances.

Some paw masses are black, such as a melanoma at the base of a nail bed. Others, like mast cell tumors, can be red or pink, potentially with a raw surface, while some look like warts. Any new growth on your dog’s foot should be examined by a veterinarian.

Common tumors that develop on dogs’ toes or feet and may be cancerous include:

• Melanomas

• Squamous cell carcinomas

• Soft tissue sarcomas

• Mast cell tumors

• Plasma cell tumors

Cancerous tumors are likely to spread to other parts of the body such as the lymph nodes, lungs, or other organs.

However, not all tumors that develop on a dog’s paw fit this category. Your veterinarian will likely collect a sample of cells to examine under the microscope. They may also recommend taking a sample of the mass and sending it to a laboratory for examination by a pathologist.

A growth on your canine companion’s paw may be uncomfortable for them. Some may develop wounds or cause itching, which may lead to a secondary infection.

A growth on your dog’s foot is not an emergency, but you should contact your veterinarian promptly for an appointment. As with all tumors, earlier intervention usually leads to a better outcome than a wait-and-see approach. Your veterinarian is best suited to let you know if the mass can be monitored or needs treatment.

If your veterinarian has recommended that you monitor the mass at home, you should let them know if the mass changes size or color, or if any sores develop.

Symptoms of Tumors on Dog Paws

Symptoms of a tumor on your dog’s paw include:

• A visible growth anywhere on the paw

• Limping

• Excessively licking the foot

• Bleeding or sores on the foot

• Changes to the appearance of a nail, including a nail that splits or falls off

Causes of Tumors on Dog Paws

Most of the time, your veterinarian won’t be able to tell you exactly why your dog developed a tumor on their paw.

Some tumors are assumed to have a genetic component. For example, dogs with black skin may be predisposed to developing melanomas.

Breeds that may be predisposed to melanoma development include:

• Chow Chows

• Doberman Pinschers

• Golden Retrievers

Breeds that are predisposed to mast cell tumors include:

• Boxers

• Boston Terriers

• Golden Retrievers

• Staffordshire Terriers

UV exposure is a known contributor to the development of melanoma in people. Veterinarians assume UV light may play a role in the development of some melanomas in dogs, but the link isn’t as well-established. Dogs also commonly develop melanomas in their mouths, which are unlikely to be caused by sunlight exposure.

How Veterinarians Diagnose Tumors on Dog Paws

Your veterinarian will examine your dog’s paw to determine the next steps. In some cases, they may collect tumor cells with a needle and syringe and examine them under a microscope.

In other cases, your veterinarian may send a sample to an outside lab to find out what kind of tumor your dog has. Paws can be quite sensitive, so your dog may need sedation for this procedure.

Foot X-rays may be performed to see if the nail structure or underlying bone is affected. Your veterinarian may also recommend taking a sample of your dog’s lymph nodes to check for cancer cells if they suspect the tumor is malignant (i.e., cancerous).

Other tests performed in-house may include chest X-rays or an abdominal ultrasound to check for cancer spread, or metastasis.

In some cases, your veterinarian may recommend more advanced imaging—such as a CT scan—to fully evaluate the extent of the tumor and plan for surgical removal. Most veterinarians do not have a CT unit and will need to refer your dog to a specialty clinic for this test.

Treatment of Tumors on Dog Paws

Treatment for your dog’s foot tumor will focus on managing the primary tumor, as well as treating any spread of the cancer.

A tumor on a dog’s paw can be difficult to remove surgically because there isn’t much extra skin to close the surgical incision.

Leg amputation may be recommended for extensive tumors. If only one toe is affected, amputation of the toe may be the treatment of choice. In either case, your veterinarian will recommend sending the tumor to a reference laboratory for evaluation.

The reference lab will determine the tumor type, how aggressive the tumor is, whether there is evidence of spread, and if the entire tumor was removed.

If the tumor is not completely removed, meaning microscopic cells were left behind, your dog may have recurrence of the tumor. Surgery to remove a paw tumor usually takes one to two hours, but may take longer if amputation or reconstruction is necessary. Surgery costs can vary from a few hundred dollars for a small mass removal, to more than a thousand dollars for larger tumors or if limb amputation is needed.

Chemotherapy is recommended for tumors that have spread to other areas of the body or that have a high potential to spread. Chemotherapy can be quite expensive, ranging from $5,000 to more than $11,000, depending on the protocol and how well your dog responds to treatment.

Radiation therapy may be an option for some tumors. This treatment requires traveling to a specialized facility, and your dog must be sedated for each radiation session.

For some mast cell tumors, the injectable medication Stelfonta® may be a treatment option. This treatment works only for tumors under a certain size and has several other restrictions. However, it’s an option to discuss with your veterinarian if your dog’s paw mass turns out to be a mast cell tumor.

Pet parents who cannot afford surgery, chemotherapy, or radiation can still keep their pets comfortable. Therapy may include pain medications like carprofen or gabapentin. In some cases, a soft bootie may prevent injury to the mass.

Recovery and Management of Tumors on Dog Paws

Recovery from most surgical procedures takes around two weeks. Your dog is likely to wear a recovery cone during this time. If your veterinarian has prescribed any antibiotics or pain medications, ensure you give them according to their instructions.

If your dog receives chemotherapy, they will require frequent blood work during treatment. Chemotherapy decreases a dog’s white blood cell count, making it difficult for them to fight infections. Alert your veterinarian to any negative side effects your dog experiences.

Survival time depends on the tumor’s type and severity. This study indicates that most dogs who are diagnosed with a squamous cell carcinoma and undergo toe amputation are still alive one year later, while others say 50% to 83% will survive the first year. The survival rate is lower in the second year.

Another study indicated that survival time for squamous cell carcinoma was 50% at one year and 18% two years after diagnosis and treatment. The same study found that malignant melanoma had a one-year survival rate of 44% and a two-year survival rate of 11%.

Prevention of Tumors on Dog Paws

Most tumors on dog paws are not preventable. Early intervention can provide a better chance for a good outcome, so ensure you check your dog’s paws regularly for any growths or changes.