Foot or Toe Cancer in Cats

When a cat presents with unexplained lumps or lesions, a veterinary examination is recommended. If the symptoms are linked to the presence of cancer, early diagnosis and proper treatment are critical to the likelihood of survival.

The presence a tumor on the nail bed is a rare condition in cats. More commonly, tumors appear on the feet after having metastasized from other areas of the body. The two most common types of tumors found on the foot are squamous cell carcinoma (SCC) and melanocytic tumors.

Squamous cell carcinoma affects the cells that create the lining of the inner cavities of the body and outermost layer of the skin, known as the epithelium. SCC is often malignant and invasive. There is a high chance that it will return after removal and is likely to metastasize to other parts of the body. The cancer progresses slowly, increasing the chance of a positive outcome if found early. Unfortunately, by the time tumors appear on the feet they have often already spread from other areas of the body.

Melanocytic tumors develop from the cells responsible for producing pigment (melanocytes) and melanin (melanoblasts). The tumors may present as spots, patches, masses that are either flat or raised. The tumors may be either benign or cancerous.

When tumors are present in the nail bed, it is likely that the affected nail will be broken or missing. The nail bed is often infected and the bone may have deteriorated. Nail bed tumors are often misdiagnosed as osteomyelitis (bone inflammation) or a simple nail infection. Severe weight loss is also common due to both a lack of appetite and changes to the metabolism related to the presence of cancer.

Squamous cell carcinoma often starts off as a small lump (nodule) or a blister-like lesion (papule). As it progresses, it grows and loses its mass-like shape. Eventually, the tissue begins to die (necrotize) and tumor ulcerates. Additional symptoms of SCC include:

• Swelling of feet or toes
• Limping
• Bleeding sores on toes 
• Sores or tumors on other body parts

Melanocytic tumors are most commonly found on the head, ears, nose and toes. Symptoms of this condition include:

• Lesions (with or without pigment)
• Enlarged lymph nodes
• Difficulty breathing
• Lung cancer 
• Limping (if spread to limbs)

Squamous cell carcinoma is rarely found on the feet of cats unless it has metastasized from other body parts. It can affect cats of any breed or age. 

Melanocytic tumors are most common in cats between eight and 14 years of age. No known cause has been identified.

Prior to completing a physical exam, the treating veterinarian will review the cat’s medical history. Owners should discuss with the vet any sores or lumps that have been noticed previously, even if they are thought to have been caused by other circumstances. 

The vet will examine the cat’s entire body to look for additional sores and tumors, and will check lymph nodes for swelling. A standard set of lab tests will likely be ordered. A biochemistry profile may be used to check the levels of white blood cells and confirm whether bodily organs are functioning correctly. Chest x-rays will identify any lung abnormalities, and x-rays of the affected foot will help to determine the depth of the tumor and the extent of bone damage. Each ulcer or mass on the body should be tested using either a fine-needle aspiration or a tissue biopsy to determine whether cancerous cells are present.

Treatment recommendations will vary depending on the number and severity of the tumors and whether they have metastasized. 

Single Tumor

When a tumor is present on only one toe, surgery is recommended. A full amputation of the toe will provide the best prognosis for a full recovery without recurrence. Cats quickly adapt to the loss of a toe and are usually able to walk normally once they have recovered.

Multiple Tumors

When multiple tumors are present, surgery may not be a viable option. The veterinarian will likely prescribe pain medications to keep the cat comfortable and may recommend a consultation with a veterinary oncologist to discuss further options.

Melanocytic Tumors

For melanocytic tumors, surgery is the primary treatment recommendation. If the tumors are benign, the outlook for affected cats is very positive. If surgery is not an option or the tumor has spread to other areas of the body, radiation or chemotherapy may be recommended.

When a toe has been removed, cats will usually experience limping and mild pain immediately following surgery. This can be controlled with medication and will subside as the foot heals. The cat should be kept indoors and activity should be limited until it has fully recovered. If the tumor has not metastasized, the prognosis for recovery is very positive.

It’s common for cats with cancer to experience ongoing pain. Owners should carefully observe the animal for signs of distress and proactively manage pain whenever possible. Proper nutrition is also critical for the cat to maintain the strength it needs to recover. It should be fed a high-quality, balanced diet. If the cat refuses to eat or displays other symptoms that may indicate that the cancer has returned, an immediate trip to the vet is recommended. 

As is the case with most tumors, the chance of recurrence depends on the type of tumor. Depending on the veterinarian’s recommendation, the pet may need to be re-examined every three to 24 months.