Digital Tumors in Dogs

Bumps and growths that are found on a dog’s foot may appear non-threatening, but the most common tumors that are found on the digits have a relatively high rate of malignancy and should be evaluated by a veterinary professional as quickly as possible.

Although some growths on the toe may be fairly benign, the majority will require aggressive surgical intervention. Radiation therapy and chemotherapy may also be employed to counteract the cancers, but to date, they have shown only a modest benefit.

Digital tumors, or tumors that occur on or between the toes can be very uncomfortable to the canine, and in some cases, they may be malignant with a high spread rate. This condition requires prompt veterinary evaluation.

There are several signs that may indicate that your dog has developed growths on their toes or under their nail beds. Some of these symptoms may include:

• Broken nail 
• Enlarged lymph nodes
• Excessive grooming of feet
• Lameness
• Pain when touched
• Reluctance to walk or rise
• Solid raised mass on toe
• Swollen toe or foot
• Ulcer on toe

Types

The two most common types of tumor to affect the canine toe include malignant melanomas and squamous cell carcinoma. Squamous cell carcinomas are the most common type of tumor to grow on the canine digits and are more frequently found on larger breed dark-coated dogs and affect female dogs slightly more often than males. Malignant melanomas that are found on the toes are somewhat less prevalent than squamous cell carcinomas, but they can be much more likely to spread to other organs, particularly the lungs. Tumors that are found on the toe should be addressed as quickly as possible as they frequently spread to other organs.

The causes and trigger for most cancers and tumors are not well understood, however, certain characteristics may increase the chances that a growth may develop. Darkly pigmented, large breed dogs are more likely than others to obtain these tumors, and they are more likely to develop in dogs that are in excess of nine years old. Certain breeds may also be predisposed to acquiring digital tumors, including: 

• Basset Hounds
• Beagles
• Bloodhounds
• Briards
• Bull Terriers
• Dalmatians
• Giant Schnauzer
• Gordon Setters
• Kerry Blue Terriers
• Labrador Retriever
• Schnauzers 
• Standard Poodle

When you bring your dog into the veterinary clinic in regards to a growth or growths on the toe on underneath the toenail bed, your veterinarian is likely to start by conducting a full physical examination, checking carefully all over the body to see if any other growths are present. The lymph nodes will also be palpated during the evaluation to see if there is swelling and standard diagnostic blood tests like a complete blood count and biochemical profile may show a greater than average quantity of white blood cells. 

A biopsy of the cells found in the tumors will help the technician determine whether or not the cells are cancerous and which type of cancer is involved, and x-ray imaging will typically be employed to establish if the bones of the foot have been affected and to what extent. A sample of the fluid found in the lymph nodes will also be evaluated to ascertain if any cancer cells have spread to these glands.

The primary treatment for either squamous cell carcinomas or malignant melanomas that are found on the toe or in the nail bed is the complete removal of the tumor as well as the removal of a wide margin of tissue around the growth. In the majority of cases, the excision of the entire toe that the growth is found on is recommended to prevent the spread of the disease. This is more likely to be a successful treatment plan for squamous cell carcinomas as they are not as quick to spread as malignant melanomas. 

Although traditional cancer treatments such as radiation and chemotherapy show only a modest benefit in counteracting these types of cancer, a DNA vaccine that has been developed to fight malignant melanomas of the mouth has shown promise for these types of growths that develop on the toe as well. Anti-inflammatory medications and antibiotic will also typically be prescribed after the operation to help prevent infections and to ease the pain and swelling associated with the condition and treatment.

After any surgery, it is essential to keep the site clean and free from dirt and debris. You will need to keep your pet from interfering with the site and examine it often over the next two or three weeks for swelling, bleeding or pus. Keeping the recovering patient in a calm, quiet environment will help encourage healing, as will having sufficient quantities of fresh food and water within their reach. Specialized care instructions may be given by your veterinarian about changing the bandages and administering medications to facilitate healing. If the cancer has spread, the dog may require repeated visits to complete treatments like radiation therapy and chemotherapy.