Type

• Subungual squamous cell carcinoma is a cancer that occurs on the dog's digits, or toes. According to the Canine Cancer website, it is the "most frequently diagnosed carcinomas arising in the skin in dogs." More than 50 percent of all tumors on the toes are squamous cell carcinoma, as stated by the Michigan Veterinary Specialists website.
  
  

Symptoms

• Aside from a tumor on one of the dog's toes, you may notice swelling or loss of a toenail. Other symptoms may include weight loss, coughing, lack of appetite, lethargy or having trouble breathing.
  
  

Treatment

• Amputation of the infected toe is necessary if the tumor is malignant. Chemotherapy and radiation are also administered to rid the dog of any remaining cancer. It is important to limit the dog's sun exposure to prevent a relapse.