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What Should You Do if Your Dog Has a Swollen Toe?

Posted February 11, 2015 in Dog Diseases & Conditions A-Z

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Dr. Phil Zeltzman is a traveling, board-certified surgeon in Allentown, PA. His website is He is the co-author of “Walk a Hound, Lose a Pound” (

Zee Mahmood, a veterinary technician in Reading, PA, contributed to this article.

When your dog has a swollen toe, it is easy to underestimate the potential seriousness of this condition. Dog owners can sometimes write it off as a bug bite or something their dog has stepped on. However, the swollen toe can be a sign of something much more serious. Cancerous tumors may initially present themselves as a swollen toe and should be diagnosed and treated as early as possible for a positive outcome.

Swollen toe red flags
A swollen toe can cause limping or reluctance to walk due to pain. Usually, only one toe is affected. [Editor’s Note: If you see your dog limping for any reason, visit the veterinarian.]

Cancerous tumors can be tricky as they may disguise themselves as a broken toenail. The tumor weakens the toenail and causes the nail to snap off without major trauma. Large-breed dogs (Labradors, Standard Poodles) and black-colored dogs are more likely to be affected by such tumors. Tumors of the toe are most commonly (but not always) seen in dogs older than 10 years.

How do veterinarians find the cause of a swollen toe?
After performing a thorough exam and blood work, your family veterinarian may recommend taking a sample of the swelling to check for the presence of cancerous cells. The most important step in the diagnosis of a broken nail is x-rays of the foot, which may reveal bone destruction in the toe. Further x-rays can show if cancer has spread to other body parts, such as the lungs.

How can a swollen toe turn fatal?
All of these diagnostic procedures will help your veterinarian pinpoint what may have caused your dog's swollen toe. A broken toenail may just be a broken toenail, or it may be a sign of something much worse beneath the surface:

  • Your dog's swollen toe may be caused by an infection or a foreign body in the toe, such as a splinter, or more rarely an insect bite or sting.
  • There may be a fracture in the bone of the toe.
  • Most cancerous tumors, such as melanoma and squamous cell carcinoma, occur at the junction between the toenail and the toe.
  • A small lump may just be a wart or blister, but a similar appearing nodule could very well be squamous cell carcinoma. Squamous cell carcinoma is the most common type of tumor to affect a dog's toe. There is no known cause.
  • Melanoma is the same disease known as skin cancer in humans, most often a result of excessive sun exposure. Although it is not known what causes this disease in dogs, it is malignant and spreads quickly to other parts of the body including the lungs.
  • Less common cancers occur in the bone (osteosarcoma) or the cartilage (chondrosarcoma) of the toe.
  • Any of these conditions may present itself as a swollen toe, making it even more important to see your veterinarian early so that an appropriate treatment plan can follow.
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Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his website at, and follow him at