Dear Dr. Thompson: My 10-year-old Australian shepherd had a swollen front toe about three weeks ago. The veterinarian put him on antibiotics for two weeks and warned me if the swelling did not get better we would need to take X-rays. It didn’t change much and we took X-rays and the vet is worried it might be cancer and said the toe should be amputated and biopsied. Is there another way to determine if this swelling is cancerous and how he will do without the toe?
Unfortunately growths on the very last part of the toe and nail can be particularly nasty. Many times they involve the skin and underlying bone of the third digit. These can often look like an infected toe that does not heal with antibiotic therapy. A characteristic appearance on X-rays is that the bone of the third digit will appear eroded away by the cancer.
While it seems drastic, the best way to get an accurate diagnosis and solve this problem is by amputating the toe and sending it to a pathologist for evaluation. Collecting cells with a needle or a smaller biopsy sample has too many chances at a misdiagnosis. Most of these growths are cancerous, and failing to aggressively treat the primary tumor can have disastrous consequences.
A few tests are needed prior to surgery to make sure he is a good candidate and ensure there is no evidence the cancer has spread. Chest X-rays are a simple way to look for tumors that may have spread throughout the body. They are not foolproof, but if obvious tumors are present, surgery would not be in his best interest. Collecting cells from the lymph nodes that are above the affected toe may reveal cancerous cells that would warrant a more aggressive treatment strategy.
The two most common cancers are melanoma and squamous cell carcinoma. Both are locally aggressive and have varying potential to metastasize or spread to distant sites. Fortunately, with early detection and early surgical treatment, cure rates are quite high. The other good news is that dogs do extremely well after surgery. Depending on what toe is affected, the cosmetics are excellent and dogs accommodate to the new mechanics of walking on three toes almost immediately. It may take a couple weeks to get the biopsy results back, but hopefully you will get good news and I am sure he will do fine.
Questions for Dr. Gary Thompson can be emailed to firstname.lastname@example.org or mailed to The Blade, Attn. Ask the Vet, 541 N. Superior St., Toledo, OH 43660. Dr. Thompson regrets that he cannot answer individual letters.