Dear friends of the Riney Canine Health Center,
Have you ever found a skin lump on your dog and felt like it suddenly appeared overnight? Skin tumors and lumps in the layer underneath the skin (subcutaneous layer) are very common in dogs. Many can be malignant, which could spread to other parts of the body, including mast cell tumors and soft tissue sarcomas. Skin tumors can also be benign, including lipomas, histiocytomas, sebaceous gland adenomas, and more. While some masses may have a characteristic look, feel, or location on the body, there is no way to know with 100% certainty what a mass is just by looking at it.
Two common diagnostic tests for skin tumors include a fine needle aspirate, and a biopsy. A fine needle aspirate, or an FNA, is a non-invasive test performed using a small gauge needle to “poke” the skin mass, collect tumor cells, and evaluate them under the microscope. A biopsy removes the entire segment of skin tissue involving the mass, most often when a pet is under general anesthesia.
When tumors are monitored for too long without any testing, masses can grow to a size that may later require more invasive surgery. Malignant tumors often require wide skin margins around the mass. Tumor cells can unintentionally be left behind if a mass grows too large in an area on the body with less healthy skin surrounding the mass, such as a limb or around the face. The mass could regrow if this occurs, leading to more aggressive and expensive procedures. If the mass is large or in a difficult body location to perform surgery, your veterinarian may refer you to a veterinary cancer specialist.
If you find a skin mass on your dog, use the following parameters as indicators to schedule an appointment with your veterinarian if one or more of the following applies. The mass is:
If a skin tumor is found early when it is still small, surgical removal alone may cure them of the disease with no other treatments necessary. This is often true if it is a benign (non-cancerous) tumor, which only invades the nearby tissues and does not involve other parts of the body (metastasis). Some benign tumors might not need removal if they are relatively small and on an area of the body not likely to cause issues. Alternatively, a benign mass may be removed if it is in a tricky location, growing in a spot that would create a more complicated surgery or if it is causing discomfort.
By incorporating routine checks for lumps and bumps into your dog's preventative healthcare, you take a proactive approach to their well-being by catching potential issues before they become more significant.
As always, thank you for being a Riney Canine Health Center member. We look forward to catching up with you next month!
Dr. Aly Cohen
Extension veterinarian
Cornell Richard P. Riney Canine Health Center