Just like people, pets can get cancer. Pet parents are usually the first to detect a small bump on their pet’s skin, and most people make an appointment with their veterinarian immediately to have it evaluated. Before you hit the panic button, however, I want to let you know that even if the bump turns out to be cancerous, you shouldn’t automatically assume the worst.
Skin tumors in dogs range from non-cancerous cysts and moles to cancerous growths like mast cell tumors or soft tissue sarcomas. When your veterinarian evaluates the growth, he or she will assess it in several ways. First, whether the lump is on the skin or under it. Next, the size and color of the lump, and how firm or freely moveable it is. Whether your pet has had other growths in the past is also important, as well as whether they were removed and biopsied.
Skin growths are assessed by either a fine needle aspirate: poking the mass with a needle, removing some cells and sending them to the lab to be evaluated, or by a biopsy, where a piece of the growth is removed or the whole growth is removed and sent to the lab for evaluation.
Tumors are assessed for the type of cells and the grade of malignancy, which means how quickly is the tumor growing based on cell activity that is seen on the microscope slide. If the tumor was removed entirely during surgery, the edges or the ‘margins’ of the tumor are also evaluated to make sure that the edges are free of cancerous cells. If there are cancerous cells left behind (not visible to the naked eye), then the tumor will grow back, and the area needs a second surgery to remove all traces of cancer. Depending on the type of tumor, the surgical area may look a lot larger than you expect. Soft tissue sarcomas, for example, extend rafts of cancer cells out from the tumor, attacking healthy tissue with microscopic tentacles of cancer. In order to remove all of the disease, the incision has to be much wider.
Some skin cancers respond well to radiation or chemotherapy, which is as available for pets as it is for people. The good news is that pets don’t suffer the same negative side effects from chemo as people do, such as losing their hair or having gastrointestinal problems.
If the growth is a small cyst, mole, or fat-growth called a lipoma and not causing your pet any pain or irritation, your veterinarian may elect to leave it alone and simply monitor it for changes. The best way to help your pet stay cancer-free is to conduct monthly lump checks when you are petting your cat or dog. Simple run your hands all over your pet feeling for anything out of the ordinary, and if you feel a growth - schedule an appointment to have it evaluated by your veterinarian. In the meantime, don’t panic. Chances are it isn’t a malignancy, but even if it is, there are good veterinary treatments available to help your pet live a long and healthy life.