One of the most common reason pets are brought in to see their veterinarian is for skin issues. One of the more frightening symptoms is unexplained lumps and bumps on the skin, under the skin, or sometimes in the mouth. Most of the time, the cause of the swellings is something benign: fluid-filled cysts, fatty tumors, warts, skin tags, and histiocytomas are all lumps that are benign and usually ok to monitor at home. They can still grow, get infected or make the pet uncomfortable, but they aren't cancer or require emergency treatment.
Other times a lump can signal a more serious condition that requires treatment. Bumps that are painful and appear suddenly can be due to an abscess, which is an infection usually caused by a bite wound. Pets can also get skin cancer, just like people. The worst cause of a lump is a malignant tumor because these lumps can spread to other areas of the body.
If you notice a lump on your pet, monitor him or her at home. If your pet seems to be acting normally and the lump isn’t painful, red, or giving off a bad odor, then it is mostly likely not an emergency situation. Call your veterinarian and make an appointment to have it checked. If you mark the mass with a sharpie pen, that will help your veterinarian locate the swelling. On the other hand, if your pet isn’t acting normal, is tired, doesn’t want to eat, or is limping, etc., then you might be dealing with a more urgent situation.
Your veterinarian is in charge of figuring out what the lump is, and what to do with it. Your veterinarian will most likely ask you questions about when you first noticed the swelling, if it has changed at all, and how your pet has been feeling otherwise. These questions are the history that will help your vet determine the scope of the problem.
Your vet will then examine your pet. The look and feel of a lump can tell a veterinarian a lot about what your pet is dealing with, but don’t be surprised if your vet also examines your pet from head to tail. A thorough physical exam is critical to assess your pet’s overall health and determine if there are any lumps anywhere else.
Once your vet has examined the lump, he or she will most likely offer several options to diagnose or treat the swelling. The vet might recommend cytology of the lump, which is a simple test where a needle is inserted into the swelling. The goal is to extract a few cells that can be viewed under the microscope; often a veterinarian will send the sample out the lab for analysis. The drawback of cytology is that it only can give limited information, which is why your veterinarian may also recommend a biopsy.
There are two types of biopsies: incision and excisional. With incisional biopsy, a small bit of the mass is sampled and sent to a laboratory for analysis. Excisional biopsy involves removing the entire swelling and sending the whole mass in for analysis. Depending on the mass size, location and the temperament of your pet, your veterinarian will recommend local anesthesia (numbing the area) or general sedation.
Treatment depends on the underlying cause of the lump, and can range from lancing and draining (for abscesses), to minor surgery, to something more invasive if the swellings are due to a serious underlying medical problem, like cancer. It is also entirely possible that your veterinarian may determine through physical exam alone that the swelling is no danger to your pet and purely cosmetic, and give you the option to monitor it at home. Again - your veterinarian will be your greatest resource, so if your precious pet has an unidentified swelling, schedule an appointment ASAP.