Q. I have a five-year-old Boxer. Today I noticed a mass around one of her upper teeth. It does not seem to hurt her when I touch it. Her appetite is very good and I would not have noticed it except when she yawned I saw that her gums looked red. What could this be?
A. I would be concerned. Any kind of mass in the oral cavity of a dog is potentially life-threatening due to the possibility of a malignant tumor. In addition, Boxers are on the top of the list of dog breeds most susceptible to cancer.
The most common tumor in the mouth of dogs is a melanoma, a dark-colored mass that can spread to the surrounding lymph nodes and lungs. The tumors can be invasive to surrounding bone, requiring a radical surgery to remove part of the jaw for treatment. The second most common tumor in the mouth of a dog—squamous cell carcinoma—is also highly invasive into nearby bone, but does not spread to other parts of the body. Surgery is also required to remove these, followed by radiation therapy.
With both types of cancer, survival averages one to two years and the length of survival partly depends on how large the mass is. This is why it is important to get any mass in your dog's mouth checked out by a veterinarian as soon as possible.
However, there is still a stronger possibility that the mass you are seeing is not a tumor, but simply excessive gum tissue or a benign mass. Since your dog has red gums, she may have advanced periodontitis (gum inflammation), which can lead to the growth of benign masses in the mouth.
Your veterinarian should do a biospy, which will require sedation. A small piece of the mass will be removed and sent to a veterinary pathologist for diagnosis. In some cases, removing the entire mass for biopsy makes sense, but with a mass in the mouth it is better to get a small biopsy first, so any surgical removal will be extensive enough to get all or most of the tumor.