My boxer is 10 years old. He initially appeared to have a "double chin" which has continued to get bigger. Some days it feels very fluid, other days the skin is taught and seems full of fluid. I've taken him to to vet and was told that he may have a cyst or blockage in his saliva gland or a tumor on his thyroid. He has been on Rimadyl for arthritis and the vet said that should help with the inflammation. She said that surgery would be the best option to determine for sure what is wrong, but I'm hesitant, due to his age. However, the last couple of days, the swelling in his neck has increased, his bottom lips are larger, and feel hardened, and this morning the right side of his face is swollen - up to his eye. Any thoughts or suggestions?