I need a bit more info so I can help answer your question
How big is the lump and how long has it been there?
Has your dog ever had a dental and if so, when?
which tooth is the lump by?
is it bleeding or affecting his eating at all?
THe lump is about one centimeter. Pretty large although just discovered it today. The dog is 10 and has had about 2 dentals. The lump is by the front left tooth. No it is not bleeding or affecting his eating.