About six months ago or so I noticed a small pea size growth on the outside of my dogs paw. we took him to the vet and they didn't seem concerned about it but it has grown a little bit bigger (im not sure if due to it being irritated) to the size of a pistachio. he doesn't seem bothered by it but occasionally bumps or scratches it by accident causing to to bleed. were taking him to the vet today to possibly get it removed, but what could it be? he is a 10 year old bulldog mix in great health aside from having allergies and being prone to skin issues.