I would say that ulcers are very common or toothaches. ~> http://dentistry.about.com/od/toothmouthconditions/Dental_Problems_Conditions_and_Diseases.htm
Dogs now have the same gum and teeth problems humans do. They will get cavities, gingivitis, etc. Many eat "human" food/treats and most eat commercial dog food which have fillers, dyes, chemicals,...
Big teeth.A hamsters teeth never stop growing so they have to bite some thing all the time and don't give them LOT'S of treats they will get fat and lazy they will get SO lazy they will not run in...