I have a 20 week old Boston Terrier named Pudge he is so sweet and loving! My question is that i know that they are supposed to have their adult teeth by 6 months and Pudge hasn't even got any of his back teeth but he's got his other puppy teeth but none of the other s has started coming in yet? What should i do? He has teething toy's and biscuits. Should i be worried and take him to the vet? Any advice please help!?