My 8 month old doberman goes threw a bone a day like its nothing and i dont know what to do?

i have an 8 motnh old doberman, ibaught him raw hide but he goes threw it like its nothing, i baught him bones he can eat a 12 inch bone in a day, i baught him some other type of raw hide its really reall hard harder then a bone and he goes threw it in a day, what can i buy him that will take him a while to go threw because nothing seems tobe working