We got Kirby that was only use to a doggie door..not what is really housebroken..and he was 3..he still dont know to tell you he wants out..we have to take him out side on a consistant basis to make sure he goes..he does not go in the house any more..but still dont tell you he has to go..
He never learned as he was always use to the doggie door..but he holds it now till outside time.. We just kept telling him outside and no no if we caught him about to go inside and took him right out, took some time and lots of patiance, and it was frustrating for him to..