i just got a new dog, he is about a year old. the people i bought him from said he was housebroken, but i've had him for a few weeks now and he really isn't listening. he will go outside and pee just fine, but he refuses to poop in our yard. he will either do so in the house or when we go on walks. obviously i don't want him going in the house, but i don't want to be cleaning up my neighbors' yards, either. i don't know how to get him to go in our yard and not out on walks. i don't know how his previous owners trained him and if that's just what he's used to, but i need some advice on how to re-train this.