Yes, he has been neutered. This has not gotten rid of his marking though. He marks everything outside. He will even try to mark when he doesn't have to pee. He will easily been done peeing 5 minutes into a walk, but will continue to lift his leg, even with no pee left, for the rest of the walk. I guess he is just very territorial. My mother cannot get over how much he marks. It really is kind of funny.