I have a 5 year old dog. He is a collie. He "was" potty trained and he started peeing on the corner of furniture and right by my cats litter box. Its not a bladder infection, and he is not neutered. Me and my dad always argue about this and he thinks that hes just not potty trained and stuff. But he is still potty trained. I keep telling him that hes doing it to mark his territory and if we get him neutered he will stop. When i clean up the pee i use cleaning products. Ive seen him do it and he doesnt even smell the spot. I put him in time out even. WHAT DO I DO? WHOS RIGHT?