Yes, you should have him neutered. This will usually help. To help get rid of the urine smell, you can go to your local pet store and buy something there. I briefly had a cat that sprayed and I bought some of this I think it was called "Nature's Miracle" and this took the odor out of whatever was peed on. You should also have the vet check him out to be sure it isn't a physical problem. Good luck. Please keep us posted.