[nneessaa]

Male and female dogs can both be called neutered but spayed is the more common term for females. Yes, get him neutered ASAP. Scruffs used to mark over the house and stopped after he was neutered. It took a month.

Have you tried crate training? Keep him in the crate if you can't watch him. Otherwise, attach him to you (leash or on your lap). How often does he have accidents? Is he pee-pad or outside trained? All of what you listed that you tried are pretty negative techniques. Give him praise and a high reward treat (like boiled chicken, or his favorite treat ever) any time he pees or poos outside. Scruffs has accidents once in a while, but we just started clicker training and he hasn't gone for almost a month now. I don't know if I am doing it right but I click and treat when he goes outside each time. I think it is right. I think positive reinforcement and controlling where he is allowed is what most people will advise you to do, but I've been working for a year with Scruffs and he is still not 100% trained. Stubborn dog he is...

Edit: by stopping I meant he stopped marking. If you mean your dog is just marking constantly over the house I think you have a good chance of it stopping at one year old, but if you mean peeing neutering may help but you will have to go back to square one for training.