I would make an appointment right away with someone who has experience with small dogs. He is big enough. It takes a few months after the neuter for the male hormone thing to subside and hopefully he will stop marking.
Others with more experience with marking may have some more ideas. Some people use belly bands but I would think it is a behavior that you have to deal with as well.
I had a yellow lab years ago and he would lift his leg on every tree and telephone pole he met but he never marked inside. He was neutered when he was a year old. |