I have two cats and one of them is whizzing in the basement. He started by whizzing on my personal belongings during a winter cold snap when I wouldn't let him outside. He even left a man-sized turd in my bathtub and sat and watched my wife and I discover it, which was fairly disturbing (I had been home all night and couldn't figure out how somebody could have broken into the house). I chased him around the house and yelled at him and he stopped for awhile.
Then he did it again when we came home from a long vacation. Whizzed all over the house and basement. I didn't yell at him that time, just gave him affection, and he stopped.
We had a baby last winter and he seemed fine, then we went on vacation for a week in the summer and he whizzed all over the basement. I took him to the vet, they gave me antibiotics and said his bladder was infected but didn't have crystals. I gave him antibiotics for awhile, he stopped, and now he started doing it again. I am putting him back on antibiotics again but I feel like he is doing it for attention or to get back at me.
He already goes outside a lot and is very affectionate. He is also neutered.
Any ideas for how I can get him to stop?