Not Sure What To Do

My oldest cat who is about 12 has been pooping outside of the little boxes from time to time. At first I thought it was because he might be having trouble with his back legs. I could understand if he couldn't climb in and out of the boxes. However that is not the case. He is able to climb and jump just fine. He hops up to the top of the couch and tries to take my food when I'm eating. If he can do those things, he can do his duty in the boxes.

It has gotten to the point I am very frustrated and get angry when I come home to a steaming pile or two on my rug. Thankfully the other cats aren't doing it. Also the cat doing this behavior at times goes in the boxes. I try cleaning them out every day, but at times it does not help.

The last three times I really lost my cool with him. I came home the other night to two piles of poop on the floor. I grabbed him by the scruff, put his face near it, yelled and smacked him. Tonight I have gone off twice. I came home and found a pile near my bed. He was on the bed so I did the same thing. The crazy thing is he doesn't stay scared long. He comes right into the kitchen a few minutes later. Maybe it's because I was in the process of feeding the cats or he was curious and forgot about the ass whipping. The second time I have gone off tonight was when I heard him taking a dump. I walked out into the living room and sure enough he had gone on the floor. I chased him and he made it to under the bed. I flailed my arms trying to reach him but gave up. As I write this, he is out from under the bed and eating. I have calmed down enough to know I will not go after him again.

The thing is I am not normally tempermental with my cats. Sure I may yell if there is a fight and/or toss something into the mix to break it up. However I am really losing patience with this cat and getting to the point of not loving him anymore. I don't wish to smack him so hard that I hurt him or toss him out the door. On the other hand I am tired of him doing his thing on the floor. I am going to have to tear up the carpet because of it. I'm also in the process of getting back into the dating game and don't need to be embarassed and make a bad impression if I bring someone home and there are piles on the floor. I would never want to get rid of a cat if someone I dated didn't like cats. However I don't want my happiness to be impacted by this.

If all else fails, I have thought about putting him down. The thing is I don't think he deserves to die for going on the floor. Then again I don't want to live like this and become and full blown animal abuser for losing my cool.

Any advice will be appreciated.