My beautiful, tiny "Kitty" (long hair calico) never grew bigger than a 6 month old kitty. Very prim and proper. Let her out when she wanted to go out and one day she brought home a boyfriend "Bum". He was a huge (muscular about 20 lbs, no fat) yellow tom with one eye, broken tail, one ear bitten in half and never knew how to clean himself. He stayed outside,since we didnt know anything about him. The vet said he was about 6 years old and probably never lived with humans, even though he was loving and healthy. After three failed litters, we had Bum fixed (HE DIDN'T EVEN KNOW HE WAS BROKEN)and he cleaned himself up and became a house cat. Unfortunately, Kitty died from cancer and Bum became the only cat. He began to spray again, even though he was fixed. The vet began giving him hormones. He gave him to much and for a while, poor baby thought he was in heat, but it finally cleared up and he stopped spraying--we were told over and over he was peeing cuz he 'couldn't spray'. It was spray--hormones screwed up after Kitty died--go figure.
Then there was Macaroni, he didn't like the litter box, cuz the dogs went outside. I ordered one of those Train Your Cat To Use The Toilet kits and he did learn to use the toilet, yet he would fall in once in awhile and decided to go back to his litter box.
By the way, you know the gifts cats bring home--HONESTLY--He brought home LIVE BAT carried by the tail. It was hell getting it away from him and he never went outside again--EVER.
Mr. Mischief Whiskers, my loves cat, refuses to use the litter box. Naturally the cat gets better care than me; he installed a cat door. Now, he invites the fox in to share his dinner, but the rest of the critters: rabbits, mink, birds, weasles and small children, he either brings in just the head if they don't fit through his door or the whole thing if it fits. But even in the coldest days of winter, he still goes outside, just does not like the litter box.
Cats are fickle and get quirky just like humans. Ever heard of a shy bladder? Many things can be effecting your baby. He may even have a problem with the chemicals added to the kitty litter, try plain sand and then work up using lesser odor stopping litter. IS IT TO CLEAN. Sounds silly, but if his smell is not there to his liking, he may not feel welcome.
"Kitty Litter" by Golden Cat is manufactured in my hometown. I always wondered who had the job of testing the "smellability"! EEWWWW