I'm sorry you are going through this again and empathize with you. I let Taranis out of isolation yesterday to see if her new "mood altering" and very expensive medication has worked yet. She peed all over a love seat. Like you, I keep having to take her back for more expensive tests to make sure she doesn't have an infection or crystals, and it feels as though you are pouring money into a bottomless pit of no sure fix.

It may well be that the adventure Pouncer went on has affected his behavior, especially since he's now afraid of being outside instead of curious. Many years ago, my landlord let out my very nervous male cat while I was at work and I didn't get him back inside until that night. He sprayed up a storm after that and he'd never done it before.

I can't remember, do you have Pouncer on any kind of sedative?