My husband and I adopted a little orange cat we named Peaches last September. He had been wandering up to a friend’s house for about a year, and they couldn’t take him. His microchip told us that he was at least 5, but his original owners never claimed him. Things were going really well: he was getting along so well with our other two cats and seemed really happy. But a couple months ago, he started spraying in our back hallway. At first we thought it was anxiety, so we tried the pheromone plug ins, gabapentin, tons of enrichment and attention, and nothing worked. Our vet (who is also a behavior specialist) has come to the conclusion that he is wanting to go back outside now that the weather is nicer. He keeps spraying on upright surfaces and tends to spray our door in the back hallway, so she thinks it’s territorial. We’ve tried taking him out on a harness every day. Our other two are already harness trained so it was an easy transition. But the harness only seemed to help for a couple days. He began peeing again, and now he wanders around crying and just seems miserable. We’ve decided transitioning Peaches to indoor/outdoor is the only solution that might make him happy. I am VERY anxious about this transition, and I was wondering if anyone has some experience/advice to do it as smoothly and safely for him as possible. His original location was in town. We also live in town in an area that feels pretty similar to his original location. We do have woods not far away and occasionally hear coyotes run though though. Any advice would be appreciated.

Need advice transitioning Peaches to indoor/outdoor