Bless you for taking in this sweet boy. I understand your dilemma.Once a cat gets a taste of the outdoors he wants to get out there. He does not understand about fights, predators, cars or diseases.
However, you should not have to pt up with spraying, crying and psychological trauma.
I suggest you train him to walk with a leash and harness. Then you can take him out twice a day, let him spray the bushes, climb a little and get some exercise.
In addition, catify your home and the outside catio by placing shelves in various places to allow for vertical climbing.
I would also put him on amitriptyline to stop the spraying.
Please let me know how this works out for you.
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