REscue remedy is Bachs Resacue remedy and bought from a chemist.....no other make cos they are not safe but its really the two cats that fight huim that need to be calmed down and zykline is a capsule I think and can be split open and put on food, but their food not his cos the first thing is to stop him being attacked,
If you can do that then next it would be his turn to try and keeep him calm so he will stay in but he maynot need it if he has a bed and isnt attacked, the key is really with him is for him to feel safe when he is in the house and also be able to get out again when ever he wants