I think the teaching him to get along with the cat issue might be easier to solve, so that he can then just follow you around as he wants to. We have 5 dogs, one a cocker and the others various breeds/mongrels. The cocker is the one that has to be by my or OH's side day and night. We can leave her if we go out but if we are at home, there she is - sitting on a chair next to me while I work at the computer, on the bed at night, in one of our laps each evening and, like you say, she never misses a trip be it to make a coffee, fetch something from upstairs or switch on the light. As soon as we move, she moves. I wouldn't have it any other way. Our other dogs have increased levels of independence. Three are currently asleep on our bed and one is downstairs on the sofa. That's the difference with cockers.