Just a thought jan (you didn't tell me about his "hitch".) That's what the Caldor kittens sounded like and turned out to be lung worm. It wasn't the usual strongid that the swedish vet prescribed at North Shore- it was something else. and I remember she said it is a mystery on where cats get it from exactly but believed to be from eating raw birds and/or mice- they were not sure. The lung worm was, at that time, an unknown, and so they were treated with a medicine, hitch cough stopped, and now live with me (as you know!). Again, just a thought...
Of course I will donate too!