I had Kirin going last night with the feather-on-the-end-of-the-rope toy and after we were done, he was walking around the house with his mouth open and tongue out, and it sounded like he was panting or wheezing or something. It stopped and I haven't seen him do it since, but I had never heard of a cat panting before. He's not overweight, he gets plenty of exercise (what with 3 other kitties plus a dog), so I don't know what it could've been.