Hello all, my one year old male cat Gabriel occasionally does something very odd when playing and it's something I've never come across before with a cat. When he has the crazies, pupils dilated, full blown sprinting around, etc. occasionally he'll hiss then do something like panting but it's louder for 3 or 4 seconds then his breathing is completely normal. I don't think it's actual panting because of the short duration and the fact that he doesn't bother to rest during or after it. I'm a bit concerned about it even though it's only an occasional behavior and doesn't appear to be causing any distress or anything simply because I've never encountered another cat that does this nor have heard of it.