I posted about this before but my cat twinkie (DMH) is 5.5 months old and has been panting recently. He did it before when I brought him home and has done it off and on since then and lately it has gotten worse. He will play for a bit and then sit there and pant and then resume play. I took him to the vet and she listened to his lungs and heart. She said they were both "great" and he has no temperature and appears to be in good health. Is eating, drinking, running aroudn and doing normal cat-like things. The vet said she didn't think it was FIV, leukemia, etc. but dind't know what it was and told me to monitor it for now and call her if it gets worse. I'm very worried about him! any suggestions on what it could be??