Difficulty Breathing while Lying on Back

I originally posted a question here in July; here is the link...
http://www.medhelp.org/posts/Animal-Health--General/Kitten-Swallows-a-lot-when-Purring/show/1002168?camp=26

In addition to the what is mentioned in the above link, we have noticed he begins to have a problem breathing more when he is on his back. We initially thought the problem was with him purring. This is what we know now...

When we hold him, cradling him like a baby, in our arms, he begins to struggle to right himself up off his back. He begins to lick at the air. He also begins thrusting his head from side to side. If it goes far enough, he will begin to make a slight noise kind of similar to a faint cry or wheeze. Also if gone this far, he will breathe with his mouth open slightly. He does not go as far as panting.

He has a great appetite, eating about 1/4 - 1/2 of a 5.5 oz can of cat food per meal. He drinks regularly and uses the litter box regularly. He plays with cat toys and the other cats just fine.

When we mentioned the difficulty breathing at his last vet visit, Aug 10th; however, we only told her he seems to have a problem when he is purring. She listened to his heart and lungs. She could not determine anything out of the ordinary. Now I think we have figured out he has these problems when he is lying on his back. I wonder if she could not determine what was going on because he was standing on the little exam table. I wonder if she could have heard anything if he were on his back. I told her at his visit I was hoping to find out what might be the problem before he under goes anesthesia for neutering.

Do you have any ideas what would cause a kitten to have appear to have breathing issues while lying on his back?

Thanks in advance. I will be calling them on Monday.

[Dean Vicksman, D.V.M.]

Thanks for coming back with more information.  As veterinarians the more information we have the better we can diagnose potential problems. Unfortunately the clinical signs that you describe are still to nonspecific to diagnose the problem. I would recommend 2 things at this point. First, during you next exam demonstrate the problem for your veterinarian.  Actually seeing the problem for ourselves can be very helpful.  Second I would recommend a chest xray.  If the xray is normal I would not be as concerned about the behavior.
Keep me posted.
Thanks,
Dr Vicksman