4-17-13
With no success in our attempts to feed him, we decided it was time for a vet visit.  He was taken in this evening, and they performed a Barium Swallow Xray on him, and discovered that he had a "persistent right aortic arch".  In layman's terms, he was born with his aorta wrapped around his esophogus and pinching it off.  It is open just large enough for a liquid diet, and therefore had no trouble growing older on mother's milk. 
Unfortunately, the only fix is surgery.  It is a very risky surgery, but if successful should give him a full, healthy life.  Without the surgery, he would have to be on puppy formula possibly his entire life.  In addition to that, it has the chance od completely closing and killing him. 
Our vet will be performing the surgery in the near future.  We have to give him his shots first. 
We decided it was well worth the cost to have the surgery done.  As mentioned, there is risk involved, He may not make it through.  But this is the only way to him the life he deserves.
We will cerrtainly keep everyone informed.