Have you told Baron's breeder about this???
This could be a congenital problem and they need to be aware of this.
There should also be something in your contract that states they need to be notified of any health problems.
They will most likely take Baron back and give you a healthy puppy or least help with the surgery bill.
If it truly is a liver shunt (and it does sound that way) surgery is your only option or he will not live a very long or happy life at all.
At the very least, get a second veterinary opinion and get in touch with your breeder right away.
Jeannie Thomason, V.N.D.
The Whole Dog
http://www.thewholedog.org