He has been going down hill but in the last week he has stopped eating & stopped drinking water altogether and so we gave him boiled chicken and white rice which he ate immediately. Then he threw it all up and the next day we gave him a little more, but he threw it all up. Now he throws up bile and is very weak and can't seem to get comfortable. He sniffs the water dish but won't drink.

What does your Vet say? At that age it could be anything but it sounds like the dog is uncomfortable, perhaps in pain, perhaps suffering.

If you stopped eating and threw up for over a week and were uncomfortable, would you go to the Doctor?

Maybe your dog is shutting down. You should take him into the vet for a check up.. Sounds to me like he is dying :(