[troubletb]

This is a very hard decision and I don't envy you. I had to make this decision a few years ago with my Westie and it was one of the hardest in my life. Usually with an enlarged heart they don't last long. My brother's dog had that and he came home one day to find his beloved dog gone. (He was a dalmatian) and he had to remove him by himself. That is one of the few times I saw my brother cry.
So I think it is better to put him down, then to have to come home one day and find him gone. What ever your decision is I'm sure it will be a good one. God Bless.