((SunAngel)) I'm sorry that you had to part from him so soon. It's cliche and it's already been said, but he's in a better place now. You did the best thing for him.
My mom is a vet, and in one of her exam rooms she has a framed poem called "A Dog's Prayer", the last few stanzas of which I have included here:
"And, my friend, when I am very old, and
I no longer enjoy good health, hearing
and good sight, do not make heroic
efforts to keep me going.
I am not having fun. Please see that my
trusting life is taken gently. I shall
leave this earth knowing with the last
breath I drew, that my fate was always
safest in your hand."
While searching for the exact wording of this poem, I found another that I think might be comforting to you:
THE BEST PLACE TO BURY A DOG
"There is one best place to bury a dog.
"If you bury him in this spot, he will
come to you when you call - come to you
over the grim, dim frontier of death,
and down the well-remembered path,
and to your side again.
"And though you call a dozen living
dogs to heel, they shall not growl at
him, nor resent his coming,
for he belongs there.
"People may scoff at you, who see
no lightest blade of grass bent by his
footfall, who hear no whimper, people
who may never really have had a dog.
Smile at them, for you shall know
something that is hidden from them,
and which is well worth the knowing.
"The one best place to bury a good
dog is in the heart of his master."
- Ben Hur Lampman
Your dear dog still lives on in your heart, healthy and pain-free.