madmentalbint - better a week too early, than a day to late. Absolutely can't echo that enough.
ggirl - you are going to have to be very brave. When i lost my beloved Tiny (9stone rotweiller!) I felt much the same as you do now. He had kidney failure and we had tried a 24 hour drip to which he responded to really well - had gone from a state of collapse to a bouncy happy boy. Within twelve hours he was back to square one and i knew the time had come. I was a vet nurse and have seen this time and time again and knew that OK, i could buy him a week or two but having him on a drip (i could even have him at home to do it) but i knew i would be doing it for me. It was awful - I absolutely had to go to work that morning so i got my parents to dog sit and when i got home he was at the door to greet me. So, i thought ok, i'll take him over and see what the vet said. He said the same as me, you can buy him a week, maybe two - So there we were, stood there in the surgery - I was in tears, DH in tears, the nurse in tears, the VET in tears (I worked there remember so he loved tiny - everyone did). I looked down at my dog and he just looked at me as if to say "Let me go, I've had enough" and i chose to let my boy go. It was the worse decision i have ever had to make and i woke up that night screaming that i had done the wrong thing, I wanted that two weeks with him - BUT, i did totally the RIGHT thing for him. There was no way i could let him suffer anymore - poor dog, he just knew he felt terribly sick, was in pain and he just wanted to go to sleep. The end was peaceful, i cuddled him while he went to sleep and was able to stay on my own with him for a while afterwards - DP couldn't stay but came in afterwards to say goodbye.
Ggirl - letting our animals die with dignity is the best thing we can ever do for them and we owe it to them not to allow suffering. I know it sounds harsh but i know just where you are at right now - the best advice i can give you is listen to that feeling in the pit of your stomach, dont listen to your heart - it wont ever want to let go and don't listen to your head, it will try and rationalise, oh, but he had a good day today, maybe tomorrow will be good. I think its time to let go - your dog has had a lovely life with you and you clearly love him very much and he will know that and take that with him.
Wishing you strength xxx