Thinking of you at this difficult time, I think its one of the hardest things we have to do for our babies, Like every one says, and from our own experiance. I truly believe that if they have an illness they let you know when its time. Belle sound like she is such a trooper, still full of playfullness and lots love, I think it would be different if she was just laying in her crate with little energy and if she was showing any signs of her being in pain, right now that doesn't seem to be happening. Hope and Faith is all we have when our babies get sick, don't let go of either until you have too.
Keeping Belle and your family in our thoughts and prayers..
Sending lots of vibes & hugs and love your way..~ Vickie