Awww, I am so sorry for your loss. I hope that you and your daughter will find a horse just as wonderful, I understand no horse will ever be the same and can never replace your wonderful horse but you will find a horse that will fill that place in your heart and will be as loved by you as he was.
I guess this is a bit like what roro said in a way, think of the good times you had with him and the funny and just plain stupid but worth it times.
But my daughter is heartbroken and wracked with guilt, for not vac. Him in the spring.
Tell your daughter that it wasn't her fault, these things happen. No one is to blame.
I hope you, your family and your daughter will be smiling again soon. You are all in my heart.