I am sorry to hear about your toad... sometimes we do all we can and still not get the result that we wish for. I think most people can not understand just how attached one can get to a cold blooded, non-furry creature.

I beleive the last act of kindness we can show, once all hope is gone, is to let them go. Another painless way to put them dowm is to put them in the freezer. Being old blooded, the drop in temp slows their systems down, until their systems stops.