Ashes can be tested for DNA - I believe in this case it was found to be cow.
Whether you could identify a specific animal, I doubt it - you would of course need a hair (follicle) or tissue sample from the dead animal for comparison
OMG, David Nutt came to take away my pony when she died. Have to say, i didn't think much of his people skills.
He asked my if i wanted one of her shoes which he said he would take off and polish up for me and deliver back to the yard. I never did get it.