What a dreadful thing to happen.
We were very lucky Jonty didn't end up being pts too, the haematoma on her belly was enormous, I think sometimes people have no idea just how vicious other horses can be to each other.
Were anyof them newly shod? we learned a hard lesson never to put a new one that had been newly shod out with others even after a few days of no trouble..
I hope there is somewhere else for Dolly to go, whatever attacked her will do so again I'm afraid.
She was obviously the most lovely mare from her picture, I am so very sorry for your loss.