Very tough to take.
I lost my old Labrador to his back going out suddenly. It seems he had an undetected weakness in his back that had been there some time, so long that a 'bone bridge' had formed to try to compensate. It worked, until his foot had an issue and was wrapped, and he was having to hop in the back. It was a surprise when he just couldn't get up off the floor the next day, not in any pain, but completely paralyzed. Xrays showed his back was broken and he'd not walk again. He had a ticking time bomb there.. a little weakness we'd never have known about before it went off. Perhaps this incident with Barbaro, and your horse were similar. A leg is only as strong as it's weakest link. :~\
I'm sorry. *sniff* S'pose horsies go to the Rainbow Bridge like other animals, or do they have their own bridle path to the Great Beyond, where they await us?
Wherever it is, I hope you will be reunited with your steed when the time comes.
~~~~~
I'm trying to picture what that pool raft looks like for post-op recovery. First I'm thinking of the inflatables we all have - seeing a humongous horse lying with its head on the little pillow.
Then I'm thinking more along the lines of Cleopatra's barge on the Nile. But Barbaro is a boy! So, I guess it's made out of lumber or old boards and is a Tom Sawyer/Huckleberry Finn kind of raft with a little piece of cloth for a flag, lol!