Those sound very large feeds! Have you weighed them? It may be that you are giving her too much in one go and as a result she isn't able to feel the benefit of much of the feed.
Heartbreaking as it is for you right now, I think you've had a lucky escape too. I've had a couple of failed vettings when horse hunting, which I was gutted about at the time, but I think I then found better horses (who were sound!). Good luck in your search.
I've always been sceptical about calmers, but on my vet's advice I used Prokalm for when my boy (also known as the duracell bunny!) had to be on boxrest and I am staggered at how effective it is. It is pricey, but I've claimed for it on my insurance.
On the recommendation of my osteo, I have hired an equilaser to use on our horse who has recently suffered a trauma injury to the medial branch of her suspensory.
Has anyone any experience of using laser treatment on an injury like this? Would I best to use it before or after her ten minutes...
Have you tried Prokalm?
I used it when I first started ridden work with a horse who had been on boxrest for months and months, and it certainly helped take the edge off her (she's a sharp horse anyway!)
He passed me between huntsman's close and the quarry and smacked the horse who looked completely exhausted - I've never seen Armada look like that before. I was very uncomfortable seeing him pushing the horse on and I'm not surprised he was disciplined for it. I would have welcomed the officials...