A range of vet investigations had been done, but had stopped short of MRI, so it still wasn't clear whether the problem was DDFT or not - the X-rays weren't bad, but the horse had nerve-blocked sound to the back of the foot, hence the diagnosis.
I hadn't seen it before, but had had its lameness described in detail, so both the owner and I were in for a surprise when it appeared significantly sounder on the lunge yesterday.
What had changed? It had been shod the day before with heartbars :-)
Now, neither the farrier, the owner nor I expect heartbars to be the end of the story, but they have certainly provided an improvement in soundness for this particular horse at the moment.
Some horses actually go immediately worse in heartbars; some are sounder - although in my experience the soundness does not last longer term, and most horses become lame again over time.
For this horse, though, they had made the difference between a lame horse unwilling to go forward and a horse which was to all intents and purposes sound in trot and very willing to go forward. It may be that the improvement doesn't last, in which case there are other options, but for now, if it ain't broke...
* For guidance on the use of this term in this blog, see this post: rockleyfarm.blogspot.com/2009/10/navicular-horses.html