For older horses that have difficulty with the farrier, I use a combination of things. First of all, I give an appropriate dose of Bute the night before/morning before the farrier comes. These horses hurt, and making them comfortable really helps. Then, I use a small amount of IV dormosedan as a sedative. These horses know it is going to hurt, and they tense up in anticipation of pain or in reaction to pain and make the situation worse. Dormosedan (as prescribed by a veterinarian) provides some relaxation which often seems to help greatly.
A horse that nearly falls down when you pick up a foot probably deserves a vet visit to quickly rule out a neurologic problem. It’s possible that your vet would have some other ideas as well. IME, blind horses have zero issues standing for the farrier, I doubt that’s the issue.
You may see a dramatic improvement in the ability to pick the horse’s feet up after a dose or two of bute. If you don’t, I’m going to be very honest here, I think that it is unrealistic /unkind to keep a horse that is too uncomfortable to tolerate basic farrier care in a safe manner. Not being able to hold up one leg for a couple minutes can be an indicator that a horse is significantly physically unwell or in pain. It was an incredibly kind deed to rescue this horse, even if it ends up that you did it only to give him a few good weeks and a painless end.
I would urge you also to consider the point that your farrier is likely not going to be excited about this project. Farriers do not in general like to work on draft horses, let alone a draft horse that can hardly stand on three legs. Would you want to? I don’t know how good your relationship with your farrier is, but this is not going to endear you to him or her. Be prepared to pay extra/give a tip.
