Dormosedan in the correct dosage works wonders, and will wear off reasonably quickly. Ace will also work, but not quite so well. Rompun -no way- they can still snap awake and kick.
Sure, let the farrier evaluate, but this horse is sedated for the farrier
https://www.youtube.com/watch?v=ic3AkkXUdZE
If they need it, and farrier agrees, absolutely get it done.