I second the muzzle/poop guard to keep him from the splint.
For what it is worth, I once had my "sister's" iggy with me at her house for a weekend, and she broke every bone in her foot by putting her foot down a hole while running. She had the surgery that put pins in her bones and while recuperation took a couple of months, she was absolutely fine afterward. The vet had another dog come in the same day with the same problem. That family couldn't afford the micro-surgery to put in the pins. The vet monitored both dogs to see how they healed. Both dogs regained full use of the foot/leg. A long way of saying, there is a fix out there if Augie's bones will take the pins, and even if they can't, there is still a really great chance that rested and not run, he will have the full use of his leg.
Lots of continued prayers for Augie and for you.