I sure hate to see that Bay is having foot troubles again. If there's any chance that it might be a laminitis flare up, you might want to ice his feet. In that clinic I went to, they said icing was one of the best things to do, and to keep ice in the water at all times, not just cold water. I wouldn't bute him because that'll mess up the evaluation that the farrier or vet might do. I think I'd go ahead and go with the vet.
I'll let you catch up... the update is we ended up ruling out laminitis and the vet is coming this morning. I had already given Bay the big dose of Isoxuprine and the Bute last night when the vet called with the change in plans, but he said OK, just don't give him anything this morning.
Finding and dealing with lameness is this vet's favorite specialty. He really enjoys just watching horses move and finding the problem. He spent hours here watching Bay the first time. He didn't want to come till he had time to do that again. When he leaves, I'm sure I'll feel like we found the problem.