Servinator, I once had a horse come up extremely lame very quickly. So quickly he went into a full blown colic. Vet was busy with the colic and with the banamine in him he didn't show lameness. She looked later and did not see any sign of a "hole" so did not think it was a thorn etc that could have caused foot pain. She came back a few days later and still did not diagnose an abscess. It took that gelding a month to blow that abscess. And it was a heel abscess. They seem to be vicious things.
I said all that to say, vets can't always diagnose abscesses. Without xrays they really can't be sure of what is going on sometimes..
And shoes suck for navicular anyway..
That's my story and I'm sticking to it.