Elusive abscess

["C Eyler" <eyler@mindspring.com>]

It seems that my gelding may, again, have an abscess that is very high up in
the hoof and which does not respond to hoof testers (farrier felt a slight
pulse).  Last year he finally blew out a 1.5" hole along the coronary band
of the same foot about three months after the first incidence of
intermittent lameness (he'd go from slightly off, to sound, to dead lame, to
sound, to slightly off -- until the final week, when he was consistently
three-legged lame).  Took another six weeks before he was no longer sore
after the slightest work.

This time it's not a complete surprise because late last fall the vet saw a
"shadow" on the x-rays that he thought might be another abscess.

Can't dig it out -- where is it?  Can't soak him daily for three months --
two weeks is about as long as his patience will last.  He's sound for the
moment (trotted him on a short lunge line yesterday afternoon).

What do I do now?

Cindy