heat in hoof

[GoferI@aol.com]

My horse has been giving me and my farrier a perplexing time for a couple of
days, and I was wondering if anyone else has ever had this problem. 

My farrier pulled my horse's shoes about three weeks ago since I'm not
competing for awhile, and he was initially a little footsore when turned out.
After three days I resumed riding him in the indoor arena only (five or six
days per week) and he was fine. Then yesterday I noticed a little heat in the
left front foot. I rode him and I felt him take a few funny steps but he
wasn't three-legged lame. So I soaked and poulticed it until the farrier came
out today. He found nothing in his search for a bruise or puncture, but the
hoof is still a little warm. There is no swelling anywhere else on his leg or
on any other legs. There was some tenderness in both front hooves in the front
area of the sole with the hoof testers (not in the middle, near the frog or in
the heels). 
	
My farrier suggested continuing the soaking in case it's an abcess, but he
wasn't at all certain of that diagnosis. He said it wasn't hot enough to
indicate a true abcess. He suggested putting the shoes back on in a day or so
if he remained the same. After he left, I took my horse down to the indoor
arena to see how lame he was on the longe line, and he was perfectly sound
both directions at all gaits. 

I know heat is indicative of an infection or inflammation, so is an abcess a
likely cause?
Is this heat perhaps a remnant of some bruising from initially pulling his
shoes? Could a horse be sound and have more heat in one hoof than others for
another reason?

Thanks for pondering this,
Tricia
(you can e-mail me personally (Goferi@aol.com) so as not to clutter the list)