>Well the only thing wrong with him that I can see is that he toes
>out just a little bit up front.  That's it!  I think this is because his
>cannon bones are slightly off-set to the outside.  He is sound, clean 
legged
>and 9 years old.  Can you all tell me how this toeing out could effect his
>gate, or soundness doing long distance riding?  I can't figure how his 
would
>make him interfere.
A horse should track straight ahead.  However, when they toe-out, they tend 
to swing their feet inward from the track.  Thus, more apt the hit the 
inside of the opposite leg.  That may happen occasionally or frequently 
depending on the severity of the problem.  Plus the heavier the shoes the 
horse wears, the more emphasis to the deviation of the tracking.
The tracking and occasional hitting the inside may pop an occasional 
splint.  This can be avoided with boots.  However, this problem is not the 
main problem you will have with this horse if you plan to do endurance.  If 
he toes-out at all this means the bones somewhere in the legs or feet are 
not straight.  So, the horse will not bear weight efficiently and will 
eventually break down, or be chronically lame, under the footfall 
repetition required in endurance.  
I've seen horses win at the race track with horrible toe-outs, toe-ins, 
club feet you name it.  However, they only work and perform a short amount 
of time.  Plus, career time on the race horse is relatively short.  
(Probably very short for one with limb deviations).
In my experience, it is a waste of time an $ to train a horse for endurance 
with anything less than near perfect legs and feet.  If you wind up with a 
horse that is not near perfect, I'd pick a different career for them than 
endurance.
I've been there. My hindsight is 20/20.  Since then, I've also observed 
this happening over and over to fellow endurance competitors.  Can't fight 
physics. 
Linda Van Ceylon