Sounds like a pain issue to me.  are his legs all the same temp, even inside the soles of his feet?  I'd have the vet check him for soundness.  Cheryl of WindWood
--- In training-horses@yahoogroups.com, "equestrianme" <equestrianme@...> wrote:
>
> Hi Ihave a young stallion draft cross,hes 5 and been under saddle for
> 6 weeks perfectly,he lives outside most of the time,with a herd of
> geldings and colts.
> Saturday he pulled left when i wanted him to canter right,but then
> he softened and did it fine.
> On Sunday,he cantered left fine but when i turned right he pulled
> violently and reared,after that he just refused to go anywhere. I
> worked him on the lunge,where he was fine at trot,but reared when
> asked to canter.
> Today on the lunger,left was fine but the minute we turned right he
> started it again,rearing,even in trot,it took 15 mins but he gave up
> and then worked fine in both directions.
> He wears a rubber snaffle and no we cheched his teeth and nothing.
> Any ideas.
>