For those of you with bleeders, what made you suspect they had an issue and proceed with vet care? 

I have a colt that I have started letting run and each run he gets progressively more out of control in his turns.  I am trying to discern if he is just overexcited to run or if it is pain/EIPH/other related.  I understand I am going to need to consult with my vet.  I can sprint him on a rail and ask him to break to a lope and he will come down.  Put him on a pattern (barrels or poles) and he fights and blows through the turns.  He will slow work the pattern pretty well up to a slow run.  Then he fights.  Not looking for training advice at this time on here, just info on your bleeders or if you have had something like this medically related.  Thanks!

When I ran my mare I would describe to people she was like running a freight train, or that she was running scared. It was more than just running a free runner. Finally she just suddenly gave me issues not wanting to go to the barrel (not ally issues, but fwd to a barrel issue) and I instantly took her to the vet and had her scooped. I feel like the running like a freight train should have been my first clue.

That's what he feels like.  I rate, he actually rates, then just charges right through my hands.  LIke I'm not even there.  It feels like more than just his usual being strong.  He almost went through a fence last night in a time only at 2nd.  Just flew straight behind the barrel.  He's a kind boy and he IS strong, but I feel like this is something different.

I would work him ( at the speed where he has problems) and immediately get him scoped. He might have a flapper or soft palate problem, other than bleeding, that is making him panic.