I have a well pattered but green (very limited time off the place) 5yo that will switch or lose her correct lead leaving the second barrel.  She's fine on #1 and #3, but it doesnt matter if we're going right or left, she loses that lead coming out, pushing off to #3.  Any one ever dealt with this or have any tips/tricks to fix or prevent this from happening?  

Is she finishing the turn completely?

Is she crossfiring in back, or are all 4 legs changing to the wrong lead?

I would think that if it is a pain issue, she should also be having a problem on the 3rd barrel. But you say she's not.

Since barrel #2 is the "longest" turn, really make sure they keep that hip under them and not drift at the end.

Do you have a video?

No video, will try to get one.

There is a bit of a hesitation when it happens - if that's what you mean by finishing the turn?  She's not pulling off the backside or anything like that when it happens, almost like her back end is trying to keep up with her front.  If I overexagerrate and really try to keep her between my hands and not let her cut in, at a lope I can keep her in the correct lead, but when I cruz her through or ask for any kind of speed or just "let her work" she loses it.  But yes, it's definitely more of a crossfire or the hip drifting.  

Needs to be more broke.

I had this issue with mine when I first started him - he's big and was older and didn't really know how to handle himself. I set up one barrel in the middle of the pen, and go way out around it in a huge circle at a lope. Then I pick a random point and bring him in like I'm headed to the second barrel - make him do a perfect turn just like you're working second in the pattern - if he tries to blow off, drop his lead, cut in, or any other issue, he has to keep going around it, tight and quick, until he does it correctly, then he gets to go back out to the big circle. I do it both directions, but it's really been helpful for me for working out issues with second. 

It really teaches them to think about turning correctly all the way around the barrel and keeping under themselves, instead of just getting to a certain point that they think is the relief point at the backside and dropping everything. It works especially for horses with issues on second, since it's the most complete turn we ask them to make. 

It will take time as they gain exposure and confidence. My 5yo was doing that here and there and as we kept going and he's gaining confidence, it's no longer happening. 

This is what was happening to mine but it would just be random ... not a specific barrel.. it wasnt until I really got him legged back up and he learned,  well, re-learned how to get his hind end down and get the power coming out and going into a turn, my horse is built pretty downhill and it's not easy for him but hes capable when hes not just being lazy and strung out. After we've been roping again for the last few months he can turn better and not lose himself behind and I have to really sit to get the rate and turn ... because he will throw you forward. I didnt rope today but I decided to work on his turns around some barrels and theres a huge difference from how he was turning a few months ago. 

Where would you start trying to pinpoint soreness on something like this? Hocks?  Stifles?? The more I watch her move I'm wondering if that might not be part of my problems here

I just had a colt checked out because this same thing has been an issue for a while. First vet said EPM, we treated her 30 days and she only got worse. Went for a second opinion with another vet and she has pelvic issues. Her pelvis is off from an old injury, scar tissues and a big knot. It is pinching her SI, causing weakness in her hind end, cross firing, giving out, and some other issues. 

If she's not sore, sounds like she's struggling and just doesn't have the right muscles conditioned for that turn.

I would definitely start with some spiralling exercises, at a trot first. But always making sure to keep forward motion and the hip in (you'll probably have to really keep her "put together" as the circle gets smaller). she's probably just trying to figure out how to use her body and needs a little more guidance. 

That's my gelding signal to me it's time to refresh his hock injections. He switches his back lead to the right lead when he finishes the 2nd, runs to 3rd and changes it back to left lead to turn & then that it. When he's bad he'll start to do it running home too. Not saying yours is sore, but when it is soreness related it's always been hocks for me. 

I am usually the odd man out and dont jump immediately to soreness. I see this A LOT, and usually it a balance issue. It is a full turn, it requires a lot of physial fitness and strength to hold balance. I would be doing a lot of spirals and counter bending at the lope. Moving them right, left, engaging and disengaging, etc. I do believe they can get sore from not being conditioned correctly and obv always an option but I think its more likely the horse is young, inexperienced and trying to find its footing.

Straight Barrels exercise is great for this issue.

Can you explain this drill please??

**IF** it is a soreness issue, usually when a horse crossfires in back on the backside of the turn, it's stifles.

I'm pretty proactive, so I probably take mine for a lameness exam sooner than most, but I like the piece of mind of knowing that they feel good.

Sometimes with a young horse, it's just greenness .... and not soreness.