Debuted at PSG in spring but scores weren’t quite where we hoped for as Canter Pirouettes are soo green for both me and horse. So rest of Spring and Summer only my trainer schooled the canter pirouettes with my horse. Trainer and horse can now do nice pirouettes (1/4, 1/2 & full); trainer still says she has to micro manage every step but horse understands them better now. So I got to start trying them again and we started with 1/4 canter pirouettes , which felt way better than in the spring. But when we started to try and go beyond the 1/4 toward a half in one direction (the left) - I either loose the bend or the haunches; if I get one I sacrifice the other 
To the right I most times get a decent schooling half pirouette but occasionally loose bend or haunches, but its more subtle and only occasionally. Horse likes to drop right should in a lot of movements and the left half pass bend is a bit hard for me to get just right, but can manage both of these mostly, but its apparently much tougher in Canter Pirouettes. Not sure what I am doing wrong. We can do very nice walk pirouettes but I do always have to remind myself not to lose correct bend. Wondering if anyone has had any light bulb moments or figured anything out to help with this type of issue. Thanks for any hints.
My trainer has me working all the time to manage my horse’s left shoulder. And I mean all the time. We also work to shorten and lengthen the stride on a straight line before schooling any piro. If you can’t get it on a straight line, you’re really rolling the dice to try a piro.
How are your half passes? How are your corners? I find all the building blocks need to be solidly there before the more difficult movements happen.
Half passes are good as long as don’t ask for too much bend (enough but not too much my trainer is always saying). If I ask for too much I lose the one shoulder; its a fine line there and I think that is part of what is happening in Pirouettes
It sounds pretty normal. Most horses IMO are less coordinated with the left hind - this would explain the R shoulder dropping in and the diff with L CP. There are tons of exercises. Since your walk pirouettes are good try going from WP to CP bake to WP.
CPs are hard as so many parts of the horse change. So by the time a trainer sees something to the time they can say it, that moment has past. It’s helped me to break the CP into little basic bits.
OP - I’m sooo not an expert at these, but when we were schooling my mare (and me) my trainer would make me come off the corner onto diagonal at the walk, pick up canter and basically immediately start the piro. I think the idea was that when going from walk to canter she was between my aids evenly and starting from a collected canter on stride one, by stride 2-3 we were turning.
This started us out in balance and not having to deal with bringing the canter to a small place. Essentially taking it apart as much as possible.
I do the canter pirouette like the TOH - same basic cues. How is your TOH? Do you use your outside leg to block the haunches from swinging out? Do you weight your inside stirrup?
I started (when learning them) with a square at the canter - getting progressively smaller until turns were the size of a dinner plate 
Thanks All! We are doing a bit of what everyone has commented on. Patience and Perseverence now :O)
I school them from the walk pirouette sometimes. Just ask for the canter, and turn, keeping your body to the inside and make sure to look around the turn. Another way to school them is to do a small circle first in shoulder in, then haunches in, then turn that into a schooling pirouette.
If you want to post a video, I will tell you exactly what is wrong. It can be a number of things, so pick your poison:
- You have not learned to ride the suspension of the canter correctly, and are leaning forward;
- You are failing to maintain the rhythm of the collected canter, and are holding your breathe;
3} You are placing your outside leg too far back in some misguided thoughts on controlling the horse’s hindquarters;
4)You are not maintaining correct weight in your outside stirrup; - You are riding with your stirrup leathers too long and reaching for your stirrups…which means the weight of your foot on the stirrup is on the front edge of your stirrup instead of the back edge (as also happens when your leg(s) are too far rearward.
- Your mare has not really learned how to collect properly, and is still on her forehand by too great a degree, and this goes back to your canter seat.
