I got a long text message from the trainer last night, and it's very exciting news. She and Pie had a major breakthrough. Pie had been exhibiting two things in her early work with him that I'm familiar with - his forward wasn't really there most of the time, and then he would have moments of extreme spookiness and worry. Sort of an odd combination of shut-down alternating with loss of emotional control. We suspected that some of this might be related to my accident last June, when Pie was probably pretty scared by my falling off and the fact that I wasn't available to comfort and reassure him afterwards.
It turns out that we were probably right about that - as the trainer has been working with him more consistently and asking him to move more, some interesting things have showed up. She was working with him on the lunge yesterday - they were working on canter - and after a short time he just wasn't able to do it. Here's the breakthrough - he wasn't breathing well and therefore didn't have the oxygen to sustain the work. This would explain the sluggishness and lack of forward - he just didn't have enough air to move well. Some of you who've been following for a while will remember Horse #8 from the 2009 Mark Rashid clinic - the horse that couldn't breathe. His story has some similarities with Pie's.
Mark said that horses, like people, carry unresolved tension and worry from traumatic events in their bodies as well as their minds. And the horse has to move, and move well and vigorously, to dissipate that tension - otherwise it just stays locked in there. A horse that is tense and worried will not breathe well, which will inhibit the horse's ability to move and therefore the tension is retained. This issue often shows up at the canter - a horse that isn't breathing properly at the canter just won't be able to keep going. It's sort of a vicious circle - the horse is tense and therefore can't breathe properly so the horse can't move well enough to dissipate the tension.
A horse that is breathing at the canter should exhale once per stride - the horse's anatomy is set up for this. A horse that isn't exhaling rhythmically at each stride isn't breathing properly and there's some underlying tension/worry there that needs to be resolved. Pie's breathing at the canter was irregular - not every stride - so it was natural that he couldn't canter well and got tired easily. A horse that isn't breathing properly at the canter also won't have a balanced, rhythmic canter - the ragged breathing interferes with this.
The way through this, which Heather did with Pie and I've seen Mark do with other horses, is just to keep the horse cantering. This requires the horse to "unlock" to breathe properly - the horse, to get enough oxygen, has to start breathing every stride. Once that starts to happen, the rhythm of the canter together with the breathing allows the horse to move properly and sufficiently to dissipate the tension carried in the body.
These positive effects on the body then can help with the mental tension - in horses body and mind are really one. The trainer worked through this with Pie in both directions at the canter, and she said that once he started breathing properly his posture and movement completely changed for the better, and that Pie was relaxed and happy when they were done. She says this is likely to be a big turning point for him - she's pretty excited and so am I!