So, knowing the background about his personality will probably help you to understand or maybe provide insight into why he is balking at the canter.
He has a very large bouncy trot and for the last month or so I have been working with him on collection and coming into more of a WP trot with figure 8's and walk/trot transitions. Well, we finally got there and so I figured that I could move up to asking for some collection at the canter.....but he is stubborn and is hard to get into the canter and when he does he only goes a few paces before dropping back into a sickening gut wrenching trot. I haven't really asked for a canter in all of the time that we had been working on walk/trot transitions....did I make him forget??
Anyways, When he breaks the gait I will bring him to a walk and ask him to go up into a canter again. I am currently riding with a crop...dont want to try spurs at all! I can almost see the wheels turning and he is thinking of ways to avoid expending energy.
Then I read on another thread here that it would be good to practice transitions on the lunge line. He is reluctant to canter on the lunge but when I show him the whip he realizes he has to listen and gets pissed and starts bucking and kicking (which I can handle) and then finally after doing several loops where he is MAD and kicking and farting and rearing...he will finally give up and do a nice canter.
The lunge line sessions always start hard, he doesnt seem to be more compliant with repeated exposure and when ridden he still isn't willing to go up into a canter, we hadn't had THIS particular problem before. I don't think it is soreness or any kind of issue of him being sound.
PS- He will do a canter without any urging or cue when we are doing barrels. Have to share some photos of the big guy :)