For some reason, cantering under saddle has seemed to become a problem with my horse. She is now 7 years old and I have had her for about 3 years. Her "good" way is the right lead, I think because she is blind in her left eye and going this way she could see me while I was round penning her. She would go fine when I lunged her, but as soon as a rider got on she would turn into the center, buck, crowhop, etc. Eventually I got her to go comfortabley that way when I rode her, but the other direction was the problem. She would refuse and pull the same tricks she did while going the other way when we started, except she still is troubled. I don't think there is a pain issue because she has done it quite well before (on those good days, but after that it was back to square one). Now she will attempt it, but most of the time she just won't pick up her left lead. My coaches taught me to put my outside leg back when asking for a canter, but if that is wrong please tell me. I think that she does that because when she picks up the wrong lead, I bring her back to a trot and then try again and keep doing this until I am completely out of breath and then stop for a minute, so she gets out of work by doing this. It gets so frustrating sometimes, and I'm not quite sure what to do. If anyone can tell what I am doing wrong from reading this, or have any suggestions they would be much appriciated.