Cantering Your Gaited Horse
In the videos above you can see how one client progressed with her horse's canter, he is 10 years old and could not canter on the left lead. The first video was in july 2014 and the second video is from may 2015. So even an older horse can learn to canter, but it takes a lot of practice and so much patience, but the reward is so worth it. 
Everyone talks about it, but no one really gives you an answer do they?  How do you get that rocking horse canter, that all the gaited horse  websites talk about. You've been trying but your horse just won't do it. Or he canters well on trail but won't canter well in the arena. Well, some have it and some don't, its that simple. its in the breeding. Just like their flat walk and running walk and head shake, some gait easily and some just pace because its in the breeding, but it is also in how they have been ridden. So you can improve what they were born with, but you can't make your horse shake its head if it doesn't have the shoulder movement and you can't make it do a rocking horse canter if it's not built to do it. Put it this way, I will never run fast, I wasn't built for it, its not in my genes and even if a mountain lion came, I would run faster, but all my friends would pass me and I would be eaten. It's that simple.
So your still not sure are you. Well take your horse and roundpen him. Can he canter in the roundpen? Does he even know what you want? You first have to get them to canter in the roundpen, on the correct lead, in both directions, relaxed and calm and then you will be able to see what your horse has the natural ability to do.  This could take you weeks if he has never cantered, he has to build up the muscle first. If he just paces you need to drive him faster into a canter and then when he does canter a couple steps, relax and let him come back to a walk so he understands that was the correct answer and work up from there.  He must be able to canter without you on his back well, before you try it undersaddle. Make sure when you ask for the canter in the roundpen, you say canter, or cluck twice or kiss etc. so he has a cue for the canter. Then when you ask undersaddle, give him the same cue and ask with your outside leg, once he canters, only go a couple of steps and come back to a walk and relax, so he understands that was the correct answer. As you progress, then work on cantering in a large circle to help balance and slow the canter down. 
 If this is too much work, then take the quick way out and spend the money and buy one that already does it. Thats why the really good ones are expensive, they've had the breeding and the training to get there.
I have taught many gaited horses, to canter. From the young to the old and the older ones are not easy to do, but if you do it right, they will learn to canter and yes over time they will get better and better. In the process you and your trainer if not familiar with the gaited horse, will feel some odd things in the saddle because these horses will trip as they are learning, cross canter, bunny hop, pace canter and do all sorts of funny things while you are teaching them. In the beginning it may even make you want to be sick, but over time with practice and building of their muscles it will get better, that is one of the reasons, why you want to teach them to do it well in the roundpen, so you dont get sea sick in the saddle.
Look at the videos below and see how each horse naturally carries itself in gait and at the canter. 

Not all gaited horses canter the same, some are more upright and have the rocking horse canter, and some are flatter and have a nice canter but it is not what they call the rocking horse canter and although comfortable, it feels totally different. If you want that rocking horse canter, you need  a horse that is built upright, these horses are usually narrow, higher headed and more lanky looking. When you take a quick look these horse look like they are all leg. The horses that have this canter will naturally canter like this in the roundpen, once the horse is relaxed, watch his canter, if he raises up with ease and can go slow, then you will be able to get the canter under saddle. If the horse is low headed and flatter, he will have a flatter canter, no matter how hard you try. 
How to Teach Your Gaited Horse to Canter- $20.00
is available on my DVD page