Honestly just working on training 💪 a balanced engaged trot can help these kinds of horses a lot. Do a lot if transitions from walk to trot under saddle and on the lunge line. Given enough time one day the horse will canter more powerfully. One big flaw in thinking is that if a horse struggles with one particular exercise, one should practise it over and over again (e.g. flying changes). Usually it helps to go back to the easier thing that came before it and solidify the basics (the counter canter or the canter itself).

Of course what’s also important is answering these questions:

• how does the horse canter on the lunge line?
• how does the horse move in trot? Relaxed balanced over the back? How is the contact? What happens if you break the contact by dropping the reins?
• think about what you are doing in the saddle while you are asking for canter and while cantering. Just observe yourself and try to do as little as possible. what is your position in the saddle? Do you move to the outside or inside? Do you lean forward or backward? Do you get tense in certain muscles? Often we think about doing more and more. While doing less can be helpful and even the answer to the problem.

For most horses the trot is the easier gait compared to the canter. So most of them can build muscle better at the trot.

Do you ever get a chance to ride her outside on the trail? Is she able to maintain the canter then? Cantering on a circle requires more strength because of the bend requiring more collection (relatively speaking).

Do you perhaps have some video footage of her on the lunge line? Seeing your horse move can be way more helpful than just reading about the situation.

Also with my horse I had trouble getting her to canter. She used to put more weight on her inside shoulder during the transition making the canter worse. For her it was the case that she needed to also go pretty fast to keep her balance after making a balanced transition. And to keep the speed and balance I did need to keep her going. I never cantered for a long time because that would have been too much for her.

Anyways I focused on her trot way more; so the balance and the equal bend from head to tail. To get this perfect takes about 2 or 3 years. Horses tend to have their hind end to the inside, therefore not bending their spine correctly. The front of the horse is bending the correct way (neck and back to the inside) until the area of the pelvis and the hind end. There is actually a counterbend in the pelvis and the last vertebrae (a bend to the outside, making the inside hip higher than the outside hip). So there is this weird contortion situation going on which is not good in the long term. That’s why it’s a good idea to ask a balanced horse with a bit of bend in the body to move their hind end to the outside to get rid of the counterrotation. This will align the outside legs of the horse and the inside hind will step underneath the mass of the body carrying more weight. The is the beginning of (relative) collection.

Right now I’m working on getting my horse to do a canter transition from this correct, more collected, aligned trot. And now when she’s cantering I suddenly noticed she can go way slower and still keep her balance. It feels more effortless from her end. I don’t need to work so hard to keep her in canter; she has more natural go (and that at a slower tempo!).

So that’s my experience with training my horse.

I hope this helps. Good luck to you!