Breaking Stride @ Canter- Need Help!!

Alright, I am having issue at the canter and need some help. So heres some background info, my gelding had a rough start as a three year old, trainer couldn't ride him anymore and he was thrown out to pasture for two years. I got him and restarted him, worked the bugs out and got him to a pretty good point. I've been riding him for almost 2 yrs, done shows with him and he has always done good.

This winter was really bad, and I didn't have an indoor place to ride so he was off for eight months until the weather got better. I started in later spring and he was doing great, no serious issues.

But recently he has begun to do something I find very odd. When cantering on the left lead he will canter for a while and then do a regular canter stride with his front legs, and switch to a trot with his hind legs. Since he can only do one stride like this, afterwards, he breaks into a fast and stiff trot. Which is unsual, because he is a very supple horse and I always do bending excercises before & after I ride. I've had my mom watch to make sure that's what he was doing, and not doing a funky crowhop or something.

He has been checked by a vet & chiro and declared sound.

I need some advice, I'm taking him to the county fair in about 11 days :/

Any way you can get a video of your horse doing this?

Kinda sounds like cross-firing in the back, which may explain why he can't hold it afterwards, but that's just a guess.

I, too, would like to see what your horse is doing. If you have had qualified professionals rule out pain, I would work the horse in a round pen and see if he is doing the same thing without a rider.

I am also betting that you have a horse that has gotten in the habit of 'dropping' a lead behind. If you let them drop on down and do a simple change back into the correct lead, you only perpetuate and reinforce the problem.

I have had quite a few horses that had learned to 'cheat' this way. It is easier for a lazy horse to do that than work harder by keeping its hind end up underneath it where it belongs.

I usually counter it by spurring the horse hard enough to MAKE it catch up with the hind leg that has flopped out of lead. In the left lead, it will be work to spur the horse on the right side behind the girth to keep its hind in up under it and keep its left hind leg to the inside where it cannot skip a step.

Teaching and demanding proper collection where a horse has to use its hind end correctly and teaching it to bring it hind end in to the inside for proper lead departures will prevent this and will correct it over time. When a horse 'uses' its hind end properly, it will stay correct and honest.

The other thing you need to watch is to not canter endlessly or to ride mindless circles. Challenge a horse with transitions, turn-arounds, stops, back-ups and as many other 'change-ups' as you can to keep a horse alert and listening and well-balanced. Keep a horse 'using' its hind end keeps it 'engaged' and it does not learn to cheat or drag its butt around like a little red wagon.

Thank-you for the advice, and I will try to get a video this afternoon, that is if my computer will let me upload it.

Oh, and about the hind end staying under him-
That may be a source for this issue. Last summer I was taking western lessons with a reiner trainer who told me that he works well in the front, but sort of "forgets" his rear end.