Sour is my three and a half year old miniature horse, who I am training to pull a cart. She lunges on cue (woah, walk, trot, canter, switch), ground drives (with a halter, though she does bridle. Still working on giving to pressure at the mouth and poll) and backs on cue, but we need to start working on getting some consistency into her trot. She's got a lovely carriage trot, but will only keep it up for short amounts of time. Now I know that this can have to do with conditioning, and so I've done a LOT of prep work to establish as much of a top line as possible, and to get her moving off of her butt and not her forehand...which was harder than I thought it'd be without being on top of her! She has remarkable balance...always has. But she just gets lazy after a few minutes of trotting, and will slow down considerably and drag herself around.
How can I keep her going at that nice, floating trot- rather than the shuffle she wants to give me? I've tried giving her a nice little tap on the butt, but she tends to jump forwards- no matter how lightly I do it- and wacks herself in the mouth (hence me NOT using the bit yet. I don't want to ruin her mouth), speeds up for a few seconds, and settles back into her lazy jog.
I'm not even sure she realizes she's doing it sometimes- because she just sort of drifts around at varying speeds. What can I do to correct her? Should I have cue words for speeding up or slowing down within the same gait such as 'easy' or 'hurry' and reinforce it with my driving whip? Should I try investing in some rhythm beads? (please, no ads to sell me one. I want honest opinions on whether it will even work.) I think the rhythm beads might help, personally, because I'll be able to easily tell when she's beginning to slow- and I can fix the problem as it's happening, not after she's already slowed down considerably. Or should I just give her time? We've been ground driving for a little over three weeks, twice a week.