As far as resistance to turning, I would want to rule out or treat any possible pain issues first. My recommendation would be to have Kahlua examined by an equine chiropractor for spinal or skeletal misalignment, an equine massage therapist for deep muscle tissue problems and an equine dentist. You'd be surprised the variety of behavior problems that have their root in dental problems. This should be handled by a certified Equine Dentist who uses power tools, not just a vet with a rasp. There is much more to equine dentistry than just floating the teeth.
After that I suggest you perfect the turns at the walk first then the trot before going to the canter. Put four cones or markers in the arena forming the corners of a large square to make 90 degree turns around the outside of the square. The markers give you and her focus points for turning. Ride the square and make a right turn at every marker until you've ridden 10 times around then switch to left turns for 10 circuits. With this repetition you'll be "grooving in" your turn signal like a golfer hitting a bucket of balls on the driving range. Be consistent with your focus and body language in the turn signal. Use the "3 part turn signal". For a good review of this turn method you may want to read my article which was in the Nov. issue of Perfect Horse magazine: http://www.myhorse.com/training/western/turn_signals.aspx?ht=#topAlso I've attached my hand-out on the Laws of Rein Effect which may be helpful. The nose is tipped in the direction of travel with your inside rein then your inside leg is off the horse stepping to the inside of the turn with 40% of your weight in that stirrup. The turn is cued and guided by the outside rein laid on the neck about half way between the withers and the ears. The outside rein hand should never cross the mane, otherwise you would be pulling on the outside of her mouth and wanting her to turn to the inside at the same time thus a contradiction in communication. Your outside leg should support the outside rein by touching with your calf up front toward the cinch to "talk" to the shoulder so the shoulder follows the nose. Keep this cue on lightly no matter where she goes in the arena until she finally breaks the shoulder over and follows her nose. Don't kick or push harder with the rein, just stay steadily asking for the turn until she complies even if she wanders all over the arena at first. If she resists your light cue she will probably end up at the fence and the fence will help you make the turn. That's ok, she will realize that there was no profit in resisting because one way or the other she still had to turn in the direction you first requested. Be relentlessly consistent with this and she will start listening sooner to your light outside rein and outside leg. Be sure to keep her looking in the direction you want to go by using your inside rein without much bend in the neck, just so you can see the back of her inside eyeball. The inside rein does not ask for the turn, it only asks her to look in the direction of the turn. The turn belongs to the outside aids. When moving the shoulders in the forward turn, the horse should always be guided by the outside aids not pulled by the inside.
Enjoy the Journey,
Ed Dabney is an internationally acclaimed clinician, presenting horsemanship and riding clinics all over the US and in Europe. In 2007, Ed was named Champion of the East Coast Trainer Challenge Series by Equine Extravaganza. Ed was honored to have been selected by the University of Georgia to teach their senior level Young Horse Training course.
His training articles have appeared in many major national magazines. Ed produces instructional videos and the “Gentle Horsemanship” TV program which has been seen on RFD-TV.
Ed's blending of natural horsemanship and classical equitation has made an indelible mark with students all across the United States and now also in Europe, drawing the attention of serious riders searching for the lightest touch and the deepest connection with their horses irrespective of breed or discipline.