mare not wanting to trot

Question
Hi, my name is Heather and I am 15 years old. I have owned my own horse for 3 years now, and I do pleasure riding and some jumping. Recently when I have been riding my 16 y/o arabian mare, she has been trying to move into a canter whenever i ask her to trot. She is very highstrung. If we are walking and I give her the cue to trot, she will canter in place some and then try to move forward in a canter. She has only done this recently.I would like to be able to have fun safe rides with her, and maybe show some this summer. How do I get her to trot? Thank you!

Answer
Dear Heather,
Could you please give me a little more information?
You say that you have owned your own horse for three years- is this the same horse of which you write? If so- you you mean that in all of the three years she has never displayed this behaviour?
I would begin by making sure that there is nothing physically bothering her: teeth, new saddle, back sore etc.
If she checks clear- does her behaviour coincide with her heat cycles?Is there a new gelding or a stallion in the vicinity that might be triggering her actions?
If none of this pans out- begin your sessions with a good 20-30 minutes of lunging- both directions- walk trot and canter. If you have a surcingle and side reins- use them.
Once you mounted- do lots of circles and transition work at trot. If she breaks to canter- let her go forward and circle- spiral your circle down smaller and smaller and then ask for trot. Spiral your circle out at the trot and then take up the outside track. Bringing her back to trot when she gets strong will simply begin a fight. Every time she breaks to canter- again- don't pull her back to a trot- just circle her.
I hope this is of some help.
Sincerely,
S. Evans