I recently read about a study that a group of vetrinarians did on horse stretching and was VERY suprised by the results. They took 3 groups of horses and tested how stretching changes the way the trot up(length of stride) and the flexability of the joint. The first group had nothing done to them, the second had stretching 3-4 times a week and the third had stretching done 6 times a week. The horses that were stretched 3 times a week proved to have an increase of range of motion in their joints but no difference in stride length. But the horses that were stretced 6 times a week had a DECREASE in range of motion in the horses stifles, hocks, and sholders compaired to the other 2 groups. This was suprising to me because of all the people who swear by stretching their horses all the time.
Stretch your horse. Its good for it. Well that's what I beilive my horses strides are so much smoother when I strech him out because nothing is too tight or pinching so she is relaxed.