As a board certified Animal Chiropractor I often see horses that drag a toe and or swing a leg out to the side along with short stride, sound familiar?
Understanding some of the mechanics of the horse will give you some insight to the cause.
Lets first start off with the dragging toe. Your horse’s pelvis pivots with each step and this movement all occurs around a joint called the sacroiliac joint. When the sacroiliac joint is locked in a downward position it makes the hind leg on that side act as though it was longer than the opposite side. Thus your horse will have difficulty bringing the leg through resulting in toe drag.
Rear leg swinging outward likewise can be attributed to a dropped sacroiliac on the same side. The horse will endeavor to bring the rear leg forward by swinging it outward first since the brain will interpret this side as longer and thus stimulate muscles to swing outward.
Short strided gait will occur on the opposite side of the long leg since the brain will interpret a shorter leg and thus not bring the leg as far forward. There may even be a sacroiliac joint locked in the upward position on this side thus simulating a short leg.
What to do about all this you ask……, well having a equine chiropractor evaluate your horse in concert with the farrier and vet will give you a leg up on the matter [no pun intended]. If in fact there is a movement problem within the pelvis along with muscle tightness then the chiropractor can adjust the sacroiliac joints and any other compensating joints. Exercises and muscle work will also be utilized to help.