Perfect symmetry is rare in nature. “For instance, I’ve seen some figures that showed about 80 percent of the human population have a limb length disparity. It’s more common than people realize, in horses as well. It’s difficult to shoe these horses as a perfectly matched pair. You generally need to assess one limb at a time, and an important factor is just reading the hoof capsule — the bars, coronary band, wall separations, sole plane, and looking at the white line and frog (ground contact),” says Mitch Taylor.

"To me, sometimes the hoof/pastern axis is not as important as other factors regarding how the foot is interacting with the ground — that might be more crucial than a straight hoof/pastern axis,” he says.

The farrier is always making value judgments and looking at certain priorities. For instance, a back problem or a shoulder abnormality can contribute to discrepancies in limb length and stride length, making one foot more upright. Taken to extreme, one front leg may develop a club foot.

“If I need to correct an issue like that, one of the things I’ve learned in studying high-speed videos is that toe length and breakover isn’t always as critical as I once thought. I don’t always need to back the toe up as much as I used to. I determine when and how much to address the toe by reading the general health and integrity of specific areas of the hoof capsule,” he says.

Equine athletes are judged on many different criteria, and these will often determine how individual horses are shod. “For most sport horses, assuming they are sound, I trim and shoe each foot according to that foot/limb’s conformational proportions and balance points, and not worry so much about making the feet a matched pair. Comfort and a free-moving horse are the top priorities. Events like flat racing, polo, rodeo, eventing and jumping are examples. Other disciplines may require a more symmetrical gait to do well in competition. For instance, Saddlebreds and other gaited breeds, western pleasure and hunt seat horses need to have the same knee and hock action on both sides, with equal stride lengths,” explains Taylor.

Individuals with mismatched pairs of limbs and feet that compete in those events often have a different arc of flight or stride length, and might need help from a farrier in fine-tuning the gaits. It is important that farriers don’t over-trim feet to make up for these limb/foot differences, however.

“What I can’t correct with the trim, I correct with the mechanics of my shoe. In situations like this, I feel that shoe stock dimension, weight and placement can help square up legs and feet that are not matched pairs, or that have faulty conformation. Often I use some vertical markers on the side view of a foot, to reference the points of breakover and heel position between feet. I’ll draw a straight line down the side of the foot from the extensor process, and measure the distance from that point to the toe and heel. The object is to get these distances the same for each pair of feet. Any variance of these measurements between pairs of feet can usually be equalized by using different shoe stock dimensions or lengths, and rim pads if necessary,” he says.

Norman says shoe style will vary depending on the horse and his work, but you still need to support the foot according to the horse’s conformation. “Horses rarely toe in on the hind feet, but are still putting a lot of pressure on their heels, especially at a young age. They toe out and put a lot of pressure on the inside quarter, but as they get older they are often wearing the outside heel — especially the racehorses — to the point where you have to support the back part of the foot to reduce the trauma,” says Steve Norman.

“On hunter-jumpers a lot of farriers are fitting the outside heels very full or even adding trailers to support that outside heel and/or help the horse travel straighter, giving maximum support to the horses that tend to have a conformational breakdown. You can often get by without doing this, but helping a horse travel straighter and with more support will generally aid his performance or speed.”

If you can reduce any wasted motion or eliminate an interference problem, the horse will always do better. The horse that hits himself may crack or break a bone in the opposite limb, or may just become sore enough that he won’t perform at his best.

“It’s amazing how much difference a tiny bit of correction will do; it’s just millimeters of added support that can help that horse travel better or have less wasted motion so he finishes his race better or has enough energy to head or catch that cow or give his best performance in whatever job he’s asked to do,” says Norman.

“Some people get very elaborate in the shoes, but my favorite quote is from my mentor Jack Reynolds. ‘Keep it simple’. People would ask him to come look at a problem horse or correct this or that, and they’d already gone through x amount of horseshoers who tried to correct it. Every time, his thought was to un-correct everything and get it back to as natural and simple as possible. It worked for him, every time,” says Norman. The more elaborate shoe you add to the foot, the worse you make some problems, aggravating any deviation in foot flight.

You have to figure out each horse, and how best to shoe that horse. Some don’t fit the textbook rules. “You have to be open minded on every horse that comes to you. You often want to do what worked last time in a similar situation, but it’s not that easy. It might be different for the next horse,” says Norman. You have to determine, on an individual basis, how much support and protection to give the foot. “You don’t want to give too much or it will alter the foot flight adversely. If you support the inside too much, the horse will interfere.” You have to sometimes use trial and error to find what works best for that particular horse.

“There’s a huge barefoot movement today, stating that shoes are dangerous and detrimental for the foot,” says Taylor. “And yes, they are, if put on irresponsibly and with poor technique. But if there aren’t problems in technique, a shoe can be very helpful in correcting a horse.” Proper shoeing can definitely help resolve a foot problem.

It can also help if the person trimming/shoeing the horse can see the same horse over a long period of time. There is a great advantage to becoming very familiar with a certain horse, to know how it moves and what needs to be regularly done to optimize normal movement.