A quiet revolution concerning "corrective shoeing" has been occurring among farriers and veterinarians. These foot experts would like horse owners and trainers to know that the term "corrective shoeing" is inappropriate.
"'Corrective shoeing' implies we can do things far beyond our capabilities. We assume if there is a fault with the conformation of the horse, we have the ability to fix the problem. That's not always true," says farrier Bob Grover, treasurer and certification examiner for the American Farriers Association and consulting farrier for Ohio State University. "If the horse is born with a crooked leg, I can shoe that horse to make him move better, to make him feel more comfortable, but he still has a crooked leg. That is not 'corrective shoeing'; that's 'therapeutic shoeing.'
"In other words," Grover emphasizes, "you're either doing 'correct shoeing' or you're doing 'therapeutic shoeing.'"
What Is Corrective Shoeing?
Correct shoeing provides appropriate balance and eases the way the horse moves. The method is not a one-shoe-fits-all approach, but considers the individual horse, leg, foot, and balance, and applies a shoe for that individual.
"The keys to correct shoeing are balance - side-to-side, medial-to-lateral, toe-to-heel, interior-to-posterior, and hoof pastern angles. We look at establishing and maintaining support so the horse's foot is underneath the center of gravity of the leg. That is what the goals are as far as what is correct for the horse," says Mark Martinelli, former farrier and now a DVM and orthopedic surgeon, University of Illinois.
Through careful assessment of a horse, a good farrier can provide the animal with shoes that enhance his movement and balance. "We promote or facilitate the movement," explains Martinelli, "that is, allowing the movement to occur as easily as possible for the entire leg, including the foot, as opposed to trying to stop and change that movement at the foot level."
Variations in Corrective Shoeing
A variety of shoes can help balance a horse that's not off due to conformation or medical reasons. Rolled toes, with a rounded bottom along the surface of the toe; the rocker toe, where the whole shoe curves up and usually requires trimming of the foot so the shoe fits; and the square toe, with a squared instead of rounded toe, will ease breakover. Wideweb shoes can help with sole bruising or sole problems.
But, Martinelli emphasizes, a change in shoeing cannot perfect movement and balance problems caused by conformation; it merely shifts the trouble around.
"Once the horse matures and the bones and joints stop growing, whatever form they're in, whatever shape they're in, that's the way it will be. To change the way the foot is, the shape or the balance of the foot after the bones and joints are mature, is going to affect the stresses of that joint; that's where we start talking about problems with degenerative joint disease.
Adds Grover: "If the horse has a significant deviation, there is really nothing you can do. If the leg is bowed, you can't unbow that."
Shoeing that does not consider the horse's conformation and tries to force a "correction" can lead to lameness. So, too, can inappropriate shoeing on a horse without conformation problems. In fact, "correct" shoeing often means modifying someone else's mistakes.
"The most common problems with horses that don't have conformation problems, but have lameness, nonetheless, is usually because they have too short and/or too small of a shoe," says Grover.
Another common problem caused by inappropriate shoeing, says Grover, is when the "shoer or trainer/owner decides that the horse needs to have a higher angle, so as a result, the horseshoer leaves more heel to the foot. Over a period of time, it gets driven forward underneath the foot and becomes a fulcrum point for the horse to rock back on. Every time you leave more heel on the foot and just cut toe, you shorten the bearing surface of the foot."
For horses with medical foot problems, therapeutic shoeing often can help manage the problem. One of the primary keys is early treatment.
"The farrier sees the horse frequently and should serve as the first line of defense against lameness," says Martinelli. "There can be very subtle changes in the horse that may occur from one shoeing to the next or be occurring gradually over a 6-month or year time period. The foot can be changing in shape or balance, and that can be a key that something else is happening, that the horse's leg or foot is causing an imbalance to form.
"If the heel is growing longer, if the foot is becoming sloped on one direction, if the frog is becoming atrophied and shrinking, we need to step back and learn if the horse is doing it, if the horse is changing the way he's moving or bearing weight on the foot or leg because of another problem," Martinelli says.
Careful analysis by the farrier and a veterinarian is needed to diagnose why the foot is changing, why the horse is experiencing imbalance and why the horse is sore. After the diagnosis is made, the next consideration is what can the veterinarian or farrier do differently that will help or manage the situation. Here are some typical problems that can be tackled with theraputic shoeing:
"Probably the classic problem we deal with is the underrun heel," says Martinelli, "where the heels are starting to grow farther forward and the toes are starting to grow farther forward out in front of the horse, instead of being more supportive and underneath the horse. We try to establish a more normal hoof axis and try to establish support through the heel of the horse's foot, to reestablish the support underneath the center of the gravity of the leg. One way is through trimming and shoeing."
Bar shoes, which take a normal shaped shoe and apply another bar of steel running across various points, are commonly used in such cases, as they provide support and protection. Eggbar shoes, which are round, establish heel support.
Doing the Right Thing
For the horse owner, it's often difficult to tell how a horse should be shod, balanced, trimmed, or even if the farrier is doing an appropriate job. "If your horse is not lame, you have to assume there is nothing wrong for the time being. But if your horse needs to be shod rather frequently, less than 4 weeks, there is an indication that something is not quite right. A good, honest shoeing job should last 6 to 8 weeks," Grover advises.
Finally, it's important to remember that corrective and therapeutic shoeing, like most physiological or medical procedures, is often an art and not always as scientific as we wish.
"Everything we do is risk/benefit," explains Martinelli. "As in forging, you can take off too much and then totally alter the way the horse moves. In every case, every horse's foot needs to be treated as an individual because you can cause problems with even the best of intentions."