Patty Stiller CNBF, CLS

copyright 2008  

Introduction

I began my career as a farrier back in 1982.  In farrier school I was taught the traditionally accepted principles of horse shoeing, most of which had been in use for several hundred years. These principles had been”updated” over time, as new studies and ideas about the mechanics of the equine foot were made available.

I used these principles from the time of my graduation from farrier school in the early 1980’s until the mid 1990’s. I did  the best I could treating common equine lameness and trying to prevent it. Some lame horses got better, a few never improved much despite ”doing everything possible ”.  Conditions such as “navicular syndrome” seemed inevitable in some horses due to conformation, breed or use. The gradual worsening of navicular syndrome in horses was accepted as the usual progression, and deemed inevitable. Farriers never imagined or blamed themselves for causing it.  Most chalked it up to poor breeding, conformation or use.

Treating those cases became more and more frustrating, as the shoeing protocols that I had been taught were applied and would offer some relief for a while.  Inevitably the lameness would gradually worsen again, and more radical shoeing would be needed until finally the horse would be deemed  untreatable and end up with a neurectomy to cover up the pain,  retired, or euthanized.  

As well there were those horses who were just never “quite right”. Those who were maybe not obviously lame all the time but a little “off” especially when turning corners .  Vets would do diagnostics and X-Rays and never really find an exact cause.

Then something happened in late 1995 that changed my entire outlook on preventing and treating lameness. The event offered me some new insight about the root of many lameness problems.

I was asked by a veterinarian to attend a demonstration and lecture by Gene Ovnicek, who had conducted hoof wear pattern studies in feral horses and was discovering how applying that information might benefit domestic horses.  At that time Gene was considered radical in the hoofcare industry because his ideas were challenging some of the traditionally accepted principles about farriery which had been in place for many decades.

The questions that arose from these feral hoof studies opened the door for more research from scientists all over the world about the problems in domestic horses’ hooves. It was just the beginning of a new look at how to better manage hooves. 

The advent of high tech research techniques for equines including  “MRI”, computerized loading, kinetic and movement studies, as well as computerized  joint and tendon stress studies and new techniques in cellular studies began to reveal a bigger picture of  how “off track” we were in some areas of our understanding of the domestic equine hoof.  

The most encouraging thing is that we now know is that a large portion of foot lameness in horses comes from abnormal stresses placed on various tissues due to internal misalignment of the joints, and improper foot landings. We now know that a large percentage of foot lameness is centered in the connecting structures of the coffin joint and navicular bone, particularly the ligaments, and that by the time lesions are seen on the bone itself these problems have been going on quite some time.   The connecting tissues (tendons and ligaments) around the bones are the first to be impacted by abnormal stresses and poor footfall, then the bones eventually takes the brunt of that and suffer deterioration.

Sound horses land flat to slightly heel first, and load the back of the frog at the same time as the heels.  The importance of that can not be over emphasized. The frog and other internal support structures help align the bones correctly upon impact. We now know why a horse may land toe first, and how to correct it.  Although it is very complicated, it boils down to the fact that most toe first landings originate from poor internal hoof imbalance.

The practice of shoeing to the very end of the flat trimmed toe with a flat shoe unfortunately often leads to these various internal imbalances.

As well the practice of trying to ”grow more heel” on a foot is extremely destructive because it allows the heel to run forward under the foot, which then leads to internal bruising and heel pain. And by allowing the heels to grow too far forward under the foot, the outer foot loses its relationship with the bones inside, setting the ground surface (the footprint) too far forward under the leg.   That creates a tremendous amount of stress on everything inside the foot with every step the horse takes.  He also can not get his foot off the ground in time with the rest of his body so he has to shorten up his stride and land toe first.

 In some domestic horses there is an internal weakness which causes a front to back misalignment of the coffin joint,(“broken back alignment ”)  leading to pain in the tissues under and around the navicular bone, and eventually the destructive shortened stride and toe first landing.

Whether from an inherent weak foot or imbalanced shoeing, the scenario may go like this: first a toe first landing, which then leads to damage to various internal tissues, which then leads to pain in the tissues around the navicular bone (“navicular syndrome” ) which then leads to the horse deliberately shortening his stride and landing more toe first, leading to more  internal foot pain, and so on until eventually he ends up with a diseased navicular bone.

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We also now know that a lot of lameness in performance horses originates in the coffin joint and the two ligaments on the sides which connect the coffin joint together (the collateral ligaments). Side to side (medial-lateral) imbalance, as well as stress turning corners are major causes. Horses’ foot joints are simply not designed to turn a lot of corners, especially at speed. And we ask out modern horses to turn tight corners all the time.

Newer anatomical studies have shown that the traditional way of trying to balance the foot medial laterally by sighting down the leg can be very misleading. Studies done on the sole have shown that carefully following the sole of the foot is much more accurate to balance the coffin bone to the ground and evenly load the coffin joint. 

Then let’s look at the symptoms of a medial laterally  imbalanced foot. It may show up first as a vague shortness turning one direction, then reluctance to take that lead, then reluctance to perform at all until finally he begins to show visible limping.

 So to summarize the sources of the foot problems,  it is heel pain, internal imbalances, stress to the coffin joint and collateral ligaments, and an outer foot that is no longer centered around the bones which cause a cascade effect that eventually can lead to most common foot lameness issues found in today’s horses.

So here lies a question. Is the toe first landing the cause of the lameness or the symptom?

 The answer is that it doesn’t matter when treating the horse.  Just fix it.

The treatment goals are fairly simple. Fix all the causes.

That comes in five steps. How exactly you apply the steps is individual, but the principles are the same.

 1) Properly trim the foot. Get overgrown heels and bars trimmed back to remove the abnormal pressure that causes bruising, and to move the back part of the “footprint” back where it belongs. 

2) Properly balance the internal structures from side to side.  Follow the sole plane or get X-rays to insure that you have achieved medial lateral balance.

 3) Properly center the outer foot around the coffin joint. If the horse is to be left barefoot this means placing the “breakover point”, or the place the foot pivots over the toe in the correct place relative to where the bone is inside by rasping the bottom of the toe to rocker it . There are means to map this placement out without X-rays which are very accurate. ” If shod, this means centering the shoe around the bone the same way.

4) Insure a slight heel first landing.  Most horses will go back to a heel first landing as their comfort level increases with the first three steps. Those that can not will need artificial help to achieve that, possibly in the form of artificial frog support materials, wedges, etc at least for a while until they heal. Mature horses with inherently weak internal structures who can not align their own coffin joint bones may always need some help.

5) Insure that there is eased turning, allowing the foot to roll over in any direction, tipping into the ground easier as the horse turns. This can be done in many ways and at the very minimum, if shod it means using a shoe with a rolled edge. In treating lameness from collateral ligament or coffin joint damage this can be enhanced more with many modern hoes designed for this purpose.

Soft tissues such as tendons and ligaments have the ability to heal if not too far damaged.  Therefore a lot of “navicular syndrome” and vague coffin joint pain may be curable. However if the destruction has gone on too long, some things may never heal to the extent that the horse will go soundly without his man made help.

The good news is that we can actually cure so much now than ever before by understanding and removing the causes.

Even horses with tissues that are far damaged to totally heal can be kept so much more comfortable in their jobs despite the presence of that damage, who would have been given up on and either retired or destroyed not too many years ago.

And we have only touched the tip of the iceberg in understanding and treatment. There is more to come in the future.

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