You dealing with a Tender Foot?

Is your horse a Tender Foot?

We receive at least three to four calls a week concerning thin soled horses. The stories have common threads running all through them. My horse has been tender footed for as long as I can remember. I have been trying to toughen his sole up for the past two years. Every spring my horse has bruised soles.

What it all comes down to is poor sole health, but why? We first need to look at the foundation for the sole. What is the structure that host the corium (sensitive structures, where circulation is present)? When observing  the "sole" most people refer to the area of the sole where the coffin bone is the foundation, the area of the sole around the apex (tip) of the frog. The horn that is produced by the corium covering the coffin bone is called "primary tubular horn." This horn is very hard, unlike the horn produced at the outer edge of the coffin bone. The horn produced at the outer edge of the bone and where cartilage is the foundation is called "terminal tubular horn", this  horn is tough and flexible. As a reference; tool steel (chisels, drill bits) is hard and unyielding, where iron is tough and flexible (pry bar, hinges). A benefit of being able to recognize and distinguish the difference between the two  types of tubule is gaining the ability to identify the location of the coffin bone within the capsule.  Each type of horn serves a purpose. Can you recognize the difference in the photograph below left?

The Primary tubular horn below the coffin bone helps in preventing torque / twisting of the bone and aids in establishing correct hemodynamic response (circulation), whereas the Terminal tubular horn helps protect against concussion and allows for proper distortion, this helping to protect the underlying sensitive structures and allowing for correct foot function.

When I hear someone say my horse has a thin sole they are most often referring to the Primary Sole located below (distal) the coffin bone and not the sole at its outer most edge (terminal sole). 

Why does this primary sole have such difficulty in growing healthy? There are several reasons, but the most common are a lack of proper circulation and excessive pressures on the corium resulting from a compromised suspension. (I am not simply referring to a lack of circulation, but rather to proper circulation and its timing). There are a number of causes for improper circulation to the solar plexus (vascular bed). One is improper conformation of the hoof capsule itself. You see, the foot is subject to the laws governing fluid dynamics and one law states that fluids always seek low pressure. The foot is subject to these laws simply because systolic pressure is superseded by the forces created by the stride, therefore blood flows from high pressure to low pressure throughout the stride. Having proper conformation of the hoof capsule becomes very important. To short of a toe for instance can reduce blood flow to the circumflex artery that partially supplies blood to the solar plexus. At the time of break over it is important that the toe be engaged, producing pressure on the outer wall creating high pressure in the lamellae plexus, thus causing the blood to seek the lower pressure presented in the primary solar plexus. If the pressure on the hoof wall of the toe and its corium (lamellae plexus) is not higher than that of the solar plexus then proper circulation may not occur. This is only one small part of how circulation (hemodynamics) occurs in the foot.

Overall circulation in the solar aspect (bottom of the hoof) can also be affected by a lack of suspension of the Internal Arch Apparatus (Internal foot). Lack of suspension results in chronic mild compression of the solar corium, which can cause bruising, abscessing, and poor horn growth. Where does this lack of suspension come from? Most often it is the result of  unhealthy Ungular Cartilages. The ungular cartilages and coronary band are partly responsible for suspension of the foot within the capsule. When ungular cartilages becomes unhealthy they suffer a loses elastic potential (the ability to resist distortion). When the suspensory structures suffers a loss of elastic potential the sole is the first place we see the symptoms. This is primarily because the internal foot and the relationship it holds to the hoof capsule are under the greatest amount of stress. How does this occur? Loss of Ungular cartilage health (poor development of extracellular matrix) is often the result of a metabolic disturbance of some sort. Following a harsh winter many horses can suffer metabolic imbalances due to seasonal changes in environment, dietary changes, and hydration changes. Spring can be very stressful for our horses. 

Hoof wall integrity also plays a roll in suspension of the internal foot. If hoof wall integrity is compromised by poor wall matrix, excessive moisture, or excessive trimming, distal decent of the internal foot can become excessive resulting in abnormal pressures on the solar corium. 

I suggest you take a close look at how environmental changes could be a cause of stress in your horse.

I treat thin soles by first addressing the metabolism of the horse, making sure the horse is well hydrated, trimmed properly, free of infection, and exercised to promote the health of the Internal Arch. Take care of the inside, to gain health on the outside.

Avoid the Pitfalls (Hoot to Foot Balance)

The more studies conducted evaluating balancing of the hoof, (one such study)  the more it becomes apparent that many of today's farriers could be setting themselves up for failure. The solution is to approach each hoof with  a clearly defined game plan.

To that end I thought it would be good to show how I achieve balance in nearly all hooves, this even though no two hooves are the same. The method for achieving balance has remained constant, with this method of trimming having been taught the world over for more than 15 years. 

What's exciting is that we now have additional tools to confirm balance, and to improve consistency. Keep in mind that I trim to achieve balance. I do not trim to go barefoot or to shoe, I trim to achieve balance, that is my goal. I developed and use the new DBH Level to check myself, this because even though I have a good eye for balance I still want to avoid the pitfalls that come with being over confident. 

The horse and its hooves are the world's best teacher of humility. If you haven't been humbled by a horse in sometime, now is a good time to initiate a humility check. How consistent are you in achieving balance?  As I get older I have learned that it is better to be humble than to be humbled. 

This method can be used by the farrier or trimmer for the purpose of shoeing or for going shoe-less. The method is not about preparing the hoof for a shoe or for barefoot, it is about achieving balance.
An added suggestion taken from a comment to a post in Facebook: Always watch and listen to how the horse moves before and after you trim.
My thoughts on tools: Tools used that aid in confirming balance should be viewed as an adjunct to our ever improving skills of observation, and should not be viewed as the only means to achieve balance. Tools are meant to aid us in our work, increasing our accuracy and saving us time. No skilled craftsman works without those tools that confirm their skills (rulers, levels, squares), why is it that with many farriers ego supersedes practicing due diligence.

Using DBH Level to establish Axis Plane

Hoof capsule balanced to the Foot's Axis plane

Using DBH Level to confirm Toe Plane

HPA

Balancing Act or Act of Balance

At our school and throughout my travels I am often asked, "How do I balance the horse with less than ideal conformation?" The answer is quite simple really, balance the hoof capsule to the internal foot.  

I have been teaching students for more than a decade to balance hoof to foot. I have gone so far as to have three or more students on one horse at each course. That's right, four different trimmers on one horse, with the end results being a balanced horse. 

I remember doing a clinic for a group of Amish Farriers in Pa. more than ten years ago. There were 29 farriers present. I had four different farriers trimming a draft mare. Each farrier would do one hoof following my direction for achieving balance of hoof to foot. As each farrier trimmed a hoof I noticed a slim guy with a long beard in the back of the group. He was shaking his head side to side and that long beard was swaying back and forth. When I asked him what was on his mind he simply said, I've been shoeing for nearly 50 years and in my opinion there is no way that those hooves are going to match or be balanced. I presented him with a challenge. I said, when those guys are done, you go and measure and check the work over. If you come to me following your inspection and if you feel that any of the hooves are more than an 1/8th of an inch out of balance to one another, I'll pack and leave before sitting down for lunch. 

Once the farriers were done, I moved to lecturing on functional anatomy with the rest of the group. Over my shoulder I saw this guy down on his hands and knees with a small tape measure. He measured medial and lateral hoof walls, he picked up each foot and eyed down the limb, and he check the HPA. 

In a few minutes I saw him standing at the back of the group and that beard was swaying back and forth again as he shook his head. I figured I was heading to Micky D's for lunch, but when I asked him for his conclusions he offered, "No more than a 1/16th of an inch, lets eat." 

There are many methods of trimming that subscribe to balancing the hoof to the foot's axis or COR. Whether you subscribe to theories presented by Mike Salvoldi, Gene Ovnicek, Dave Duckett, or the ever growing population of hoof experts, balancing around the axis of the foot is central to their work. Though all of these methods have merit, they each present a challenge. How do we balance the hoof to foot without a plane of reference? The Dynamic Balance Hoof Level is the first tool to offer a reliable plane of reference, that when followed results in repeatable balance. 

Below are photographs of a horse with toe-in conformation that was trimmed at the December Advanced Level Two Applied Equine Podiatry course in Ocala, Florida.  

The Advanced Level Course was also host to the first Dynamic Balance Hoof Level Certification Clinic offered by the Institute of Applied Equine Podiatry. The Dynamic Balance Hoof Level presents a reliable plane of reference around the axis of the foot, thus allowing the trimmer to establish balance in all horses, even those with less than ideal conformation. I will be presenting more on the DBHL in future posts, along with an instructional video. The Level will be available for purchase by the end of this month. 

before and after LF

before and after RF

HPA