Hoof and Foot development

In a previous blog post, ‘X Rays, Beyond Balance’, KC La Pierre introduced the exercise of Physiological Sequencing. Understanding how Physiological Sequencing applies to the structures of the equine foot can help us to be more pro-active in our efforts to prevent problems from developing.

To recap; Physiological Sequencing explains the order in which physiological processes occur.

Tissues are grouped into three types, according to the rate they respond to change: Soft Tissue, Dynamic Tissue, and Static Tissue.

Soft Tissue is vascular, meaning it contains blood and nerves. Any change of stimulus to Soft Tissue will immediately change the way the horse holds himself and moves in response. Soft Tissue changes cause the horse to move either more symmetrically or more asymmetrically. Such changes affect the foot almost immediately, as a change to how the horse moves will result in a change to how the stimulus is delivered to the soft tissue of the foot and therefore to the second tissue in the sequence, Dynamic Tissue.

The main Dynamic Tissues of the foot are ungular cartilage and hoof horn: They are avascular structures (have no blood supply or nerves). Ungular Cartilage forms the foundation of the palmar (rear) two-thirds of the foot, meaning that the confirmation of the cartilage determines the confirmation of most of the hoof capsule. The ungular cartilage and coronary band work together to suspend the internal foot within the hoof capsule. A soft vascular network of blood vessels, or ‘dermis’, sits between the internal foot and the hoof capsule. The dermis has many important functions in the foot, one of which is nourishing the horn of the hoof capsule. Confirmation and health of both the hoof capsule and the underlying cartilage, along with the application of stimulus determines how effectively the dermis is able to supply the horn with nutrients.

The dynamic hoof capsule is the vehicle for delivery of the stimulus to the foot within. The confirmation of the hoof capsule and health of the horn affects both how the dermis is stimulated and how pressure is delivered to the cartilage and coronary band throughout the stride of the horse. Ungular cartilage cannot be nourished by the dermis, it requires appropriate pressure in order to develop healthily. If at any point the horse feels pain in his soft tissues, he will alter the loading of the foot to avoid the pain. This may be very subtle and if left undetected, the result will be an improper development of the ungular cartilages and improper horn growth.  Physiological sequencing tells us that these changes will eventually affect the static tissue, the bones of the foot. 

Static tissue, bone, we understand is always in a constant state of flux, modeling, and remodeling, however, these changes can take longer for physical change to be seen. The changes are less immediately obvious than the other tissues in the foot. The pedal bone, P3, is unable to remodel due to it lacking a medullary cavity so modeling of this foundation bone of the foot is irreversible. Wolff’s Law states that cells will align themselves directly with the line of force. Using a radiograph the line of force can be seen in the density of bone cells where modeling has taken place, for instance in cases where the foot has been chronically imbalanced. Examination of the dynamic structures of the foot, together with the application of Physiological Sequencing, will point to why the Static tissue changes have occurred and how the dynamic tissues can be addressed in order to prevent further changes to bone.

All tissues of the foot are in a constant state of flux. Observing change and understanding what is correct structure and function allows us to ensure tissues are developing healthily. In his article ‘Did I do that?’, KC La Pierre describes how he identified a rider imbalance by noticing a lateral flare in one hind foot of each of her dressage horses. A rehabilitation program was put into place for the horses and the rider. This prevented the cause of the change to the Dynamic tissue of the horses from becoming the cause of bone change.

ETB Pegasus Gait Analysis technology accurately pinpoints where and when any asymmetry or irregularity of gait occurs. Soft tissue needs to be free of pain in order for the horse to move and develop as symmetrically as possible.

Early identification and treatment of pain and close observation of dynamic tissue whilst being mindful of Physiological Sequencing can increase our chances of preventing pathologies.

About the author: Penny Thorpe, DAEP came across Applied Equine Podiatry whilst working for two trainers who were clients of Trevor Jones DAEP. Curiosity to know a 'bit more about feet' led to a fascinating journey of study with the Institute, graduating as a DAEP in 2013 and starting second level study in 2014. She lives in Brighton with her family and is privileged to have a small practice of dedicated owners and lovely horses.

Re-writing the book on Chronic Laminitis

   
It has been some time since I last posted to this blog and I apologize to my followers. I have been busy promoting my new book "Laminitis, Founder, and Equine Digital Osteoarthritis".
The research required for the book has taken me to distant shores and far away places in the virtual world of academia. The title of this blog post is Re-writing the book on Chronic Laminitis and that is precisely what this new book does. I have presented glimpses of my work during lectures I presented at the University of Paris. In that talk I called for a change in perspective and a shift in paradigm. I suggested that research into the causes of chronic laminitis may be flawed because of the model that researchers subscribe to. The model that I am referring to is that of suspension. For decades research has been done following the premise that the lamellae attachment and subsequent loss of suspension of the distal phalanx was due to this tissue's degradation and that this loss defined the disease.
      Entertaining a new model for the suspension of the distal phalanx is.... A real game changer!
Over the past fifteen years we have proposed that the lamellae in and by themselves are not capable of suspension, this due to the fact that they have little to no elastic potential. It was back in 2002 that we conducted a study to define a hoof model that we have since used for research and teaching at the Institute, ultimately allowing us to literally re-write the book on chronic laminitis.
Adopting a new model for suspension has allowed us to develop studies that have provided evidence to support exploration of new treatments, both pharmacological and practical.
Our latest study, a histological comparison study has opened up new possibilities and shows great promise in helping to change the focus of current research.

This revolutionary book may be purchased by following this link: https://appliedequinepodiatry.org/product/laminitis-founder-equine-digital-osteoarthritis-diagnosis-and-treatment/

USDA on Soring

The USDA has released their decision regarding the proposed changes to the Horse Protection Act. The language in the Act has been changed to apply to Tennessee Walking Horses and Racking Horses. Spotted Saddle Horses "and related breeds" have been removed from the proposed regulation.)

USDA Announces Changes Aimed at Ending the Inhumane Practice of Horse Soring

January 13, 2017--WASHINGTON-- The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) today announced a final rule that includes changes that will help to protect horses from the cruel and inhumane practice known as soring and eliminate the unfair competitive advantage that sore horses have over horses that are not sore. The practice of soring is intended to produce a high stepping gait through the use of action devices, caustic chemicals, and other practices that cause horses to suffer, or reasonably be expected to suffer physical pain, distress, inflammation, or lameness while walking or moving.

APHIS enforces the Horse Protection Act (HPA), a Federal law that makes it unlawful for any person to show, exhibit, sell, or transport sore horses, or to use any equipment, device, paraphernalia, or substance prohibited by USDA to prevent the soring of horse in such events. APHIS works actively with the horse industry to eliminate such inhumane practices and the resulting unfair competition they create at HPA-covered events.

The final rule addresses recommendations made by the USDA’s Office of Inspector General following an audit of APHIS’ horse protection program, which found the existing industry-led inspection program to be inadequate for ensuring compliance with the HPA. The rule also seeks to address the substantial noncompliance that continues to exist among Tennessee Walking Horses and racking horses and the relationship that continues to exist between the use of certain prohibited items and soring in horses, such as the use of permitted action devices alone or in conjunction with prohibited substances.

Under the final regulation—

• APHIS will license, train, and oversee independent, third party inspectors, known as Horse Protection Inspectors (HPIs), and establish the licensing eligibility requirements to reduce conflicts of interest.

• To allow sufficient time to train and license HPIs and ensure an adequate number before the start of the 2018 show season, current Designated Qualified Person (DQP) licenses will remain valid until January 1, 2018. Beginning January 1, 2018, management of horse shows, exhibitions, sales, and auctions that elect to use inspection services, must appoint and retain a HPI to inspect horses.

• Beginning January 1, 2018, the regulatory provisions applicable to Horse Industry Organization and Associations are removed and are no longer effective.

• Beginning 30 days after the publication of the final rule, all action devices, except for certain boots, are prohibited on any Tennessee Walking Horse or racking horse at any horse show, exhibition, sale, or auction. All pads and wedges are prohibited on any Tennessee Walking Horse or racking horse at any horse show, exhibition, sale, or auction on or after January 1, 2018, unless such horse has been prescribed and is receiving therapeutic, veterinary treatment using pads or wedges. This delayed implementation allows ample time to both gradually reduce the size of pads to minimize any potential physiological stress to the horses and prepare horses to compete in other classes.

• Beginning January 1, 2018, management of HPA-covered events must, among other things, submit certain information records to APHIS, provide HPIs with access, space, and facilities to conduct inspections, and have a farrier physically present to assist HPIs at horse shows, exhibitions, sales, and auctions that allow Tennessee Walking Horses or racking horses to participate in therapeutic pads and wedges if more than 150 horses are entered, and have a farrier on call if 150 or fewer horses are entered.

Congress passed the HPA to end the cruel and inhumane practice of soring horses and stop unfair competition. Strengthening the HPA regulations and the enforcement of alleged violations is the best way to achieve this goal. In addition, the prohibitions on the use of action devices and pads (with certain exceptions) are consistent with recommendations made by the American Veterinary Medical Association, the American Association of Equine Practitioners, and leading industry standards for equestrian sports.

This final rule will be published in the Federal Register in the coming days.

The changes regarding the prohibitions on the use of action devices and associated lubricants for exhibitors of Tennessee Walking horses and racking horses, along with the training and licensing of inspectors will be effective 30 days after publication in the Federal Register. The rest of the rule will be effective January 1, 2018.

Flat foot? Concavity and Health

Concavity, Conformation or Health?

By KC La Pierre

We often receive emails from horse owners exhibiting frustration over their inability to aid their horse in achieving concavity to their horses' hooves. Usually it is said that their horse is footie (tender over rough or hard ground) after months or even years of being barefoot. They go on to explain that they are frustrated, because they feel that they have been doing all the right things; created a natural environment, provided exercise, have addressed nutrition and done all of the other things that are said to achieve concavity and health to the hoof. Why then is my horse still footie over rough ground and why can't I get concavity!

The first objective when attempting to answer such an email is to determine the true conformation and the state of health of their horses' foot. Lack of concavity is not something that can be corrected by trimming, and a lack of concavity is not always the cause for a horse being footie (stay with me here). Concavity defines conformation and not health. Taking a simplistic view of the sole does not serve the horse. The sole, like the hoof wall cannot be viewed or treated as homogeneous (having the same make-up throughout). The sole is divided into two distinct structures, the Primary Sole and the Terminal Sole. Each is defined by its conformation and the property of its horn (tissue). The Primary Sole is the horn that has a foundation of bone (that part of the sole that covers the coffin bone). The Terminal Sole is that which has a foundation of cartilage and forms around the perimeter of the coffin bone. Being familiar with the "Hoof Wall Matrix" will help you to determine the current state of health of both the primary and terminal sole. As the health of the sole increases a matrix is formed creating a healthy transition from terminal sole to primary sole. This matrix is important to overall performance.

Terminal sole consist of horn that is made up of terminal tubules (tough horn that distorts without failure) and intertubular horn, terminal sole allows for needed distortion. Primary sole consist of primary tubules (hard horn that provides stability, resisting distortion) and intertubular horn. The function of each is determined by its foundation. The chief function of the primary sole is to protect the coffin bone (its foundation), not from concussion, but rather from torque (twist). The primary function of the terminal sole is to allow for distortion (also protecting the coffin bone from torque), and to provide protection from blunt trauma. In both instances the horn needs to be healthy, have depth, and have a strong matrix.

Lack of concavity to the primary sole in truth defines the conformation of its foundation, the coffin bone. It is not possible to increase this concavity. If there is little concavity to the distal dorsal (bottom) surface of the coffin bone, there will be little concavity to the primary sole. The Unified Sole Theory by Mike Salvoldi describes uniform thickness of the sole. However, concavity of the hoof capsule is not defined by the concavity of the primary sole. Concavity of the solar (bottom) aspect of the hoof does increase with an increase in the depth of horn of both the primary and terminal sole. Why? Take a look at the illustrations presented here. 

You will see that as the diameter and height of a concave structure increases the depth of the concavity increases (its center is further from its perimeter). The concavity (conformation) of the primary (center) sole does not change, but the conformation of the overall solar aspect does. The internal foot is in effect further away from the ground surface and better protected by healthier thicker horn.

Many of the hooves presented with lack of concavity are in fact exhibiting a lack of depth in solar horn and poor matrix to both the sole and hoof wall.

Is lack of concavity to the primary sole a cause for concern? Because function is determined by conformation and the property of a structure's tissue, a lack of concavity to the coffin bone can result in a diminished ability to dissipate the energies created during the stance (load) phase of the stride. Some horses can handle higher levels of energy and cope well with a flat conformation (within limits), where others are more sensitive to the energies resulting from a flat conformation. If your expectation is for high performance where the foot is exposed to high levels of energy, then conformation of this sort does become a concern.

How can we help the horse with such conformation? After all concavity cannot be returned to the coffin bone. As I mentioned earlier in this article depth of sole can be increased, that is if the conditions are right. Following two principles of Applied EquinePodiatry can help in developing a treatment protocol that can help in the development of a stronger hoof capsule (including Sole).

1.       Accepting that the horse does have the natural ability to heal itself, this provided the environment is conducive to healing.

2.       That correct force is the stimulus for correct growth

When examining environment you must take into consideration not only terrain, but also nutrition, exercise, and how the hoof is treated (balanced, trimmed/shod). 

Starting with a balanced hoof and exercising within the defined Spectrum of Usability for the horse are paramount to success. 

If you are dealing with less than ideal conformation of the coffin bone do your homework on foot function.

It is not possible to increase the concavity of the foundation, but it may be possible to increase the health of those structures that will supplement foot function.