What Makes the Natural Trim Different

In my practice, a question that is often asked by new clients and those interested in natural hoof care

 is “what’s the difference between a natural trim and a farrier’s trim”?  The primary difference is that the majority of farriers trim a hoof as if they were going to then apply a shoe.  The natural trim is modeled after the healthy, self-trimming hoof of the mustang in the wild. 

When a hoof is prepared for shoeing, the excess wall length at the toe is removed with nippers and wall and toe callus are then rasped flat to give a uniform flat surface around the wall upon which to fit the shoe.  The walls from the quarters to the heels are left longer, well above the level of the sole.  Farrier texts instruct the farrier to take care not to trim the quarters even with the sole plane or there will be a low spot that will not meet the shoe.  The heels are left high so that the frog does not contact the ground. The sole is pared to create concavity and to raise the sole off the ground and prevent bruising.  The bars are trimmed level to the pared sole.  The frog is routinely trimmed to give it a neater appearance.  Flaring in the hooves is often ignored.  The outside edge of the hoof wall is left flat and unfinished.  Trimming is usually maintained at a six-week or longer interval. 

The natural trim (or physiological trim as termed by Dr. Robert Bowker, VMD, PhD, and director of the Equine Foot Laboratory at the College of Veterinary Medicine at Michigan State University) is a method of trimming that allows the tissues of the hoof to function optimally as a shock absorber.  Through his research Dr. Bowker has discovered that blood flow in the back part of the hoof is the major mechanism for absorbing concussion as the hoof impacts the ground.  He found that the foot hits the ground heel-first in virtually all wild horses and the majority of sound domestic horses. 

A physiologically correct hoof is a balanced hoof with a short toe, low heel, callused, naturally concave sole, and a wide, well- developed frog which makes contact with the ground.  When the back part of the hoof does not make contact with the ground, concussion is not properly absorbed but is transmitted to the bones and other tissues of the foot that are not designed to absorb such an impact, leading to chronic foot problems and lameness. 

In a natural trim the excess wall length at the toe is removed allowing for a 1/16^{th -inch} rim above the sole at the toe.  In an initial trim (if the hoof is very overgrown), the sole and hoof wall will be trimmed, but never past the live sole.  In future trims, it is usually not necessary to trim much sole (if any), if the horse is provided with an environment that encourages plenty of movement. The sole is never pared out to create concavity.  The goal is to allow the sole to develop an even thickness, which will then create a natural concavity that mirrors the underside of the coffin bone.  Trimming in this way preserves the sole at the front of the foot, reducing sensitivity and providing more depth of sole to protect the coffin bone.  According to Dr. Bowker, the sole is intended to be the primary loading surface at the bottom of the foot; concavity is not there to lift the sole off the ground.  The bars are trimmed so they are slightly passive to the hoof wall, but never removed.  Removing the bars hinders sole growth, weakens the back of the hoof and disturbs the integrity of the internal arch.  

The walls from the quarters to heels are trimmed continuing the 1/16^{th -inch} rim above the healthy sole, following the natural arch at the quarters.  By following the natural arch of the quarters, pressure points are reduced, promoting even wall growth that is resistant to flaring, chipping, and quarter cracks. The heels are trimmed by first gauging the sole depth at the back of the foot (to insure adequate sole coverage), and then trimmed to allow the back of the foot to have contact with the ground.  If the horse has not been previously trimmed in this way, and the heels are long, then the heels will be gradually lowered over the course of several trims.  This allows the hoof to gradually adapt to the change.  The frog is not overly trimmed – which allows the frog to toughen and callous, reducing sensitivity and acting as a natural barrier to thrush.  Flaps that may trap manure will be trimmed as well as any diseased material.

Any flaring is addressed by rasping the lower third of the hoof wall to achieve a uniform natural thickness.  Finally, the bottom of the hoof wall is finished with a bevel, or “mustang roll.”  By rolling the wall the hoof is not subject to a separation force which makes the wall prone to chipping and cracking and contributes to flaring, stretched laminae, and laminitis.  It also eases breakover.  Trimming intervals are shorter, between 4 – 6 weeks.  Extended intervals between trimming force the hoof and leg to adjust to the radically longer or shorter hoof.  Finally, a good natural trimmer will ask an owner to implement some natural horse keeping practices (as many as the owner is able to and is comfortable with) in order for the trim to be as successful as possible.

The goals of farriers and natural trimmers are different.  Most farriers trim a hoof to take a shoe; natural trimmers seek to mimic natural wear.  For more information on natural hoof care there a number of excellent websites, including www.hoofrehab.com, and www.thehorseshoof.com.