What constitutes a correct barefoot trim? This is the most frequently asked question I hear from clients. This question is like a lightning rod for me. I am passionate about horses having good, sound, functional feet. I am also pro-natural, and prefer a horse to be barefoot.
It was once believed that hoof balance should be based on degree measurement, or hoof angles. Hoof balance includes many aspects of a horse’s conformation and movement, and research has brought to light new ideas and concepts about it. The most popular one today is the Dorsal-Palmar balance system. This method relies on using an imaginary continuous line which runs down the center of each pastern and hoof, from the top of the pastern to the ground. If this line is continuous and unbroken, it is considered to be an “ideal” angle. Traditionally, the hoof angle referred to the angle created by the front (Dorsal surface) of the hoof and the ground (Palmar surface). Desirable angles were between 45º to 50º for the fronts and 50º to 55º for the hinds.
Thanks to intensive study on feral mustangs and the current barefoot movement, it’s becoming generally agreed that in reality these angles are far too low. A more representative range of hoof angles is 53º to 58º for the fronts and 55º to 60º for the hinds.
The hoof angle is considered correct when the hoof and pastern are in alignment. That is, when the front surface of the hoof is parallel to an imaginary line passing through the center of the pastern.
Three areas of balance
Hoof balance can be broken down into geometric, dynamic and natural balance. These three areas may be mutually exclusive, and it may not be possible to satisfy all of them simultaneously.
1 Geometric balance measures the horse’s foot while at rest. It observes that the foot is trimmed so the ground surface of the hoof is perpendicular to the long axis of the limb. This does not take into consideration the stacking of the bones and joints, and how the landing pattern of the foot affects the physiological relationship between the conformation of the foot and the leg it is attached to.
2 Dynamic balance implies that a balanced foot should land symmetrically, so the force of the landing is spread uniformly across the solar surface of the hoof wall. Almost no horses can be trimmed to land flat without risk of injury.
Breakover is the phase of stride between the time the horse’s heel lifts off the ground, and the time the toe lifts off the ground. Everyone talks about breakover but almost no one considers the effects of altering it. The toe is like a fulcrum, and just before break over the suspensory ligament to the navicular bone and the impar ligament are under maximal stress. If you randomly alter toe length, hoof/pastern axis, or hoof angle, this alters the tensile forces on the deep digital flexor tendon. A shorter toe, such as is seen on feral horses, is generally preferred over the longer toe that “traditional” trimming recommends.
Research has also found that longer toes encourage lamina tearing, which in turn results in hoof distortion. A whole host of lameness issues arises from this. However, you cannot just go from long to short in one trim. When trimming, less is more! Slow gradual change over several trimmings allows the ligaments and tendons to adjust to this new balancing act without injury.
A traditional trim
In a typical pasture trim, the heels are left long. This encourages contraction and can lead to navicular pain. The toe callous is trimmed away, leaving the tip of the coffin bone unprotected. The walls are flat and left higher than the sole so they have to support the entire weight of the horse. Flares are often ignored, which puts strain on the laminar connection and results in poor suspension of the coffin bone. This makes the horse more susceptible to laminitis. Trimming is often carried out on an infrequent basis, so the hooves are often not in an optimum state.
The barefoot trim
When I administer a barefoot trim, I ask to see where he spends his leisure time. I have the owner walk him away from and towards me, to see how he moves. I then have a really good look at all four feet, watching for wear. I measure the hooves at their widest points and record these measurements in the horse’s file, as well as the last date they were trimmed, and the owner’s assessment of how much the horse has been worked since the last trim. On each hoof, I chalk on the solar surface and up the hoof horn to mark the breakover.
•I trim frog, sole and bars only where necessary to remove loose, exfoliating material. If I see that debris is packing into the clefts and under the edges of the frog, I will trim the frog just enough to facilitate cleaning and minimize the chances of thrush.
•Next, I lightly pare the sole along the sole wall junction (white line) to determine the amount of hoof wall to be removed. I try never to use hoof nippers; I instead prefer the fine control of the rasp. It might take longer, but the rasp is a much more forgiving and exacting tool.
•If I do use the nippers, I never cut the hoof wall at the heel. I rasp the heels according to the conformation of each foot. I never trim the heels below the ground surface of the frog.
•If I need to “back up” the toe, I back it off to no more than the thickness of the hoof wall.
•I take great care to leave the frog level with the ground surface of the wall at the heels.
•Many farriers remove a thin layer of sole at the sole-wall junction, saying this ensures there is no sole pressure. I do not pare away any of the sole. Nature will allow a healthy sole to develop its own concavity as it grows a protective callous. If we pare away what protective layer the horse has, we expose that tender under-tissue, leaving the horse touchy and open to stone bruising. I f we leave the sole on, it will slough off on its own when no longer required for protection.
What about the competition horse?
Barefoot horses are competing in every field of athletics, all over the world. If a horse is conformation-compromised and needs more time in transition before he can be worked barefoot, you can choose from a staggering array of hoof boots. And by providing a variety of footing in a horse’s environment, you give him the tools to build better feet.
What we do to the hoof through trimming and shoeing affects the internal foot structures and the leg. The horse should have a foot/shoe configuration that matches his size, conformation and limb motion, as well as his athletic endeavor. Sound physiological shoeing can only be achieved by thorough knowledge, and a strict adherence to and skillful application of that knowledge.
I consider hoof trimming to be an art form, and have found that I rarely “paint the same picture” twice. I let the whole horse tell me the story of the trim his feet need. Although I keep track of the angles and details, they are not as important to me as the freedom of a horse with happy feet. Horses are born barefoot, and if we care for them with compassion and understanding, they can enjoy sound, happy lives barefoot!
Carol Lewis lives and works in Central Saanich on Vancouver Island, British Columbia. She is an Equine Service Provider and artist as well as Host Mother to ESL students from all over the world. As a graduate of the University of Guelph Equine Science Certificate, and an active member of her local equine community, she encourages horse owners to become educated and informed about current research-based information on equine health care. Her business, Xqizit Horse Health Services, a division of Xqizit Art, educates and assists horse owners in ensuring their equine companions get the best care possible, based on scientific research and current information.