How hoof form affects your horse’s limb function and conformation.
Can foot form really affect a horse’s conformation? Rest assured it can and does – in fact, it affects much more than that! The condition, overall shape and functioning of your horse’s feet influence not only his posture, stance, attitude, personality and movement, but also his bodily functions such as circulation, lymph function, digestion and muscle development. We will even go so far to say that hoof form and function have a great influence on your horse’s trainability and soundness – physically, emotionally and mentally.
What is good hoof form?
A few simple guidelines can be used to assess whether your horse has healthy hoof form.
From the side, your horse’s hoof should look triangular. With the limb fully weighted, the hairline (or coronet band) should be straight and resting at a 30° angle. The front (dorsal) angle should be roughly 45° to 50° in the forelimbs and 50° to 55° in the hind limbs.
From the front, the coronet band should appear level and straight – any humps or deviations in shape indicate uneven pressure.
From the rear, your horse’s heel bulbs should be thick, round and low to the ground. You should be able to fit one or two fingers comfortably between the bulbs. From the bottom, the frogs should be thick, dense, triangular pads, blending smoothly with the heel bulbs to form a “heart” shape. The sole should be smooth and convex, forming a bowl. The bearing surface of the heel should be level with the widest point of the frog, and the hoof wall should be approximately the same thickness all the way around.
The white line should be a solid elastic “seal” all the way around. Any black material or gaps in the white line are not acceptable and your horse could present with lameness until this is rectify
Contraction refers to an excessively narrow foot, with heels and bulbs pinched together. This is one of the most common pathologies afflicting domestic horses today. Contracted feet can be linked to a host of behavioral problems such as bucking, rearing, teeth grinding, tripping, headshaking, rushing or balking. Jumping horses with contracted hooves will be “dirty stoppers” – refusing to jump fences with the shock-absorbing system in their feet compromised. These are often horses who will “bronc” or bolt away from the landing side after jumping.
Thrush always goes hand in hand with contraction. When the heel bulbs are pinched together, the frog is also stressed, pinched and crowded. It will atrophy and shrivel up which makes it susceptible to ever-present opportunistic bacteria and fungi. Many horse owners do not recognize thrush because it is so common. We are told to occasionally apply some caustic goo in blue, purple or green and forget about it. What is not realized is the impact unhealthy frog pads can have on limb function. When the frog pad is hurt, the horse will begin to avoid using them and land “toe first”. This landing limits the horse’s stride range by several inches, and the compromised use of the limb with each stride predisposes him to soft tissue injuries such as tendon or suspensory injuries. Long term, this type of movement leads to navicular or DDFT lameness. Thrush pain can also cause a horse to stand over at the knee; commonly considered a conformation fault, this flaw can often be “cured” with improved hoof management!
Under-run heels are also known as “under-slung” or “crushed” heels. This condition is often confused with a horse that “doesn’t grow heel” or has “no heel”. In fact, these horses generally have excess amounts of heel, but it is easily overlooked because it grows on a dramatically forward plane. These horses can be predisposed to bowed tendons and suspensory injuries.
Flares are one of the most preventable hoof pathologies, and a major contributor to winging/paddling gaits. Simply provide a balanced trim at regular intervals, and fl ares will become a non-issue in your horses. Some horses do need a shorter trimming/shaping schedule of just a few weeks to gain control and heal the fl are thoroughly. Do not leave your horse for months between trims.
Cracks and chipping are also very preventable. Balanced trimming at short intervals will “cure” chronic cracking problems. If your horse has quarter cracks, or chips in the quarters, he is receiving a “flat” or non-functioning trim. He is simply shedding excess material. Trimming to accommodate the natural plane of the foot will eliminate the problem. If your horse has a coronary band injury, he will probably grow out a thin crack like a scar. This should not affect his performance.
Medial/lateral imbalance refers to a horse whose hooves are imbalanced left to right. Shockingly, many horses are trimmed and/or shod out of balance for years at a time! These horses often have uneven arthritic changes in the joints of the lower limb (appearing as hard “bubbly” material surrounding the joints). This imbalance can be a major contributor to ringbone and sidebone. Improvements can be made to these conditions through regular, balanced trimming, resulting in increased comfort and longevity for your horse.
When a healthy and fully functioning equine foot strikes the ground, it will expand approximately 3mm to 5mm and fill with cushioning blood. As the foot leaves the ground, it contracts, expelling blood from the foot. The action of your horse’s feet assists his heart in pumping blood throughout the limbs and body, as if he has five hearts. Certain pathologies can disrupt this process, restricting blood fl ow and limiting the function of his feet. Now think – if four of your horse’s “hearts” are constricted, how is the fifth to function at full capacity? Imagine the potential of your horse if he were able to fully utilize all his resources.
As you can see, a properly formed and functioning foot affects your horse’s entire well being. Pay close attention to his hooves, and address any imbalances and pathologies with your trimmer as they arise, for optimal health and performance.
Lisa Huhn is the author of Make The Connection Triminology 101 Field Study Guide, and the founder of equinextion.com and the Eq Awakenings Study Center in Aberta. She calls herself a lifetime student of the horse.
Catherine Katsirdakis is a certified EQAT living north of Fergus, Ontario. She is currently keeping a client base for trimming and has a facility where she brings client horses in for rehabilitation. For more information read the textbook Triminology 101 by Lisa Huhn.