07/14/2025
Man Made Foot Problems in the Horse
Brian S. Burks, DVM
Diplomate, ABVP
Board-Certified in Equine Practice
The ideal foot is to support the weight of the horse on the hoof wall. The hoof wall is thicker at the toe because it undergoes more wear and tear as it breaks over than other portions of the hoof. The hoof wall is attached to the third phalanx by the epidermal and dermal laminae, along with the suspensory apparatus of the distal phalanx.
This SADP is made of collagen fibers that attach to ridges on the distal phalanx (coffin bone) and the epidermal laminae. This makes a continuous attachment from the outer hoof wall to the pedal bone. When the horse lands on the foot, it has a force of nearly twice its weight and 67% of the shock is taken and dissipated by the SADP.
The normal forces acting on the foot demand the structure to be sound and sturdy. There is tension directed to the laminae, tension from the deep digital flexor tendon, downward compression from the middle phalanx (short pastern bone), upper compression from the sole, and forces acting on the extensor process, including extensor branches of the suspensory ligament and the common (or long) digital extensor tendon. The normal forces exhibited on impact are quite complex. The heels strike first, followed by the ground surfaces of the bars, quarters, and toe. Most horses land very nearly flat.
The sole is slightly depressed as it opposes the downward force and the frog and sole support the internal hoof structures, helping to dissipate force upon the distal phalanx.
Wild horses do a good job of wearing their feet naturally as they roam over 100s of acres of land. They must roam to find water and good forage, so their feet are trimmed in the process. Horses in the wild must have sound feet to escape predators; those with unsound/lame feet will end up as a meal. This is called survival of the fittest.
The domestication of horses has changed how nature cared for horses, and now horses’ feet are trimmed and shod in a myriad of ways. Some breeds, notably American Saddlebreds and Tennessee Walking Horses, have their feet in abnormal conformation to perform different gaits. Unfortunately, the wall grows long, removing frog pressure and allowing heel contracture. This makes them subject to a myriad of disorders, including thrush, tendon injuries, ring bone, navicular disease, and contraction of the hoof around the distal phalanx (hoof bound).
Quarter horses are now often bred for small feet, but large bodies. There is not enough foot to provide proper foundation. The small foot cannot handle the load being put upon it, and lameness often results.
Thoroughbreds often have poor feet, as they have been selected for other traits, with conformation and the foot being sacrificed.
Hoof size in horses is highly heritable and correlates with bone growth. Hoof size is also influenced by nutrition. Horses that are fed an optimum diet have an 80% increase in hoof-sole-border size compared to those fed a limited diet. Good nutrition encourages maximum bone and hoof size, leading to soundness.
Maintaining healthy feet also includes hoof moisture. The hoof wall has a stiffness gradient, with the driest portion externally and the interior laminae having more moisture, which allows for flexibility. Horses that stand in a continuously wet environment have poor feet because they imbibe water from the environment. Drier feet are harder and tougher. Wet feet lose their strength due to deterioration of the hoof wall tubules and their matrix. The heels become compressed, the hoof becomes out of balance with the breakover moving forward- long toe, short heel syndrome or underrun heels.
Out-of-balance feet and underrun heels put tremendous pressure upon the navicular bone and the deep digital flexor tendon, along with other ligaments around the navicular bone and coffin joint. There is stress and tearing of laminae.
Moving the breakover point (usually about ¾ inch in front of the frog apex) disrupts the forces on the DDFT and navicular bursa. The forces are no longer distributed evenly. This leads to compression of the digital cushion and heel compression from abnormal loading, further reducing heel growth and forcing the toe forward. Many problems in the foot have to do with trimming and daily care.
Removing too much from the hoof, leaving little support and over-trimming the frog are contrary to having a good foot. The frog should be in contact with the ground and should have a broad base at the heel. Small, narrow frogs with a crevice in the heels or the central frog sulcus do not help pump blood out of the foot and the hoof will grow less and become less sturdy.
1. Make sure your horse’s hooves are long enough. There are many important and sensitive structures inside the hoof that need to be protected; that protection is the hoof. Your horse must have a certain amount of hoof in order to keep the tendons, ligaments, bones, and other soft tissues from becoming bruised and battered.
Horse Weight Toe length
Horse Size Kg Pounds Cm Inches
Small 360 – 400 800 – 900 7.6 3.0
Medium 425 – 475 950 – 1050 8.25 3.25
Large 525 – 575 1150 – 1250 8.9 3.5
2. Be sure that there is adequate sole depth. The sole protects sensitive internal structures, so avoid carving out swaths of sole; removal with a stiff brush may be sufficient in some cases.
3. Trim to an angle appropriate for your horse. There is no ‘proper’ angle. Every horse is different. Most horses should have a straight hoof-pastern axis.
4. Use a large enough shoe. The foot should not be made to fit the shoe; rather the shoe should be made to fit the foot. Small shoes lead to contracted and underrun heels. This leads to degeneration of the navicular bone and its associated structures by causing inflammation. Use the biggest shoe the horse can practically wear.
Maintaining good feet takes effort. Proper trimming and shoeing, good nutrition, moisture balance, etc. help make good feet. Man-made problems can be overcome with diligence. Remember: “No frog, no foot, no foot, no horse”!
Fox Run Equine Center
www.foxrunequine.com
(724) 727-3481
