Mis-matched Feet... The Controversy Continues...
Stephen E. O’Grady, DVM
I am continually asked to comment on mis-matched feet which farriers also refer to as the high / low hoof syndrome. Over the years as both a veterinarian and a farrier, I have recognized this mis-matched foot conformation but never considered it a problem. The farriery used was always based on principles to address the structures and function of each individual foot. In recent years with different breeding practices, training methodology, foot surfaces and various thoughts on farriery, a correlation between this type of foot conformation and lameness / stride abnormalities has emerged. Please see .
Mis-matched feet has been compared to laterality and limb length discrepancy (disparity) in the human literature but to my knowledge, this has not been proven to exist in the horse. Furthermore, it might be unrealistic to extrapolate from the human to the horse remembering that we are dealing with a biped vs. a quadruped. The etiology of this foot condition in horses must remain speculative at best. The only known study is from Europe where the authors looked at the grazing stance of a group of Warmblood foals where 50% of the animals developed uneven feet (vanHeel et al 2006). However, genetics and the developmental growth phase of the foal in the first year of life would appear to be possible contributing factors. This is the time frame where further study on the origin of asymmetrical feet could be relevant. If one considers genetics, mis- matched feet are often noted in foals as early as 10 days post-partum and some foals either fail to develop good palmar foot structures in one or both feet or they may develop a upright / clubfoot in the developmental phase of growth. Then, if the mare or grand dam is examined, very often, the same foot conformation observed in the foal will be noted in the mare on the same side. During the developmental growth period, foals kept under similar conditions and receiving the same routine farriery, some foals will develop an upright or club foot. As in the vanHeel study, it appears that a foal must have a propensity to develop a different unilateral foot conformation; however, an explanation for this observation remains elusive. Another area to consider is the length, tension and or laxity in the soft tissue structures in the distal limb of foals which may influence the growth and development of the immature foot. How many young horses reach their adult lives without having foot issues addressed as a foal or develop a clubfoot when they begin training?! Many questions but very few answers.
Mis-matched feet could be further divided into horses with a low heel foot and an upright foot or a low heel and a clubfoot. Here, the farriery principles for an upright foot would be different than a clubfoot (Figure 1). The concern with mis- matched feet is the correlation of either the long toe low heel conformation or the clubfoot conformation to lameness. Furthermore, either type of abnormal foot conformation can change stride length, however, a shortened stride length is generally appreciated more in the upright foot. It has been stated that mis-matched feet affect the saddle fit, a change in position of the scapula, increased tension in the shoulder along with effects on the neck and spine. However, these statements are based on opinion without any scientific proof or studies to confirm the theories. The fore limbs of the horse are suspended between the scapulae, lending some flexibility during weight bearing which has the potential to mitigate some of the ascending forces sustained during landing. This is opposed to hind foot conformation which has more effect on the upper body due to the direct attachment to the axial skeleton...weight bearing vs. propulsion. The high heel foot has been shown to have minimal effect on joint angulation above the fetlock (Turner et al 1987) and the DDFT appears to compensate for the low heel; therefore, any influence on anatomical compensation or performance may be related to a low grade lameness or gait asymmetry.
My practice does a lot of second opinions on forefeet radiographs from prepurchase exams. I submit a report looking at the images as both a veterinarian and a farrier. I never condemn the horse, but I describe any disease present along with abnormal foot conformation and the farriery aspects necessary to maintain and or improve the feet. Below are radiographs taken at a recent prepurchase examination (Figure 2). The horse was observed to be sound on the clinical examination. The radiographs shoe mis- matched forefeet and the RF foot has a severe low heel hoof capsule distortion with compromised soft tissue structures in the palmar foot. Obviously, in a young horse, severe mis-matched forefeet are a concern to the clinician as how to advise the purchaser regarding longevity, future soundness, and the potential for lameness. The example below shows the areas of concern highlighted on the images for the client to understand and as a template for the farrier to use as a guide for future trimming and shoeing (Figure 3).
Any proposed farriery I recommend is always based on using farriery principles rather than a given methodology and stressing the importance that each foot is addressed on an individual basis. Trying to match this type of foot conformation (which still occurs) is unrealistic and potentially harmful to the horse.