The Equine Education Hub

Course curriculum

The use of steel horseshoes is common practice in every equestrian discipline, from the most basic leisure horse to the highest level of performance horse. Recent studies have revealed that shoeing involves some potentially deleterious effects on horse soundness (Cook 2003, Clayton et al., 2011). There is a growing trend of barefoot horse keeping, with owners, researchers and scientists beginning to question the effects of permanently attaching the inflexible material of a steel shoe to a living, flexible structure of the keratinous hoof, and studies are beginning to identify effects on the physiology of the horse as a result, involving proprioception, limb kinematics, limb kinetics and energetics (Clayton et al., 2011, Panagiotopoulou et al., 2016; Ault et al., 2015; Benoit et al., 1993). Studies have mainly focused on the transferral of ground reaction forces changes and how these affect the structures within the equine limb - assessing bones, tendons and ligaments - yet little research appears to have been carried out to assess the direct effect on the hoof capsule (Panagiotopoulou et al., 2016). This study aimed to ascertain whether differences exist between the protein profiles of shod hooves compared to unshod hooves. Hoof samples were extracted from fourteen horses of varying breed, age, sex, workload and diet. Seven of the horses were shod with standard non-remedial steel horseshoes and seven were unshod. The unshod horses were trimmed by the same fully qualified Equine Podiatrist (a member of the Equine Podiatry Association), and the shod horses were shod by two different farriers, each fully qualified members of the Farriers Registration Council. Hoof samples were analysed for protein composition to ascertain whether any proteomic differences exist between shod hooves and unshod hooves. The shod hooves contained significantly more proteins in the molecular weight range for Keratin type proteins compared to the unshod hooves (P=0.000), this probably includes structural keratins as well as intermediate filaments. It is hypothesised that the application of the metal horseshoe alters the structural composition of the hoof keratin by a number of mechanisms, including increased mechanical stress, heat stress, increased ground reaction forces, increased vibrations, reduced shock absorption mechanisms and impaired circulation. Protein with a molecular weight consistent with Keratin 17 (K17) was identified in all of the shod hoof samples but was absent in almost all of the unshod sample. K17 is associated with injury response in keratinous tissues.