The Influence of Body Mass and Height on Equine Hoof Conformation and Symmetry

Despite the likelihood that a horse's mass influences hoof morphology, empirical evidence is lacking. A clearer understanding of factors influencing hoof shape could enable prevention, or better treatment, of foot-based disorders; common causes of equine lameness. The study's aim was to investigate the relationship between horse body size, in terms of mass and height, and fore hoof dimensions. A further aim was to determine changes in the occurrence of hoof asymmetry as body size increases. Height, mass, and fore hoof dimensions; coronet band width (CBW); hoof base width (HBW); dorsal hoof wall angle (DHWA); and hoof spread (HS) of 63 riding school horses were measured within two weeks of routine shoeing. Regression analysis demonstrated positive relationships between body mass and both CBW and HBW in left and right hooves, indicating basic hoof dimensions increased as body mass increased. No relationship between horse height and hoof variables was found, suggesting mass is more influential on hoof morphology. Left and right DHWL were moderately correlated; however, paired t-test results identified a greater right than left DHWA. As left DHWA increased, left HS decreased, indicating development of a more upright hoof geometry. Both left and right HS increased as corresponding HBW increased. Both hooves tended toward a more upright conformation as horse height and body mass increased. However, asymmetries observed suggest a splayed left hoof compared to a "boxy" right hoof. Such morphological adjustments may indicate variation in horn tubule orientation in response to greater structural loading; an important consideration for hoof practitioners.