Quantitative Analysis and Development of the Fore Feet of Arabian Foals from Birth to 1 Year of Age

Objectives The goal of this study was to quantify external and internal anatomical characteristics of the foal foot throughout the first year of age. Methods Digital radiographs and photographs were taken bimonthly of the forefeet of nine Arabian foals, beginning at about 2 weeks of age until 12 months of age. Sixty-eight linear and angular variables were measured using NIH (National Institutes of Health) Image J software. Statistical analyses were performed using piecewise random coefficient model and p -values<0.05 were considered significant. Results Distinct changes in hoof development were identified between 4 and 8 months of age. Distinct changes were identified in several external (conformational) measurements including hoof solar widths and lengths, palmar heel lengths, toe and heel angles and in several internal (radiographic) measurements including the widths and lengths of the phalanges and sesamoid bones as well as joint angles. Clinical Significance Existing knowledge of distal limb development in foals, particularly the foot, is limited. These findings define the measurable changes of the foal foot as it grows during the first year of life. These data provide an insight into the transformation of the hoof from its initial oval to a circular shape and from a club-like, cylindrical conformation to a more angled, conical conformation. This paper quantifies this development, ultimately allowing a better understanding of morphological changes in the foot of the growing foal.