Morphology of the laminar junction in relation to the shape of the hoof capsule and distal phalanx in adult horses (Equus caballus).

The research aimed to find any potential correlation between the shapes of horse hooves and the anatomy of their ‘laminar junction’, a critical part of horse foot structure. It was discovered that differences in hoof shape but not in bone structure, correlate with changes in the morphology of the laminar junction. A decline in foot structural coherence was also noted in a sub-group of horses with distinct hoof angles.

Research Methodology

• For this investigation, ten fore feet from adult horses were used for analysis.
• The hooves were divided into normal and low-angle groups, based on the dorsal angle of the hoof wall.
• Twenty external hoof shape measurements and four measurements of the contained distal phalanx were compared between the two groups. Additionally, these measurements were tested for intragroup correlations.
• The morphology of the laminar junction was determined based on three factors—spacing, orientation, and degree of bending. Data was collected from up to 50 primary epidermal laminae at each of 20 sample sites. These sites were spread over the foot in five circumferential columns and four proximodistal rows.
• Differences in laminar variables between the two groups were analysed and correlated with the shape measurements.

Research Findings

• Results show differences in hoof shape between groups where the low-angle group exhibited a different morphology of the laminar junction. However, there was no difference in the shape of the bone.
• Six measurements: dorsal angle, medial and lateral angles, lateral sole width, solar circumference, and dorsal length, were significantly different between the two groups.
• In the normal group, hoof and bone measurements showed patterns of correlation between different regions of the hoof. However, in the low-angle group, these correlations were mostly seen within one region of the hoof (the heels) and in the bone measurements.
• Laminar spacing was non-significantly larger in the low-angle group, while variations for laminar spacing and orientation were significantly greater in this group.
• Laminar spacing correlated with bone width and coronary circumference (CC) of the hoof in the normal group, while it only correlated with CC in the low-angle group.
• Analysis of the results suggests a decrease in structural coherence of the foot in the low-angle group, indicating possible issues related to foot health and functionality.