Sole depth and weight-bearing characteristics of the palmar surface of the feet of feral horses and domestic Thoroughbreds.

This research studied the sole depth and weight-bearing characteristics of wild and domestic horses’ feet, finding differences that suggest wild horses’ hooves have a load-bearing function and are less flexible than domestic horses’ due to their robust architecture.

Study Purpose and Methodology

• The research aimed to determine the load-bearing structures found in the soles of wild horses, and to identify morphological distinctions between the paw pads of wild and domestic Thoroughbred horses.
• For this purpose, researchers used forelimbs from cadavers of 70 wild horses and 20 domestic Thoroughbreds in Australia.
• The left forefeet were selected from three wild horse populations found in soft substrate (SS), hard substrate (HS), and a mixture of the two. These feet were loaded in a lab setting to simulate the forces they would experience in real life.
• The distribution of pressure on the feet was measured using a pressure plate, while the depth of the sole was measured at 12 different points across the solar plane.

Key Findings

• Findings indicated that the feet of wild horses from hard substrate environments loaded the periphery of the sole and the hoof wall on a flat surface, suggesting a load-bearing role of the peripheral aspect of the foot.
• The research established that wild horses from both hard and soft substrates tended to have a greater mean sole depth than domestic Thoroughbreds.
• The depth of the horse’s sole was greatest at the periphery, and this depth was correlated with the loading pattern. This implies that where the depth was pronounced, the pressure exerted was also more substantial.

Conclusions and Implications

• The study concluded that the peripheral part of the sole in wild horses carries a load-bearing function. These findings suggest that the hoof capsule of wild horses might be less flexible than that of typical domestic horses due to the robust nature of the tissue structure.
• Furthermore, the findings raised questions on the application of narrow-web horseshoes often used for domestic horses, suggesting they may not maximize the load-bearing and force-dissipating properties of the hoof’s peripheral aspect.
• The study proposed further studies should be conducted to understand how biomechanical stimulation affects the feet of horses and how their hooves adapt to these stimuli.