The influence of trimming of the hoof wall on the damage of laminar tissue after loading: An in vitro study.

This research article examines the effect of thinning the hoof wall on the damage to the laminar tissue in horses’ hooves. The study found that reducing the thickness of the hoof wall can decrease the disruption of laminar tissue, suggesting that this could be a preventative measure for horses at risk of hoof failure.

Research Motivation and Outcome

• The primary motivation for this study was to investigate whether thinning (trimming) the hoof wall, which leads to increased flexibility, has an impact on the damage to the laminar tissue created by loading the hoof.
• The specific structure in focus here is called suspensory apparatus of the distal phalanx (SADP), a tissue structure that connects the innermost bone in the horse’s hoof (the distal phalanx) to the hoof wall.
• The researchers found that hooves with a thinned hoof wall underwent significantly more deformation, which is to say they were more flexible. However, they showed less laminar tissue disruption, which contradicts what might be expected.

Research Method

• The experimental setup used paired cadaver forelimbs from twelve horses. In each pair, one hoof wall was thinned by 25% – verified using radiography – while the partner hoof was left as it was and used as a control.
• The hooves were then loaded with a force in a specific direction at a steady rate using a mechanical testing machine. This continued until a specified limit – either in force (8kN) or extension (14mm) – was reached.
• Once the testing was completed, samples of the SADP were taken for examination under the microscope (histology).
• The level of damage to the SADP was evaluated in two ways. Firstly, by digitizing the image and analyzing the resulting histogram, which gives a quantitative measure, and secondly, by a panel of three reviewers who weren’t aware of the treatment each hoof had received, which provides a qualitative judgement.

Significance of the Findings

• The findings have the potential to be quite significant in equine health, as they suggest that trimming or thinning the hoof wall can be a preventive measure to protect against SADP failure, which is associated with a painful and debilitating condition called laminitis.
• However, the authors stress that these results are based on an in vitro study, which is experimental and carried out in controlled lab conditions. Additional research, particularly in vivo testing (i.e., on live animals), is necessary to verify these results before they can be considered reliable for actual prevention strategies for laminitis in horses.