A permeability barrier in the dorsal wall of the equine hoof capsule.

The research investigates the permeability barrier in the dorsal wall of the equine hoof capsule, identifying that the quality of the horn from horse feet significantly impacts its permeability, particularly in instances of poor quality horn which had a weaker barrier.

Research Methodology

• The research conducted an experiment using horseradish peroxidase (HRP) in a saline solution as a water-soluble tracer and 3’3′-diaminobenzidine tetrachloride (DAB) treatment to examine the permeability barrier in the dorsal wall of equine hoof capsules.
• Horn quality from 10 different horses was assessed and subjectively graded as either good or poor. Samples were collected from various regions of the hoof, including the outer surface, outermost layers of the horn, cut edge of the outer layer, inner layer of horn, cut edge of the inner layer and laminae.
• These tissue samples were left in either an oven at 60 degrees Celsius or soaked in water for two weeks before treated in HRP, sectioned and treated with DAB solution.

Key Findings

• The researchers observed that ‘normal’ horn, deemed of good quality, showed minor penetration of HRP, suggesting a strong permeability barrier.
• The inner wall layers of ‘normal’ good-quality horn allowed tracer penetration up to 20 cell layers deep, indicating a porous nature within the cells and intercellular spaces.
• On the contrary, horn sections from horses with brittle feet exhibited deep cracks in the outer layer, leading to major penetration of HRP, which indicates a less effective permeability barrier.
• Soaking good quality horn in water for two weeks did not impact the permeability barrier. However, soaking brittle horn under the same conditions resulted in an increased permeability to HRP.
• Heating the horn in an oven did not impact its permeability barrier, thereby ruling out heat as a significant factor in altering the permeability.
• The study concluded that the permeability barrier effectiveness varied based on the layer of the dorsal wall, and better-quality horn had a stronger permeability barrier as compared to horn of poorer quality.