Epidermal tubules [Horn tubules]

The epidermal tubules, also called horn tubules, are microscopic, cylindrical columns of keratinized epidermal tissue that run proximodistally within the hoof wall, embedded in the intertubular horn.

They are produced by the dermal papillae of the coronary and laminar corium and play a major role in the mechanical strength, elasticity, and load distribution of the hoof wall.