Equine hoof wall tubule density and morphology.

Density and morphologic features of hoof wall tubules in horses' hooves are described. The sample population consisted of hooves (n=12) from both live and deceased adult horses. Full wall thicknesses of the hoof wall were prepared histologically from sites at the toe, medial quarter and lateral quarter. In defined areas, tubules were counted, and density was calculated across the three histologically defined areas of the stratum externum, stratum medium and stratum internum along with the descriptive morphologic features of the tubules. Morphologically, distinct zones were demarcated by varying tubular cortical and medullary characteristics. Tubule density showed a radially increasing pattern across the wall thickness. Significant regional differences in density were found in the toe, lateral and medial walls. These findings represent a first study of regional differences of tubular densities. Hoof horn clippings from live feet may have potential diagnostic and/or prognostic value.