Pododermal angioarchitecture in the equine hoof wall: A light and scanning electron microscopic study of the wall proper
Issue title: Selected post-conference papers of the 38th Conference of the German Society for Clinical Microcirculation and Hemorheology, 21-23 November 2019, Braunschweig, Germany
Guest editors: P. Wiggermann, A. Krüger-Genge and F. Jung
Affiliations: [a] Institue for Animal Hygiene, Animal Welfare and Farm Animal Behaviour, University of Veterinary Medicine Hannover, Hannover, Germany
| [b] Institute of Veterinary Anatomy, Faculty of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| [c] Dahlem Research School, Freie Universität Berlin, Berlin, Germany
Correspondence:
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Corresponding author: Dr. Henrieke Sievers, Institute for Animal Hygiene, Animal Welfare and Farm Animal Behaviour, University of Veterinary Medicine Hannover, Bischofsholer Damm 15, D-30173 Hannover, Germany. Tel.: +49 511 856 8957; E-mail: Henrieke.Sievers@tiho-hannover.de.
Abstract: BACKGROUND:Blood supply is an important factor for the normal function of the equine hoof, but earlier studies present conflicting data on functional characteristics of its angioarchitecture. OBJECTIVE:Emphasis was laid on demonstration of the microvascularisation in the different hoof wall regions, aiming at assessment of specialised vascular structures, e.g. vascular sphincter mechanisms and arteriovenous anastomoses. METHODS:The angioarchitecture of the adult pododerma in the equine hoof wall was examined by scanning electron microscopy of micro-corrosion casts assisted by exemplary histological and immuno-histochemical characterisation of the pododermal vasculature. RESULTS:The microvasculature of the lamellae and terminal papillae in all hoof wall regions was described in detail. Focal dilations and microvascular sphincters were a common feature. In contrast to former investigations, true arteriovenous anastomoses were detected at the base of the primary lamellae and the terminal papillae only, while thoroughfare channels proved a regular element within the microvasculature of the wall proper. Bicuspid venous valves were detected as regular feature. For the first time, the alpha-smooth muscle actin-reactivity of the microvascularisation in the hoof wall was systematically assessed, verifying its specialised vasomotor devices. CONCLUSIONS:The vasculature of the hoof wall displays specific angio-adaptations to high pressure and tensile load.
