Graduate Research Assistant Department of Veterinary Clinical Sciences, Louisiana State University Baton Rouge, Louisiana
Investigation of the Shoe Configuration Effect on the Third Phalanx Motion in Unaffected Versus Laminitic Equine Hooves. Aoun R1, Wang P<sup>1, Takawira C1, Osborn M2, Lopez MJ1. 1Louisiana State University, Department of Veterinary Clinical Sciences, Baton Rouge, LA; 2Louisiana State University, Comparative Biomedical Sciences, Baton Rouge, LA.
Laminitis damages the equine hoof laminae and can progress to rotation/sinking of the third phalanx (P3). Therapy often includes supportive shoeing. The hypothesis tested in this project was that shoe configuration affects P3 displacement differently in unaffected versus laminitic hooves. The proximal phalanges of six disarticulated equine forelimbs were embedded in resin within fixtures designed to reproduce the stance fetlock angle after fixation of the proximal interphalangeal joint. Force (up to 5500 N) representing the stance phase at a walk was applied to unaffected and laminitic hooves using a mechanical testing system. A real-time motion detection system recorded 3D Cartesian coordinates of markers on hoof landmarks, P3, dorsal hoof wall (HW), coronary band (CB), and solar margin (SM). Hoof landmark displacement with and without standard, heart-bar and egg-bar shoes was compared with a repeated measurement analysis. Displacement of P3, HW, CB, and SM increased with increasing load. Unlike standard shoes, egg-bar and heart-bar shoes decreased P3 displacement in laminitic hooves. P3 moved toward the solar margin with standard and egg-bar shoes. With heart-bar shoes, P3 moved toward the heel of unaffected hooves and toward the dorsal hoof wall of laminitic hooves. Results highlight the shoe configuration’s influence on the amount and direction of P3 motion in unaffected versus laminitic hooves. This study was limited by low sample size and results only apply to the tested shoes. Study results highlight the distinct impact of shoe configuration on unaffected and laminitic hoof tissue that should be considered for hoof protection and stabilization.