Shoe configuration effects on third phalanx and capsule motion of hoofs

An interesting in-vitro study on shoeing the horse with laminitis. It suggests that from the standpoint of minimizing distraction forces on P3 and the hoof wall, a heart bar may be the best choice. It does not address one of the main problems I have found with HB: pressure injury at the point of the heart bar. I also wonder if the restricted hoof wall motion that shoeing induces may decrease circulation in the hoof. This all speaks to the complicated nature of hooves with laminitis and that evaluation of treatment is critical: if the horse is more comfortable you are likely on the right track. If the horse is more painful, better reevaluate.
DrO

<b>Shoe configuration effects on normal and laminitic hooves in-situ</b>
PLoS One. 2023 May 8;18(5):e0285475. doi: 10.1371/journal.pone.0285475. eCollection 2023.
Authors
Rita Aoun 1 , Iyana Charles 1 , Abigail DeRouen 1 , Catherine Takawira 1 , Mandi J Lopez 1
Affiliation

1 Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, United States of America.

PMID: 37155654
PMCID: PMC10166494
DOI: 10.1371/journal.pone.0285475

Free PMC article
Abstract

Equine shoes provide hoof protection and support weakened or damaged hoof tissues. Two hypotheses were tested in this study: 1) motion of the third phalanx (P3) and hoof wall deformation are greater in laminitic versus unaffected hooves regardless of shoe type; 2) P3 displacement and hoof wall deformation are greatest while unshod (US), less with open-heel (OH), then egg-bar (EB) shoes, and least with heart-bar (HB) shoes for both hoof conditions. Distal forelimbs (8/condition) were subjected to compressive forces (1.0×102-5.5×103 N) while a real-time motion detection system recorded markers on P3 and the hoof wall coronary band, vertical midpoint, and solar margin. Magnitude and direction of P3 displacement and changes in proximal and distal hemi-circumference, quarter and heel height and proximal and distal heel width were quantified. Hoof condition and shoe effects were assessed with 2-way ANOVA (p<0.05). P3 displacement was greater in laminitic hooves when US or with OH, and EB and HB reduced P3 displacement in laminitic hooves. P3 displacement was similar among shoes in unaffected hooves and greatest in laminitic hooves with OH, then US, EB and HB. EB and HB increased P3 displacement from the dorsal wall in unaffected hooves and decreased it in laminitic hooves. OH and EB increased P3 motion from the coronary band in laminitic hooves, and HB decreased P3 motion toward the solar margin in unaffected and laminitic hooves. In laminitic hooves, HB reduced distal hemi-circumference and quarter deformation and increased heel deformation and expansion. Proximal hemi-circumference constriction was inversely related to proximal heel expansion with and without shoes. Overall, shoe configuration alters hoof deformation distinctly between unaffected and laminitic hooves, and HB provided the greatest P3 stability in laminitic hooves. These unique results about P3 motion and hoof deformation in laminitic and unaffected hooves inform shoe selection and design.