Quantitative morphology of the equine laminar junction in relation to capsule shape in the forehoof of Standardbreds and Thoroughbreds.
BACKGROUND
Differences in hoof morphology have largely been underappreciated in the literature until recently, and it is these that hold the key to interpreting functional adaptation in the hoof.


OBJECTIVE
Primary laminar morphology correlates with hoof capsule shape; and breeds with different hoof shapes and loadings show different patterns of correlation.


METHODS
Seventeen measurements of capsule shape and 3 of primary epidermal laminae (PEL) morphology (spacing, orientation and curvature) were made on right and left front hooves from 27 Standardbred and 25 Thoroughbred horses, and tested for breed differences. Three laminar variables (spacing, orientation and curvature) were measured on each hoof for samples of 25 PEL in 5 circumferential and 4 proximodistal locations. Pairwise correlations of capsular and laminar measurements were compared within breeds. Significant correlations were mapped onto the 20 sampling sites.


RESULTS
Capsule shape differed significantly between breeds in 7 measurements and in a multivariate test. Between breeds, PEL differed in orientation and spacing primarily at the medial quarters and heels, and in curvature at both quarters (P<0.05). Significant correlations between several pairs of capsule and laminar variables were found at sample locations that differed markedly between breeds.


CONCLUSIONS
Laminar morphology, hoof capsule shape and correlations between them differ between Standardbreds and Thoroughbreds. These results support the concept that remodelling of PEL is, at least in part, stimulated and directed by varying stress or strain levels in the laminar junction.


CONCLUSIONS
Understanding the biological responses of hoof tissues to stress should add to the ability to prevent lameness involving the hoof and maintain its health.
Thomason
J J
JJ
Department of Biomedical Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Faramarzi
B
B
Revill
A
A
Sears
W
W
D000222:Adaptation, Physiological; D000818:Animals; D001696:Biomechanical Phenomena; D001947:Breeding; D005260:Female; D005529:Foot Bones / Q000033:anatomy & histology* / Q000502:physiology; D006724:Hoof and Claw / Q000033:anatomy & histology* / Q000166:cytology / Q000502:physiology; D006736:Horses / Q000033:anatomy & histology* / Q000502:physiology; D008297:Male; D012016:Reference Values