Hoof size, shape, and balance as possible risk factors for catastrophic musculoskeletal injury of Thoroughbred racehorses.
OBJECTIVE
To evaluate hoof size, shape, and balance as risk factors for catastrophic musculoskeletal injuries (CMI), including suspensory apparatus failure (SAF) and cannon bone condylar fracture (CDY) in Thoroughbred racehorses.


METHODS
95 Thoroughbred racehorses that died between 1994 and 1996.


METHODS
38 quantitative measures of hoof size, shape, and balance were obtained from orthogonal digital images of the hoof and were compared between case horses with forelimb CMI (70), SAF (43), and CDY (10) injuries and control horses whose death was unrelated to the musculoskeletal system (non-CMI, 25). Comparison of group means between cases and controls was done using ANOVA, and multivariable logistic regression was used to estimate odds ratios.


RESULTS
Odds of CMI were 0.62 times lower for a 5mm increase in ground surface width difference and 0.49 times lower for a 100-mm2 increase in sole area difference. Odds of SAF were 6.75 times greater with a 10 degrees increase in toe-heel angle difference and 0.58 times lower with a 100-mm2 increase in sole area difference. Odds of CDY were 0.26 times lower with a 3 degrees increase in toe angle, 0.15 times lower with a 5-mm increase in lateral ground surface width, and 0.35 times lower with a 100-mm2 increase in sole area difference.


CONCLUSIONS
Decreasing the difference between toe and heel angles should decrease risk of SAF for Thoroughbred racehorses and should be considered in addition to increasing toe angle alone to help prevent catastrophic injury. Trimming the hoof to perfect mediolateral symmetry may not be a sound approach to avoiding injury.
Kane
A J
AJ
Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis 95616, USA.
Stover
S M
SM
Gardner
I A
IA
Bock
K B
KB
Case
J T
JT
Johnson
B J
BJ
Anderson
M L
ML
Barr
B C
BC
Daft
B M
BM
Kinde
H
H
Larochelle
D
D
Moore
J
J
Mysore
J
J
Stoltz
J
J
Woods
L
L
Read
D H
DH
Ardans
A A
AA
D000818:Animals; D001265:Athletic Injuries / Q000453:epidemiology / Q000662:veterinary*; D001842:Bone and Bones / Q000293:injuries*; D005260:Female; D006724:Hoof and Claw / Q000033:anatomy & histology*; D006734:Horse Diseases / Q000453:epidemiology*; D006736:Horses / Q000033:anatomy & histology* / Q000293:injuries*; D008297:Male; D018482:Muscle, Skeletal / Q000293:injuries*; D009919:Orchiectomy; D011187:Posture; D012307:Risk Factors