Objective—To evaluate horseshoe characteristics
and high-speed exercise history as risk factors for catastrophic
musculoskeletal injury in Thoroughbred
Animals—377 horses (37,529 race starts).
Procedure—Shoe characteristics included material,
toe grab height, heel traction device, pads, and rim
shoes. Racing variables were obtained from a computerized
database. Forty-three horses that had a
musculoskeletal injury and then failed to race or train
for 6 months (cases) and 334 noninjured horses from
the same race in which a horse was injured (controls)
were compared regarding risk factors.
Results—Overall, 98% of race starts were associated
with aluminum shoes, 85% with toe grabs, 32% with
pads, and 12% with rims on forelimb horseshoes.
Among 43 horses with musculoskeletal injury, sex
(geldings), an extended interval since last race, and
reduced exercise during the 30 or 60 days preceding
injury were risk factors for catastrophic injury. Odds
of injury in racehorses with toe grabs on front shoes
were 1.5 times the odds of injury in horses without
toe grabs, but this association was not significant
(95% confidence interval, 0.5 to 4.1).
Conclusions and Clinical Relevance—Results suggest
that horses that return to racing after an extended
period of reduced exercise are at high risk of catastrophic
musculoskeletal injury. Results regarding the
use of toe grabs as a possible risk factor for catastrophic
injury were inconclusive because the probability
of declaring (in error) that use of toe grabs was
associated with an increased risk of musculoskeletal
injury (eg, odds ratio > 1.0) was 38%. (Am J Vet Res 2005;66:1314–1320)