Abstract:
The incidence and types of catastrophic musculoskeletal injuries in Thoroughbreds that
resulted in euthanasia on selected racetracks in South Africa between 1998 and 2012 were
investigated by an observational retrospective investigation. Data from the National
Horseracing Authority of Southern Africa for these racetracks were used to calculate
incidence rates in Thoroughbreds (n = 114) that sustained catastrophic musculoskeletal
injuries during racing that required immediate euthanasia, based on the diagnosis made by
the on-site veterinarian as well as on fetlock radiographs and dissections of 53 cadaver limbs
of horses that sustained a catastrophic musculoskeletal injury. The proximal sesamoid bones
and the distal suspensory ligament were involved in 55.26% of horses; 73.58% of the cadaver
limb radiographs were of the left forelimb, 64.15% were closed fractures, and 74.47% had
biaxial proximal sesamoid bone fractures. Catastrophic musculoskeletal injuries occurred
almost exclusively unilaterally and involved mostly the left front leg. The average incidence
rate for a catastrophic musculoskeletal injury occurring in a year at any of the tracks was
0.6 of 1000 starts.
