Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in South Korea (2015-2019)

Superficial digital flexor (SDF) tendinopathy is one of the most common musculoskeletal diseases in Thoroughbreds and a major cause of retirement from racing among racehorses in South Korea. However, there are no previous epidemiological studies on SDF tendinopathy-related risk factors for racehorses in South Korea. The interventions derived from such a study could reduce the occurrence of SDF tendinopathy and, therefore, extend horses' racing careers.

To identify the risk factors associated with SDF tendinopathy for Thoroughbreds in South Korea.

Retrospective case-control study (2015-2019).

A total of 101 Thoroughbreds that were diagnosed with SDF tendinopathy following a recorded fast-exercise (training gallop, trial racing, racing) between 2015 and 2019 were included in the study. Additionally, 304 healthy Thoroughbreds (319 events) with at least one recorded fast-exercise between 2015 and 2019 were also included as controls. Multivariable logistic regression was used to identify risk factors for SDF tendinopathy.

SDF tendinopathy was significantly more likely to be diagnosed after racing or trial racing than after galloping. Horses with lower grades (6, ungraded) based on racing performance were associated with a higher risk of SDFT injuries. An increased risk of SDFT injury was observed with fewer gallop training days in the previous 60 days to the last fast-exercise, more canter training days in the previous 180 days, or having a period of no fast-exercise for over 90 days in the year prior to the event.

Information on the distance and speed of gallop training was not available.

The implementation of risk profiling and other preventive measures for horses with fewer gallop training days before racing could help minimise the number of horses sustaining SDF tendinopathy.