Prospective case series of Standardbred racehorses treated with intra-lesional ultrasound-guided injection of platelet-rich plasma for suspensory ligament branch injuries

Abstract Standardbred racehorses are frequently diagnosed with suspensory ligament branch injuries which results in loss of earnings and morbidity. This prospective study aims to measure outcomes for suspensory ligament branch desmitis (SLBD) in Standardbred racehorses treated with intra-lesional platelet rich plasma (PRP). All Standardbred racehorses presented at the Vets On Wheels clinic in Marsa between 01.10.2019 and 31.12.2020 with grade 2-3 SLBD diagnosed ultrasonographically were included. All core lesions were injected with PRP under ultrasound guidance following standardised blood collection and centrifugal processes. All horses underwent a standardised rehabilitation protocol. Racing data including number of starts and earning following treatment was retrieved from the Malta Racing Club database. Twelve Standardbred racehorses were included in the study with a mean age of 9 years (range; 6 – 12). Forelimb lesions accounted for 36% of injuries. Seven horses (58%) returned to racing, although only two (17%) started more than two races. The average time elapsed between treatment and date of first start was 200 days. To the authors knowledge this is the first study to examine SLBD outcomes following PRP treatment in Standardbred racehorses. Older racing Standardbreds with grade 2/3 SLBD have a guarded prognosis for return to racing, as documented within racing Thoroughbred populations. Whether or not intra-lesional PRP alters the prognosis cannot be ascertained from this study.