Abstracts | EQUINE
L . C . R . Smith C . E . Wylie L . Palmer P . H . L . Ramzan
Abstracts | EQUINE
A Longitudinal Study of Fractures in 1488 Thoroughbred Racehorses Receiving Intrasynovial Medication : 2006 – 2011
Background
There is a need for investigation of associations between intrasynovial medication and fracture risk in racehorses .
Objectives
To document the proportion and type of fracture occurring following intrasynovial medication .
Study design
Retrospective longitudinal study .
Methods
Review of clinical records from all Thoroughbred flat racehorses receiving intrasynovial medication under the care of a first‐opinion veterinary practice between 2006 and 2011 . Fractures pre‐ and postmedication were categorised by location , type , and severity ; analysis of fractures sustained within 56‐days of medication was undertaken . Survival analyses using Cox proportional hazards models were conducted for associations between medication used ( corticosteroid vs . non‐corticosteroid ), age at first medication , sex and total number of medications and fracture .
Results
A total of 1488 horses received intrasynovial medication during the period of study ; 8692 synovial spaces were medicated in 3925 sessions . There were 96 fractures that occurred within 56‐days of medication , of which 44 were classified as ‘ serious ’ ( 44 / 1488 ; 3.0 % total population , 95 % CI 2.1 , 3.8 %) and 11 ( 11 / 1488 , 0.7 %, 95 % CI 0.3 , 1.2 %) were euthanased due to severity of injury . Fifty‐four of 96 cases ( 56.4 %, 95 % CI 46.3 , 66.2 %) returned to racing . Targeted imaging of the subsequent injury site was undertaken prior to injury in only 7 ( 7 / 96 , 7.3 %) horses that injured post‐medication . Horses that had received ≥3 previous intrasynovial medication sessions had an increased hazard of sustaining a fracture within 56 days ( HR 2.31 , 95 % CI 1.51 , 3.54 , P < 0.001 ) compared with those receiving ≤3 medication sessions , adjusted for each increasing year of age ( HR 0.67 , 95 % CI 0.53 , 0.86 , P = 0.001 ).
Main limitations
Absence of an unexposed cohort of nonmedicated racehorses .
Conclusions
Serious musculoskeletal injury following intrasynovial medication occurred in 3 % ( 44 / 1488 ) horses . Reduction in injury rates may be possible through greater use of premedication diagnostic imaging .
https :// onlinelibrary . wiley . com / doi / abs / 10.1111 / evj . 12833
• Volume 20 Issue 2 | July 2018 • 27