Subclinical ultrasonographic abnormalities of the suspensory ligament branches in National Hunt racehorses.
BACKGROUND
Suspensory ligament branch (SLB) desmopathy is a common cause of lameness and an important cause of lost training in the Thoroughbred racing industry. Studies have assessed the impact of insertional injuries of the SLB on the careers of flat racehorses and established the prevalence of subclinical ultrasonographic SLB abnormalities in this population, but little work has investigated SLB injury in National Hunt (NH) racehorses.


OBJECTIVE
To investigate the prevalence of subclinical ultrasonographic SLB abnormalities in NH racehorses with no clinical signs or history of SLB injury and to establish the cross-sectional area (CSA) of SLBs in this population.


METHODS
Cross-sectional study using data collected from horses on an NH yard.


METHODS
Ultrasonographic examination of forelimb SLBs in 62 horses on a single NH yard was performed. Images were graded according to a previously reported system. CSA measurements were obtained from transverse images.


RESULTS
Nineteen of 62 horses had at least one SLB with grade 2 ultrasonographic abnormalities. Grade 2 ultrasonographic abnormalities occurred more frequently in the medial than the lateral SLB (P = 0.05). The medial SLB insertional CSA was significantly larger (P<0.001) than that of the lateral SLB.


CONCLUSIONS
Length of time on the yard (and therefore available veterinary history) is variable in this population.


CONCLUSIONS
One in three NH racehorses without history or clinical signs of SLB injury had at least one SLB with a grade 2 ultrasonographic abnormality. The medial branch was over-represented. The medial SLB insertional CSA is larger than the lateral and thus comparison with the corresponding branch in the contralateral limb is recommended to avoid misdiagnosis of medial SLB enlargement.
School of Clinical Veterinary Science, University of Bristol, Bristol, UK.
A J
AJ
Fairburn
School of Clinical Veterinary Science, University of Bristol, Bristol, UK.
E
E
Busschers
School of Clinical Veterinary Science, University of Bristol, Bristol, UK.
A R S
ARS
Barr
D000818:Animals; D003430:Cross-Sectional Studies; D005552:Forelimb / Q000000981:diagnostic imaging; D006734:Horse Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D006736:Horses / Q000293:injuries*; D008022:Ligaments / Q000000981:diagnostic imaging* / Q000473:pathology; D012420:Running; D013177:Sports; D014463:Ultrasonography / Q000662:veterinary*
National Hunt; horse; subclinical; suspensory ligament branch; ultrasound