Radiological findings in the proximal sesamoid bones of yearling and 2-year-old Thoroughbred sales horses: Prevalence, progression and associations with racing performance.
Equine Vet J
; 2024 Jan 18.
Article
de En
| MEDLINE
| ID: mdl-38237926
ABSTRACT
BACKGROUND:
Radiological findings in the proximal sesamoid bones (sesamoids) are a persistent source of controversy at Thoroughbred sales, due to inconsistent classification and conflicting assignment of potential clinical importance.OBJECTIVES:
To define the prevalence of sesamoid findings on sales repository radiographs in yearling and 2-year-old Thoroughbreds and to analyse associations with racing performance. To track the changes in sesamoid findings between 1 and 2 years of age in horses that present for sale at both ages. STUDYDESIGN:
Prospective cohort study using an enrolled sample.METHODS:
Horses were enrolled from a 2016 yearling sale and five 2017 2-year-old sales with consignor permission. Radiological findings relating to sesamoid vascular channel appearance, abaxial contour changes and sesamoid fragments were examined. Associations between sesamoid findings and racing performance from 2 to 4 years of age were examined using multivariate regression analyses. Clinical follow-up was sought to ascertain why horses that did not race never started.RESULTS:
A total of 2508 yearlings and 436 2-year-olds were included for evaluation. Interobserver agreement using the new grading system was substantial. Yearling findings associated with a significantly reduced probability of starting a race were Grade 3 vascular channels in forelimb sesamoids (0.52, P < 0.001, 95% confidence interval (CI) 0.37-0.67), abaxial new bone in forelimb sesamoids (0.62, P = 0.01, 95% CI 0.49-0.73), apical or abaxial fragments in forelimb sesamoids (0.55, P = 0.005, 95% CI 0.37-0.72). For affected horses that did race, Grade 3 vascular channels in forelimb sesamoids were associated with fewer race starts (9.9 starts, P = 0.03, 95% CI 8.0-12.2) and Grade 3 vascular channels in hindlimb sesamoids were associated with a delayed start to racing careers (54 days, P = 0.01, 95% CI 20-89). Abaxial new bone in forelimb sesamoids was associated with a 54% reduction in total earnings (P = 0.003, 95% CI 24-72) and a 46% reduction in earnings per start (P = 0.002, 95% CI 21-64). Abaxial concavity occurred predominantly in yearling medial forelimb sesamoids, had no impact on racing performance and mostly resolved by 2-year-old sale. MAINLIMITATIONS:
These findings are applicable to horses presented for sale at public auction and may underestimate the prevalence of severe lesions in non-sales horses.CONCLUSIONS:
Grade 3 vascular channels, forelimb sesamoid abaxial new bone and forelimb sesamoid fragments are important findings in sales repository radiology. The new grading scale assigns a numerical grade for vascular channel appearance that matches the number of enlarged vascular channels evident in a given sesamoid. Abaxial contour changes, when present in sesamoids that are Grade 0 for enlarged vascular channels, are noted separately as either abaxial new bone or abaxial concavity. Fragments are also noted and interpreted separately.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Type d'étude:
Diagnostic_studies
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Langue:
En
Journal:
Equine Vet J
Année:
2024
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique