Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, UK.
Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, UK; Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada.
J Equine Vet Sci. 2023 Oct;129:104896. doi: 10.1016/j.jevs.2023.104896. Epub 2023 Aug 2.
Flexural and angular limb deformities (LD) are an important cause of early-life morbidity and mortality/euthanasia in Thoroughbred foals. The majority are congenital in origin but, to date, their precise aetiology is poorly understood. We hypothesized that maternal- and pregnancy-level factors, particularly those with potential to influence in-utero growth and development, could play an important role. The aim of this study was therefore to investigate associations between such factors and early-life LD in Thoroughbred foals. A birth cohort was established on seven farms across the United Kingdom and Ireland and details of veterinary interventions for LD in foals in the first six months of life prospectively recorded. Details of dams' signalment, breeding history and reproductive and veterinary history in the breeding season(s) of interest were retrieved retrospectively from stud farm and veterinary records. Associations between mare- and pregnancy-level factors and LD in offspring were assessed using multivariable logistic regression. Records were available for 275 pregnancies in 235 mares, over two breeding seasons. Pregnancies resulted in the birth of 272 live foals, 21% of which (n = 57/272, 95% CI, 16-26) required veterinary intervention for LD in the first six months of life. Odds of LD decreased by 4% per day increase in gestation length between 314 and 381 days (OR 0.96, 95% CI, 0.93-0.99, P = .01). Longer gestation length appears to reduce the odds of early-life LD, including within the normal range of gestation length for Thoroughbred foals. Further work is required to elucidate biological mechanisms behind this association.
弯曲和角度肢体畸形（LD）是导致纯种马驹早期生活发病率和死亡率/安乐死的重要原因。大多数是先天性的，但迄今为止，其确切病因尚不清楚。我们假设母体和妊娠水平的因素，特别是那些可能影响宫内生长和发育的因素，可能起着重要作用。因此，本研究旨在调查这些因素与纯种马驹早期生命 LD 之间的关联。在英国和爱尔兰的七个农场建立了一个出生队列，并前瞻性地记录了在生命的前六个月内，马驹 LD 的兽医干预细节。从马厩和兽医记录中回顾性地检索了有关配种季节中母马的特征、配种史以及生殖和兽医史的详细信息。使用多变量逻辑回归评估了母体和妊娠水平因素与后代 LD 之间的关联。在 235 匹母马的两个配种季节中，有 275 次妊娠记录。这些妊娠导致了 272 匹活驹的出生，其中 21%（n=57/272，95%CI，16-26）在生命的前六个月需要兽医干预来治疗 LD。妊娠长度每增加一天，LD 的可能性就会降低 4%（OR 0.96，95%CI，0.93-0.99，P=0.01）。在 314 至 381 天之间，妊娠长度增加似乎会降低早期 LD 的可能性，包括在纯种马驹的正常妊娠长度范围内。需要进一步的工作来阐明这种关联背后的生物学机制。
