The Hoof Renewal Time of Thoroughbred Foals from Birth

Abstract

IntroductionThoroughbred foals are born with fully developed hooves and stand within minutes. A ring in the horn occurs at birth and grows down the hoof wall, marking the fetal hoof (distal) and foal hoof (proximal). Birth rings in hoof horn have been noted in other species and used to estimate age. Hoof wall renewal in all ages of horse has been poorly reported; horn growth and complete hoof capsule renewal has not been measured in Thoroughbred foals. Partial hoof wall avulsions are relatively common. The objective was to measure the time taken for the fetal hoof of a newborn foal to grow out and be replaced by hoof grown since birth.MethodsThoroughbred foals (N = 150) on four Newmarket stud farms were studied during June to September. The age of the foal and the day that routine hoof trimming removed the remnants of the fetal hoof of the front hooves was recorded. Foals that were on restricted exercise, ill or where the remnants of the fetal hoof still remained after trimming were excluded from the data. 45 foals fulfilled the criteria. The data were tabulated in Excel, analysed in Minitab and assessed for normality (Anderson‐Darling).ResultsThe mean age at which the fetal hoof grew out was 145 ± 15 days (95% confidence interval, 141.77–147.16).ConclusionsThoroughbred foals replace the fetal hoof at twice the speed given for mature horses (270–365 days). Knowing the time of hoof renewal will allow accurate predictions of healing to be made in cases of partial hoof wall avulsion and other hoof lesions.Ethical Animal ResearchApproval was given by the University of Central Lancashire Animal Projects Committee. Explicit owner informed consent for participation in this study is not stated. Sources of funding: none. Competing interests: none.