Limb Deformities in Standardbred Foals

Limb Deformities in Standardbred Foals. There is limited knowledge of the prevalence of congenital limb deformities in New Zealand horse populations. Risk factors under New Zealand management conditions have not been identified to date. The objectives of this study were to describe the prevalence of congenital limb deformities in foals at birth on two commercial Standardbred stud farms in New Zealand and to investigate associated risk factors. Data were collected on 1,189 foals during the 2004/05 and 2005/06 breeding seasons from which limb deformitiy data had been routinely collected within one week of birth. A visual, clinical inspection was conducted on all foals for congenital limb deformities by an experienced clinician. Foals were described as either having a limb deformity or not,there was no grading of severity. Possibly because of the binary scoring system used, and the examination of the foals within a few days of birth, there was a high proportion of foals in this study scored with some form of limb deformity (LD) (36%). Contracted tendons were the most commonly reported LD at birth (26%) and tendon laxity (20%) and angular limb deformities (19%) were also commonly reported. There were differences in the prevelence between farms, the different years and the foal’s month of birth, indicating nutrition and management factors may be associated with congenital limb deformities. In a subset of these foals (n = 627, those old enough to have race records up to the end of their 3 year old racing season) the presence or absence of a LD within one week of birth was examined against specific racing and training milestones. There was no signficant negative effect of the presence of LD at birth and the attainment of racing and training milestones. This reinforces the observation that many of the LD scored in this study were mild and would resolve with normal growth and development. Dr Chris Rogers, Massey University. Miss Nikita Stowers.