Incidence of palmar process fractures of the distal phalanx and association with front hoof conformation in foals.

REASONS FOR PERFORMING STUDY: Recent studies indicate a high prevalence of fractures of the palmar processes (PP) of the distal phalanx in foals. However, information on the prevalence of such fractures in different breeds and the effect of predisposing factors, such as hoof conformation, is limited.

OBJECTIVES: To examine the prevalence of distal phalanx PP fractures in foals and report the relationship of distal limb and hoof conformation with the prevalence of fracture.

STUDY DESIGN: Longitudinal study.

METHODS: Front hooves of 19 Thoroughbred, Quarter Horse and Arabian foals were examined. Digital radiographic and photographic images of the distal aspect of the forelimbs were taken at ∼2.5 month intervals. Five radiographic projections of each limb were as follows: lateromedial; horizontal beam dorsopalmar; dorso60°proximal-palmarodistal oblique; dorso60°proximo45°lateral-palmarodistomedial oblique; and dorso60°proximo45°medial-palmarodistolateral oblique. The relationship between measurements and the prevalence of fractures was assessed by 3-way ANOVA.

RESULTS: Fractures were found in 74% (n = 14) of the foals during the study period. The prevalences of lateral PP and medial PP fractures were not significantly different. Several hoof measurements were associated with PP fractures. Longer dorsal length of the distal phalanx was associated with medial PP fractures, while smaller lateral angle and shorter lateral palmar length were associated with a higher prevalence of lateral PP fractures.

CONCLUSIONS: This study revealed a high prevalence of PP fractures in young foals, particularly in Thoroughbred foals. The hoof conformation may be one of the contributory factors to PP fractures in foals.