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.

Iron-Rich Basal Sediments from the Eastern Equatorial Pacific: Leg 16, Deep Sea Drilling Project

Iron-rich sediments chemically similar to those forming at present on the crest of the East Pacific Rise have been found just above basement at widely separated drill sites in the eastern equatorial Pacific, including three sites of Leg 16 of the Deep Sea Drilling Project. These sediments were probably formed when the basement was at the crest of this rise and have moved to their present location as a result of sea-floor spreading.