Relationships between the shape of the hoof capsule and orientation of the distal phalanx in long toe underrun heels in donkeys

Background: There is limited information on the morphology, radiography and orientation of the distal phalanx in the hoof capsule in long toe underrun heels in donkeys. Objectives: This study aimed to determine the relationships between the hoof capsule shape and distal phalanx radiographic parameters. Study design: Post-mortem collected feet. Methods: A total of 68 cadaver front hooves with long toe underrun heels were used in the study. Lateral photographic and lateromedial radiographic parameters of the feet were obtained. Results: The mean hoof wall angle (HWA) was strongly significantly correlated with heel angle (HA), dorsal HWA, HA measured through radiography and distal phalanx to toe distance and was modestly correlated with distal phalanx angle, solar border of the distal phalanx angle, coronet angle and distal phalanx to frog distance. The linear hoof wall length (HWL) and heel length showed a strong and modest significant correlation with distal phalanx to bottom, dorsal HWL and distal phalanx to toe distance. Main limitations: The feet included in the study were obtained from many yards and different body sizes. Conclusions: This study supports an association between radiographic and morphologic parameters in long toe underrun heels. The strong and modest correlations between measured photographic and radiographic parameters may indicate the relationships between the hoof capsule shape and distal phalanx orientation.