Hoof Capability of Barefoot-Kept Horses and Ponies Walking over Artificial Environments: An Anatomical and Radiological Study

Abstract

Hoof capability of domesticated, barefoot-kept horses and ponies traversing artificial environments remains undocumented. In this study, four equines were walked in-hand for 16 days, covering a distance of 50 km, over three solid surfaces. Subsequently, we conducted an assessment of hoof morphology. Hooves (n = 16) were radiographed before and after the trial, spaced 3 weeks apart, for sole depth measurement. External measurements of feet were recorded 24 hours before day 1 and repeated on day 9. Radiographs revealed increased sole depth in 11 hooves, notably at the palmar process, and some misalignment in certain phalanges. On day 9, after a 36-km distance, all hooves exhibited calloused soles and frogs, and required trimming. The front hooves of the horses had a pronounced, natural concavity. Hard surfaces were found to stimulate sole growth, with a portion of sole thickness preferentially accumulating within the dermal zone. Collectively, the maintenance of short trimming cycles to prevent misalignment, minimize hoof-wall loading and maintain a load-sharing system, may be necessary for barefoot-kept horses considering their rapid growth rate.