The effects of trimming on foot morphology - A comparative study of various hoof care models (Brian Hampson)

Introduction

There are at least several models of practice for equine hoof care which all claim to produce desirable outcomes for the foot health of horses (Jackson 1997, O’grady 2003, Ovnicek 1995, Ovnicek 2003, Strasser 2004). These models are based, among other factors, on certain morphological features of the hoof capsule that can be manipulated by nipping and rasping the sole and hoof wall, the application of a variety of external devices including horse shoes, and encouraging new hoof capsule growth in a predictable pattern. While proponents of the various models are confident in their particular methods and claim anecdotal evidence of their successful application, there appears to be little published evidence of the comparison of the effectiveness of methodologies in obtaining morphological changes to the hoof capsule and therefore affecting foot health and function. Clayton et al (2011) documented hoof capsule morphological changes in response to one model of hoof trimming and determined that these changes can be observed and accurately measured in both the short and long term. This methodology can be employed in a comparative study to document the responses of the equine hoof capsule to a variety of hoof care models. The determination of these responses may allow those people responsible for horse husbandry to make better informed decisions regarding hoof care options available to them. 

Methodology

The response of hoof capsule morphology to eight models of hoof care practice will be investigated in a multi-site comparative study over a 12 month period. The methodology of Clayton et al (2011) will be followed at each location to ensure consistency in methods.

Subjects: Six mixed-breed horses used for recreational purposes at each of eight locations (n=48). Prior to commencement of the study each horse will have received no particular formal hoof care model for the previous 12 months and not be trimmed for at least the previous six weeks.

Models/locations: Each of the eight locations will represent one of the eight hoof care models. Each horse in each location will receive the same hoof care from the same practitioner but the model of hoof care will vary between locations. Feet will be managed at least six week intervals for the duration of the study.

Procedure: Measurement of hoof capsule morphology will closely follow the methodology of Clayton, et al (2011). Morphology will be determined by two independent and blinded observers. Digital measurements will be taken from calibrated and standardised digital photographs and radiographs of the left forefoot. This will include photographic dorsal, lateral and solar views and latero-medial radiographic view. Morphology will be measured on day 1, prior to the first intervention, and at the four-month and 12-month time lines.