Kinematics of induced reversible hind and fore hoof lamenesses in horses at the trot

Abstract

SummaryThis study determined differences in hoof motion patterns of the trot between mild fore hoof lameness, mild hind hoof lameness and sound control conditions. Six sound Dutch Warmblood mares were shod with 4 steel shoes to which were welded 2 nuts inside the medial and lateral branches of the 2 right shoes. Into each nut was seated a vertical bolt which could be adjusted to alter pressure upon the hoof sole, producing transitory lamenesses of variable magnitude. Treatments were a sound control condition; a mild fore hoof lameness; a mild hind hoof lameness and another sound control following either lameness treatment. Videotapes (60 Hz) were taken from a camera aimed perpendicularly to the line of horse motion, with a metrestick taped as a reference distance. Horses were hand led at the trot for 6 trials under each treatment. A split‐plot in time model was used in an analysis of covariance, allowing treatment comparisons on an equivalent‐velocity basis. Velocities averaged 3.413 ± 0.027 m/s (mean ± s.e.); stride lengths 2.172 ± 0.017 m and stride durations 0.638 ± 0.004 s. Horses slowed and shortened their strides during lameness treatments without changing stride duration. Changes in the motion patterns of all 4 hooves occurred during fore and hind hoof lamenesses, reflecting a redistribution of weightbearing onto the 3 sound limbs. Several hoof kinematic variables measured in this study differed between mild hind and fore lamenesses but fewer variables differentiated mild lamenesses from sound conditions. The information gained from this study will be important in developing objective image‐based equine lameness diagnostic techniques.