Hoof Unevenness in Young Quarter Horses

Researchers at Colorado State University examined hoof shape and unevenness (left-right asymmetry) among 42 2- and 3-year-old Quarter Horses entering training for Western performance. On enrollment into the study, horses were videotaped at a walk and trot for later, subjective evaluation of lameness by three blinded observers. In addition, an inertial sensor system was used for an objective analysis of head and pelvic movement asymmetry as an indication of lameness. Photographs and radiographs were taken of each hoof at 2-month intervals at the time of enrollment and 2, 4 and 6 months into training. These images were digitized for measuring hoof angles and dimensions of structures seen on the lateral, dorsal and solar views. Hoof angles disparate by more than 1.5 degrees were considered uneven. Training included starting the horses with round-pen groundwork for 2 hours a day for 5 days a week over the first 4 months of the study. The horses transitioned to groundwork and riding under saddle during the last 2 months. None of the horses maintained even front or hind feet throughout the study. Overall, 36% of the horses had uneven front feet and 45% had uneven hind feet. Disparate toe angles averaged a 5-degree difference, and there were also heel length and heel angle disparities. There were no significant differences in the incidence of lameness or movement asymmetry among horses with even (12%) and uneven forefeet (16%). There was also no significant difference in the incidence of lameness between…