Comparative ultrasonographic characterization of the pelvis in clinically normal horses and donkeys

This study was conducted to provide detailed a comparative ultrasonographic description of the pelvis in clinically normal horses and donkeys. It was carried out on 48 mature animals (30 horses and 18 donkeys). Evaluation of the pelvis was performed using transcutaneous and transrectal techniques. The following structures were examined: the tubera sacrales (the shape and distance between them and the distance between each of them and the first sacral spinous process), the ilial wing, the tuber coxae, the ilial body, the hip joint, the tuber ischii, the third trochanter, the appearance and measurements of the dorsal and lateral parts of the dorsal sacroiliac ligament and the thoracolumbar fascia, the ischiatic table, the obturator foramen and its contents, the pubis, the medial aspect of the acetabulum and the ilial body, the sacroiliac joint and the ventral aspect of the sacrum. For each evaluated structure, the results obtained were compared between horses and donkeys. A high correspondence was found between the pelvises of horses and donkeys concerning their ultrasonographic appearance and measurements, except for the cross sectional area of both dorsal parts of the dorsal sacroiliac ligament-thoracolumbar fascia combination, and the sacroiliac joint width, where there were significant differences between them.