Ultrasound image obtained after injection in a canine carcass during quadratus lumborum block (QLB). The picture shows hydrodissection of the quadratus lumburom muscle from the psoas muscle and the thoracolumbar fascia, illustrating that the QLB block was successful. TP, transverse process of L2 vertebrae; VB, vertebral body of L2 vertebrae; QLM, quadratus lumborum muscle; PM, psoas muscle; LA, mixture of contrasts; TLF, thoracolumbar fascia.