Sonographic evaluation of the lumbosacral region for neuroaxial anaesthesia in domestic felines

The objective of this study was to describe the lumbosacral region of domestic felines using ultrasonography. The limits and dimensions of the epidural and subarachnoid spaces were identified and their correlation with sex and body score condition (BSC) were evaluated. Fourteen mongrel cat cadavers, nine males and five females, weighing between 2.0 and 4.5 kg and with BCS ranging from 2 to 5 (1–5) were used. The cadavers were put in sternal recumbency and ultrasonographic images of the lumbosacral region were obtained in the sagittal and transverse planes. There was no statistical difference in the measurements between males and females. The BCS was positively correlated with the distance between the skin and dorsal epidural space, the distance between the skin and dural sac, and the distance between the skin and the ventral floor. No correlations were identified between the BCS and the distance between epidural space and dural sac, BCS and the sagittal dural sac height, or BCS and transverse dural sac height. The study showed that animals with a higher body condition score present larger distances between structures, regardless of their sex. In addition, the sonographic study verified the close proximity of the epidural and subarachnoid spaces, highlighting the risk of inadvertent spinal puncture in felines.