An epidural is placed between which vertebrae?

• A. Between L1 and L2
• B. Between L7 and S1
• C. Between C7 and T1
• D. Between T12 and L1

Answer: (B)

In horses, the preferred epidural site for hindquarter anesthesia is the lumbosacral space between the last lumbar vertebra (L7) and the first sacral vertebra (S1). This location is chosen because the spinal cord ends caudally in this species, so accessing the epidural space here allows safe entry and reliable spread of local anesthetic to the pelvic limbs, tail, and perineal region via the caudal nerve roots. Placing the needle cranially (for example between C7–T1 or T12–L1) would affect different regions (forelimbs or trunk) and is not optimal for hindlimb analgesia, while more cranial lumbar sites (like between L1–L2) may be less reliable in reaching the desired areas and carry a higher risk of hitting neural tissue not intended for this block.