Perform a proximal paravertebral block by placing local anesthetic just off the midline and caudal to the transverse processes of T13, L1, and L2 vertebrae.
With a distal paravertebral block, inject the local above and below the ends of the transverse processes of L1, L2, and L4 vertebrae.
Target the spinal nerves (T13, L1, and L2) using a paravertebral block to completely desensitize the flank of a cow.
Note the difference: proximal at T13, L1, and L2 vs. distal at L1, L2, and L4. However, the same nerves are desensitized because they gradually course caudally after exiting their spinal foramen.
Proper placement results in warming of the skin from vasodilation, anesthesia of the skin and body wall, and a curvature of the spine in some cows. The latter is caused by relaxation of the epaxial musculature on the affected side; the spine curves towards the opposite side.
Click here to see a good summary on Local Anesthesia and Analgesia by Lyon Lee DVM, PhD, pp. 12-14.
