It is clinically useful to know the approximate locations of spinal cord segments relative to palpable, radiographically visible vertebrae. One learning strategy is to remember the following four relationships and then interpolate other position relationships as necessary. (The illustrated relationships are the most common for medium and large dogs (± half vertebra). In small dogs the position is one vertebra caudal to that shown.)
A. The cervical enlargement (brachial plexus segments) are centered at the C6-C7 intervertebral disc.
B. At the thoraco-lumbar junction, segments are positioned within nominally corresponding vertebrae.
C. The three sacral segments are located within the L5 vertebra.
D. The spinal cord terminates at the L6-L7 intervertebral disc.