Anatomic description of the basivertebral nerve and meningeal branch of the spinal nerve in the dog

Abstract

Purpose: The existence of the basivertebral nerve and meningeal branch of the spinal nerve has not been proven in dogs to date. The objectives of this study are to 1) determine whether dogs have a meningeal branch of the spinal nerve (MBSN) and a basivertebral nerve (BVN) and to (2) describe anatomical characteristics of these two nerves. Authors also put forward a discussion on the possible clinical relevance of these findings. Material and methods: Dissections were performed on six embalmed dogs at the Veterinary Faculty of Barcelona with the use of stereomicroscopy and microsurgery equipment. Results: The MBSN (grossly) and BVN (grossly and histologically) were identified in the cervical, thoracic, and lumbar region in all dog specimens. In addition, other small fibers (suspected nerves) entering the vertebral body through small foramina close to the end plates were identified. Histological examination of the tissues confirmed the presence of nerve fibers (myelinated and unmyelinated) in suspected BVN samples. Results of the present study indicated that dogs have BVNs. Also, suspected nerve fibers were identified among the epidural fat, running from the intervertebral foramina, that likely represent the MBSN. Conclusion: These findings open up the discussion on extrapolation of treatment options employed in human medicine for “low back pain”, such as BVN ablation, which is discussed in this article. Further anatomic and clinical studies of the innervation for the vertebral body, periosteum, vasculature, dorsal longitudinal ligament and anulus fibrosus are necessary to elucidate possible anatomical variants and breed differences as well as potential clinical (e.g., therapeutic) relevance.