Canine Congenital Spinal Malformations Study Guide

Overview and Clinical Importance

Congenital spinal malformations (CSMs) represent a group of developmental abnormalities affecting the vertebral column that are present at birth. These conditions range from clinically insignificant incidental findings to severe, life-threatening spinal cord compression. Understanding the pathophysiology, breed predispositions, clinical presentation, and treatment options for these conditions is essential for the NAVLE examination and clinical practice.

The major congenital spinal malformations covered in this guide include hemivertebrae, butterfly vertebrae, block vertebrae, transitional vertebrae, atlantoaxial instability (AAI), and cervical spondylomyelopathy (CSM/Wobbler syndrome). These conditions have significant breed predispositions, with brachycephalic screw-tailed breeds and toy breeds being most commonly affected by certain malformations, while large and giant breeds are predisposed to others.

Embryological Basis of Vertebral Development

Understanding vertebral embryology is essential for comprehending the pathogenesis of congenital malformations. Each vertebral body develops from two paired sclerotomal masses that migrate from the somites to surround the notochord. These paired structures normally fuse and ossify during fetal development to form normal vertebrae.