Overview
The dog has seven cervical vertebrae. The atlas (C1), the axis (C2) and the seventh (C7) are distinctive; the third to sixth share a similar plan and are described together here. They are the longest vertebrae of the column after the axis, and their length decreases slightly from C3 to C6.
Key features
- Body (corpus vertebrae): long, with a convex cranial end (head) and a concave caudal end (fossa). A ventral crest runs along its ventral surface.
- Vertebral arch and canal: wide, housing the cervical intumescence of the spinal cord in the caudal part of the neck.
- Spinous processes: low in C3 and C4, becoming progressively taller towards C7.
- Transverse processes: large and divided into dorsal and ventral parts. At their base lies the transverse foramen (foramen transversarium); the series of foramina forms the transverse canal for the vertebral artery and vein. In C6 the ventral part forms a broad plate, the ventral lamina (lamina ventralis), a landmark on radiographs.
- Articular processes: large, with nearly horizontal articular surfaces that allow wide lateral and dorsoventral movement of the neck.
Clinical relevance
- Cervical intervertebral disc disease: most frequent at C2–C3 and C3–C4 in small chondrodystrophic breeds (dachshund, beagle); it causes intense neck pain, often with few neurological deficits.
- Cervical spondylomyelopathy (wobbler syndrome): compression of the caudal cervical spinal cord (C5–C7) by malformed vertebrae, hypertrophied ligaments or disc protrusion in large and giant breeds (Dobermann, Great Dane), causing ataxia that is most obvious in the pelvic limbs.
In this model C3–C6 are reconstructed by deforming the scanned seventh cervical vertebra; their outline is approximate.