Overview
The cat has thirteen thoracic vertebrae (T1–T13), one for each pair of ribs. Together with the ribs and the sternum they form the rib cage. The thoracic spine of the cat is very flexible and, with the lumbar spine, takes part in flexing and extending the back during galloping and jumping.
Key features
- Short bodies, with cranial and caudal costal foveae: the head of each rib articulates between two consecutive vertebrae, except in the last ones, where it rests on a single vertebra.
- Short transverse processes, each with a fovea for the tubercle of the rib.
- Spinous processes: tall and sloping caudally in the cranial region and progressively shorter caudally. In the caudal thoracic region (around T10–T11) lies the anticlinal vertebra, whose spinous process is nearly vertical; caudal to it the processes slope cranially, as in the lumbar vertebrae.
- Mammillary and accessory processes: appear on the last thoracic vertebrae, in transition to the lumbar pattern; they are attachment points for the epaxial muscles.
- Vertebral canal: relatively narrow, housing the thoracic spinal cord.
Clinical relevance
- Spinal lymphoma: the most common tumour of the vertebral canal in the cat; it is usually extradural and causes paresis of the pelvic limbs.
- Hypervitaminosis A: the exostoses of deforming spondylosis extend from the neck to the first thoracic vertebrae.
- Trauma: fractures and luxations after road accidents; the anticlinal vertebra and the rib count help to locate the lesion on radiographs.
- Disc herniation: less common than in the dog, although it is described in older cats, mainly in the thoracolumbar region.