Fig. 1

Lateral radiographs (a, b) and a sagittal multiplanar reconstruction (MPR) CT image in bone reconstruction algorithm (c) of the caudal thoracic vertebral column segment in dog no. 13. The radiographs are taken before (a) and after (b) the dog incurred a clinically significant disc extrusion. At the first presentation, three calcified intervertebral discs are identified (arrows) with a moderate degree of calcification in the T9–T10 disc space. At the second presentation, calcification is no longer visible in the T9–T10 disc space (double arrowheads). However, the concurrent CT image (c) shows calcified material in the vertebral canal (open arrow) above a slightly calcified T9–T10 disc space (arrowhead). The CT scan also confirms calcified material in the T10–T11 and T11–T12 disc spaces (solid arrows)