Radiographic vertebral canal and vertebral body ratios in Doberman Pinschers with and without clinical signs of caudal cervical spondylomyelopathy

Objective-To determine radiographic vertebral ratio values representing vertebral canal stenosis in Doberman Pinschers with and without clinical signs of caudal cervical spondylomyelopathy (CCSM). Animals-Doberman Pinschers with (n = 81) and without (39) signs of CCSM. Procedures-All dogs underwent lateral survey radiography of the cervical vertebral column. Five specific measurements were made at C3 through C7, and from those data, 3 ratios were calculated and analyzed for use in diagnosis of CSSM: canal height-to-vertebral body height ratio (CBHR), canal height-to-vertebral body length ratio (CBLR), and caudal vertebral canal height-to-cranial vertebral canal height ratio (CCHR). The CBHR and CBLR were considered indicators of vertebral canal stenosis, and CCHR described vertebral canal shape. Results-Compared with Doberman Pinschers without CCSM, mean CBHR and CBLR values were significantly smaller for Doberman Pinschers with CCSM; for CBHR, this difference was evident at each assessed vertebra. The CCHR value for C7 was significantly larger in dogs with CCSM. Receiver operating characteristic statistics did not identify a threshold point that had combined high sensitivity and specificity sufficient to differentiate between Doberman Pinschers with and without CCSM. Conclusions and Clinical Relevance-Doberman Pinschers with CCSM had vertebral canal stenosis combined with a funnel-shaped vertebral canal at C7 significantly more often than did Doberman Pinschers without CCSM. Despite these significant differences, no reliable threshold ratio values were identified to differentiate groups of dogs.