AJVR, Vol 67, No. 9, September 2006 1601 C ervical spondylomyelopathy, also known as wob- bler syndrome, is the most common neurologic disorder of the cervical vertebral column of large-breed dogs. It is characterized by abnormalities of the cervi- cal vertebral column that result in neurologic deficits, cervical hyperesthesia, or both. 1 The disease common- ly affects young Great Danes and middle-aged or old Doberman Pinschers. 2-6 Doberman Pinschers are the most commonly affected breed of dog, accounting for as many as 68% of cases. 7 In CSM, both bony and liga- mentous abnormalities of the caudal cervical vertebral column develop, causing static and dynamic spinal cord compression. It has been proposed that instability has a primary role in the pathogenesis of CSM. 8,9 In Doberman Pinschers, chronic degenerative disk dis- ease seems to be an important factor, so much so that some authors have suggested the term disk-associated wobbler syndrome. 1,10 Canine CSM has similarities with the cervical spondylotic myelopathy of humans, and the Doberman Pinscher breed has been proposed as a model of naturally occurring disease for investiga- tion of the human condition. a There are numerous published articles describing the clinical features and diverse range of treatment methods proposed for CSM, but there is little information regarding its pathogene- sis. 3,9,11,12 A lack of knowledge of the cause, pathogene- sis, and progression of CSM in dogs remains. Results of morphometric or quantitative studies 13-17 of the cervical vertebral column in humans involving MR imaging or postmortem examination have been extensively described. Morphometric investigations increase our understanding of spinal diseases by com- paring anatomic measurements obtained from clinical- ly normal and affected populations. Postmortem and radiographic morphometric investigations 18-22 of the canine cervical vertebral column have been recently conducted. A few quantitative studies 23-25,b of the lum- bosacral, cervical, and thoracic portions of the verte- bral column of dogs have been performed by use of CT Received December 5, 2005. Accepted February 15, 2006. From the Departments of Biomedical Sciences (da Costa, Partlow, LaMarre) and Clinical Studies (Parent, Dobson, Holmberg), Ontario Veterinary College, University of Guelph, Guelph, ON, N1G 2W1, Canada. Dr. da Costa’s present address is Universidade Federal do Paraná, Campus Palotina, Palotina, PR, 85950-000, Brazil. Supported by the Pet Trust Foundation from the Ontario Veterinary College and the Doberman Foundation of America. Dr. da Costa was sponsored by the CNPq–National Scientific Research Council of Brazil. Presented as an abstract at the 23rd Forum of the American College of Veterinary Internal Medicine, Baltimore, June 2005. This report represents a portion of a thesis submitted by the first author to the University of Guelph as partial fulfillment for the PhD degree. Address correspondence to Dr. da Costa. Morphologic and morphometric magnetic resonance imaging features of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy Ronaldo C. da Costa, DMV, PhD; Joane M. Parent, DMV, MVetSc; Gary Partlow, PhD; Howard Dobson, BVM&S, DVSc; David L. Holmberg, DVM; Jonathan LaMarre, DVM, PhD Objective—To compare morphologic and morphome- tric features of the cervical vertebral column and spinal cord of Doberman Pinschers with and without clinical signs of cervical spondylomyelopathy (CSM; wobbler syndrome) detected via magnetic resonance imaging (MRI). Animals—16 clinically normal and 16 CSM-affected Doberman Pinschers. Procedures—For each dog, MRI of the cervical ver- tebral column (in neutral and traction positions) was performed. Morphologically, MRI abnormalities were classified according to a spinal cord compression scale. Foraminal stenosis and intervertebral disk degeneration and protrusion were also recorded. Morphometric measurements of the vertebral canal and spinal cord were obtained in sagittal and trans- verse MRI planes. Results—4 of 16 clinically normal and 15 of 16 CSM- affected dogs had spinal cord compression. Twelve clinically normal and all CSM-affected dogs had disk degeneration. Foraminal stenosis was detected in 11 clinically normal and 14 CSM-affected dogs. Vertebral canal and spinal cord areas were consistently smaller in CSM-affected dogs, compared with clinically nor- mal dogs. In neutral and traction positions, the inter- vertebral disks of CSM-affected dogs were wider than those of clinically normal dogs but the amount of disk distraction was similar between groups. Conclusions and Clinical Relevance—The incidence of intervertebral disk degeneration and foraminal stenosis in clinically normal Doberman Pinschers was high; cervical spinal cord compression may be present without con- current clinical signs. A combination of static factors (ie, a relatively stenotic vertebral canal and wider intervertebral disks) distinguished CSM-affected dogs from clinically normal dogs and appears to be a key feature in the patho- genesis of CSM. (Am J Vet Res 2006;67:1601–1612) ABBREVIATIONS CSM Cervical spondylomyelopathy MR Magnetic resonance CT Computed tomography TR Repetition time TE Echo time FLASH Fast, low-angle shot Gd-DTPA Gadolinium-diethylene triamine pen- tacetic acid