Stigen Øyvind, Ciasca Taizha, Kolbjørnsen Øyvor
Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Sentrum, P.O. Box 369, 0102, Oslo, Norway.
Department of Pathology, National Veterinary Institute, Sentrum, P.O. Box 750, 0106, Oslo, Norway.
Acta Vet Scand. 2019 Mar 8;61(1):13. doi: 10.1186/s13028-019-0448-2.
Three Nordic countries have national breeding programs to reduce the frequency of intervertebral disc disease in dachshunds. The programs include a radiographic examination of the vertebral column and dachshunds with more than four calcified discs visible on radiographs (CDVR) are discouraged from use in breeding. However, disc extrusion is also diagnosed in dachshunds without CDVR. The utility of the breeding programs is therefore questioned.
A prospective study of 25 dachshunds surgically treated for disc extrusion was conducted. For all the dogs, preoperative radiographs were evaluated for detectable disc calcifications and preoperative computed tomography (CT) scans were evaluated for presence of calcified material in the vertebral canal. Postoperatively, extruded disc material was examined for degeneration and calcification by histology. Diagnostic imaging and histology were done independently. Radiographically visible calcification was identified in 17 (68.0%) of 25 extruded discs. Calcification was seen in the disc space for all these 17 discs, and for eight of the 17, there was also calcified material visible in the vertebral canal. Extruded material from all the 25 discs was found to be calcified, both by CT and histopathology.
In dachshunds with acute disc extrusion, radiographically visible calcification will frequently be found in the affected disc space, but not all affected disc spaces contain radiographically visible calcification. Using histopathology as the gold standard, a sensitivity of 0.3 (8/25) for radiography and 1.0 (25/25) for CT was found for detecting calcified disc material in the vertebral canal. Further, a sensitivity of 0.7 (17/25) was found for radiography for detecting remaining calcified material in the disc space. Thus, extruded disc material should be considered to be calcified, even in the absence of radiographically visible calcification.
三个北欧国家设有全国性育种计划，以降低腊肠犬椎间盘疾病的发生率。这些计划包括对脊柱进行X光检查，X光片上可见超过四个钙化椎间盘的腊肠犬（CDVR）不鼓励用于繁殖。然而，在没有CDVR的腊肠犬中也会诊断出椎间盘突出。因此，育种计划的效用受到质疑。
对25只接受椎间盘突出手术治疗的腊肠犬进行了一项前瞻性研究。对所有犬只，术前X光片评估可检测到的椎间盘钙化情况，术前计算机断层扫描（CT）评估椎管内钙化物质的存在情况。术后，通过组织学检查突出的椎间盘材料的退变和钙化情况。诊断成像和组织学检查独立进行。在25个突出的椎间盘中，17个（68.0%）在X光片上可见钙化。这17个椎间盘的椎间盘间隙均可见钙化，其中8个在椎管内也可见钙化物质。通过CT和组织病理学检查发现，所有25个椎间盘的突出材料均有钙化。
在患有急性椎间盘突出的腊肠犬中，受影响的椎间盘间隙经常会在X光片上可见钙化，但并非所有受影响的椎间盘间隙都有X光片可见的钙化。以组织病理学作为金标准，X光检查检测椎管内钙化椎间盘材料的敏感性为0.3（8/25），CT的敏感性为1.0（25/25）。此外，X光检查检测椎间盘间隙中剩余钙化物质的敏感性为0.7（17/25）。因此，即使没有X光片可见的钙化，突出的椎间盘材料也应被视为有钙化。
