EFFICACY OF THE NEW RADIOGRAPHIC MEASUREMENT METHOD FOR CERVICAL VERTEBRAL INSTABILITY IN WOBBLING FOALS

Cervical myelography and survey radiography was performed on 12 light breed wobbling foals and a new radiographic measurement method was app lied for more accurate diagnosis of cervical vertebral instability. Ra tios of stenosis of the spinal canal on survey radiography and myelogr aphy using relative values in an individual foal were defined on radio grams of lateral flexed position of mid-cervical region, and coinciden ce between the ratios and histopathological lesions in the cervical sp inal cord was investigated. Five of 6 foals had ratios of stenosis on myelography more than 40% at the intervertebral sites where the most s evere histopathological lesions were observed. Four of 6 foals had rat ios of stenosis on survey radiography more than 40% at the interverteb ral sites where the most severe histopathological lesions were observe d. False-positive diagnosis of CVI was observed in I out of 6 foals wi thout histopathological lesion when both ratios of stenosis on myelogr aphy and survey radiography were applied. Although the standard value of 40% should be further investigated, the new radiographic measuremen t method in this study is very useful in clinical diagnosis of cervica l vertebral instability in wobbling foals, and the presence of lesions in the cervical spinal cord and their sites by survey radiography may be estimated more accurately.