The purpose of this study was to report the normal ultrasonographic appearance and spinal cord sagittal diameter of canine neonates. Longitudinal and transverse scans were done on 11 clinically normal canine neonates were performed at 3, 10, 20 and 30 days of age, using 8-10 MHz linear transducer. Measurement of the spinal cord sagittal diameter was recorded at different spinal segments. The spinal cord was recognized as an anechoic to hypoechoic tubular structure within the spinal canal, the three meningeal layers enclosing the cord were identified as hyperechoic dura and pia matters with the anechoic subarachnoid matter in between the two.  The spinal cord sagittal diameter at the cervical and lumbar regions was greater than that of the thoracic region, and the cord was tapered at the mid-lumbar region forming the conus medullaris. It was difficult to visualize the spinal cord after 30 days of age. In conclusion, ultrasonographic imaging of the canine neonatal spinal cord varies with age till 30 days old.

Key words: Dog, Spinal canal, Spinal cord, Ultrasound