What is central canal dilatation?
The central canal is the narrow cerebrospinal fluid-filled space that runs longitudinally through the length of the entire spinal cord. It is contiguous with the ventricular system of the brain and is the adult remnant of the neural tube. Under normal circumstances it is only just appreciable on a MRI. If it is abnormally dilated then this will be recorded in MRI reports however small central canal dilation (less than 2 millimeters) does not appear to cause a problem to the individual dog. Nevertheless it is part of the spectrum of CM/SM and some young dogs with central canal dilatation have subsequently progressed to syringomyelia and some dogs with central canal dilation have produced offspring with syringomyelia (Rusbridge et all 2009). Central canal dilation may be difficult to appreciate especially on low tesla MRI machine therefore MRI screening should include images in at least 2 orientations (sagittal and transverse).
