Segmental spinal cord hypoplasia in a Holstein Friesian calf

Tethered spinal cord related to caudal spinal dysraphism in a tailless Holstein calf

A rare dysraphic caudal spinal anomaly, or caudal agenesis, comprising a tethered spinal cord, was found in a tailless Holstein calf that presented ataxia and paresis with analgesia of the hind limbs. The gently and slimly tapered conus medullaris was poorly formed between S2 and S3 which indicated that it was lying more caudally. The caudal end of the filum terminale adhered to the inner periosteum of the vertebral arch at S4, which is compatible with tethering of the spinal cord. The dysraphic changes from the secondary neurulation error and the longitudinal deranged cord morphology that may have been caused by the caudad traction due to tethering were confirmed. This represents the first bovine case with definitive morphological confirmation.

Segmental spinal dysgenesis with caudal agenesis in a Holstein calf

A rare complex dysraphic malformation, comprising segmental spinal dysgenesis with caudal agenesis, was found in a Holstein calf that was unable to stand and was slightly short at the lumbosacral spine with taillessness. The thoracolumbar and sacrococcygeal regions of the midline axial segments showed severe deformities. In the spinal cord, the thoracolumbar region showed severe constriction with myelodysplastic changes, and the sacrococcygeal region showed dorsoventral separation with connection to a neural mass. In the spine, vertebral anomalies according to the degree of the segmentation error were confirmed. The cervical and thoracic segments also showed milder dysraphic changes. These changes suggest a multisegmental causal insult impairing the early embryonic notochord. This represents the first bovine case definitively confirmed morphologically.