Segmental hypoplasia of the spinal cord and syringomyelia in a calf

Abstract

Congenital malformations are functional and structural changes in organ systems, tissues, or organs that may develop during the embryonic or fetal phase. Spinal cord malformations, such as segmental hypoplasia of the spinal cord (SHSC) and syringomyelia, are rare in bovines. A Girolando calf from Valença, Rio de Janeiro, was admitted to the Veterinary Hospital of Universidade Federal Rural do Rio de Janeiro because of motor incoordination. Clinical evaluation revealed a 5-cm depression area in the spine at the dorsal line of the thoracic region. Neurological examination revealed reduced proprioception, pelvic limb extension with increased nociceptive activity, and reduced anal reflex. In radiographic examination, the body of the T11 vertebra had a trapezoidal wedge shape with ventral hemivertebra, probable agenesis or hypoplasia of the T11-T12 spinous processes, and fusion of the T9-T10 spinous processes. Myelography revealed extradural spinal compression caused by vertebral malformations. Necropsy showed no spinous processes (T11-T12), cranial stenosis in the medullary canal (T11-T13), and 1-3-mm pores in the white matter of the thoracic spinal cord (T8-T11). Microscopy revealed cystic dilatations in the white matter (T9-T11), cystic areas of varying sizes (T8-T9), and moderate reduction in the gray matter around the central canal of the medulla (T11-T13). Here, we reported the clinical and pathological findings of SHSC and syringomyelia in a Girolando calf. The features should be differentiated from other spinal cord syndromes. Congenital malformations are of economic importance, and their etiology and diagnosis are fundamental to disease control and progenitor-selection programs.