Diagnosis and Treatment of a Cervical Vertebral Fracture in a Sulcata Tortoise (Centrochelys sulcata)
A 17-yr-old, 22.2-kg, intact female sulcata tortoise (Centrochelys sulcata) was presented for evaluation of a suspected intestinal obstruction and a 2-month history of hind-limb weakness, anorexia, lack of defecation, and decreased urine production. Clinical signs included generalized subcutaneous edema, pelvic limb paresis, decreased vent tone, and ataxia. Computed tomography (CT) identified findings consistent with a chronic compression fracture of the eighth cervical vertebrae with severe extradural compression of the spinal cord and near-complete obliteration of the vertebral canal. The tortoise was medically managed in the hospital for 13 days and discharged with analgesic and antibiotic medications. Over the following weeks, the tortoise regained an ability to defecate and urinate, and the tortoise's motor deficits mildly improved. A recheck contrast CT at 39 wk postdischarge was consistent with remodeling of the chronic compression fracture and mildly improved extradural compression of the spinal cord. Approximately 2 yr after the initial presentation, the motor limb deficits were still present. Thirty-three months after initial presentation, the tortoise presented obtunded and with anasarca. The tortoise was euthanized, and the necropsy revealed bilateral demyelination with moderate axonal loss, astrocyte reactivity, and moderate dural fibrosis in the spinal cord, consistent with chronic compression at the level of C8. This report illustrates an unusual presentation of a chronic cervical vertebral fracture and spinal cord compression that was diagnosed and monitored via CT, the treatment and recovery of most of the initial clinical signs and persistent motor limb deficits, as well as the postmortem spinal cord histologic findings.Abstract
Photograph of a 17-yr-old sulcata tortoise (Centrochelys sulcata) 2 days after initial presentation. The tortoise was able to support its weight on its thoracic limbs, but the pelvic limbs were extended caudally. The caudal half of the tortoise is angled downwards, as the weight of the tortoise was not supported by the pelvic limbs. Subcutaneous edema can be seen in the cranial inguinal fossae. An esophagostomy tube can be seen secured to the tortoise's carapace.
Contrast enhanced computed tomography images of a 17-yr-old female sulcata tortoise. The location of selected transverse images (A and B) is demarcated by a corresponding reference line on the sagittal plane reconstruction of the tortoise. A compression fracture of the mid- to caudal region of the eighth cervical vertebra is present, indicated by a white arrow. The fracture margins are ill-defined, blunted, and mildly sclerotic. The caudal fracture segment is dorsally displaced and lytic in appearance. The C8 vertebral body is much shorter than the adjacent C7 vertebral body. There are comminuted fracture fragments of the vertebral body, and some of the fracture fragments are displaced dorsally causing near complete stenosis of the vertebral canal.
Contrast enhanced computed tomography images of a 17-yr-old female sulcata tortoise 39 wk after initial presentation. The location of selected transverse images (A and B) is demarcated by a corresponding reference line on the sagittal plane reconstruction of the tortoise. A compression fracture of the mid to caudal region of the eighth cervical vertebra is present, indicated by a white arrow. The lytic portion of the caudal aspect of the fractured vertebral body is mildly remodeled, as the fracture margins are rounded and some of the fracture fragments have resorbed. The fracture fragments have partially resorbed, resulting in a mild improvement in the stenosis of the vertebral canal.
Histologic lesions at the time of necropsy of the cervical spinal cord at the level of the eighth cervical vertebra attested of chronic cervical spinal cord compression within the fasciculi gracile. In these images, dorsal is oriented toward the top of the images. The insert in A (× 40 magnification) indicates the location of B–E (× 200 magnification, hematoxylin and eosin, A and B). Myelin sheaths are lost with replacement by gitter cells (demyelination), and there is asymmetric loss of axons, as attested by the loss of, respectively, Luxol Fast Blue (C) and Bielschowsky's silver (D) stains within the corresponding areas. (E) Glial fibrillar acidic protein (GFAP) immunohistochemistry highlighted increased numbers of reactive astrocytes within the affected areas.
