Radiographic and <scp>MRI</scp> findings of spina bifida of the <scp>T3</scp> ‐ <scp>T5</scp> vertebrae in a dog

An 8-year-old male Australian shepherd was presented with a 1-month history of left thoracic limb lameness. An orthopaedic evaluation was unremarkable. Neurological examination demonstrated mild ambulatory tetraparesis, pelvic limb general proprioceptive ataxia, mild proprioceptive deficits on the left pelvic limb, decreased withdrawal reflex in the left thoracic limb and mild cervical hyperesthesia. Neurolocalisation was C6-T2 spinal cord segments with left lateralisation. The main differentials were intervertebral disc herniation, caudal cervical spondylomyelopathy and neoplasia. MRI of the cervicothoracic spine revealed a neoplasia of the left T1 spinal nerve root with extradural and intradural-extramedullary localisation and possible intramedullary invasion. Radiographs and MRI of the cervicothoracic spine revealed bifid spinous processes of the third, fourth and fifth thoracic vertebrae as incidental finding (Fig 1). Spina bifida is a congenital malformation well documented in dogs, resulting from the failure of the closure of the dorsal aspect of the vertebral arch during embryogenesis. Usually, chondrodystrophic dogs are the most affected and the most typical site is the lumbosacral region, although other vertebral column regions have been reported. Our case described spina bifida in three consecutive vertebrae, in vertebrae usually not affected by this condition, in a breed not predisposed. Moreover, in the typical presentation, the affected vertebra is best seen on the ventrodorsal view because the two spinous processes are side by side and overlap on the lateral view. In our case, they were staggered, giving an unusual imaging appearance of this abnormality on the lateral view. C. Remelli: Investigation; writing – original draft; writing – review and editing. T. Davini: Investigation; writing - review and editing. M. Bernardini: Conceptualization; investigation; writing - review and editing; supervision.