What is your diagnosis? L-2-Hydroxyglutaric aciduria in a 7 month old Staffordshire Bull Terrier

A 7-month-old 18-kg sexually intact male Staffordshire Bull Terrier was referred to the Neurology Service for investigation of left thoracic limb lameness, episodes of thoracolumbar kyphosis, and pelvic limb ataxia. The onset of clinical signs was reported as 10 weeks prior to referral. The episodes of kyphosis and gait abnormalities appeared to follow increased activity or excitement. During these episodes, the patient was perceived to be painful. Findings on general physical examination were unremarkable. Neurologic examination revealed mild
thoracolumbar kyphosis and mild proprioceptive ataxia of the pelvic limbs. The remaining findings on neurologic examination were within reference limits. Neuroanatomical localization was consistent with an abnormality of the forebrain, C6-T2 spinal cord segments, or both and potential abnormalities of the peripheral nerves or muscles. Results of a CBC and serum biochemical analyses were within reference limits.