Progressive nonambulatory tetraparesis and cerebellar signs in a 6-year-old spayed female Shiba Inu dog with normal brain MRI.

A 6-year-old spayed female Shiba Inu dog was evaluated because of a 2-week history of progressive paraparesis that advanced to nonambulatory tetraparesis with cerebellar signs. The dog was fed a nutritionally unbalanced, commercial, freeze-dried, raw, fish-based diet. Thoracolumbar and brain MRI revealed no abnormalities, and CSF analysis showed albuminocytologic dissociation. Based on dietary history, clinical progression, and response to therapy, a presumptive diagnosis of thiamine deficiency was made. Treatment consisted of dietary modification and oral thiamine (vitamin B1) supplementation, resulting in near-complete neurologic recovery. This report describes an atypical presentation of suspected thiamine deficiency in a dog with normal brain MRI and highlights the importance of dietary assessment in cases of progressive neurologic disease. Key clinical message: This case highlights the critical importance of obtaining a thorough dietary history. In this dog, thiamine deficiency was suspected based primarily on consumption of a raw-fish diet that appeared not to be nutritionally complete and balanced, and confirmed retrospectively following a rapid clinical response to dietary correction and thiamine (vitamin B1) supplementation. Recognition of diet-associated neurologic disease is particularly relevant to general-practitioner veterinarians, as timely identification and treatment through diet modification can result in substantial neurologic recovery and may prevent death or euthanasia due to a treatable condition.