History: The dog was evaluated because of abnormal gait and weakness in the pelvic limbs. The owners reported that the dog was falling occasionally, had difficulty climbing stairs, and was knuckling and scuffing the feet of both pelvic limbs. Signs were worse on the dog's left side, according to the owners. The ataxia and paresis had progressed slowly over the preceding 6 months. A diagnosis of hip dysplasia had been made previously by the referring veterinarian, who also surgically removed a subcutaneous lipoma from the left shoulder area 6 months