NAVLE（北美执业兽医考题）Day 544

Q1:A four-year-old Rat Terrier is presented with a three days history of progressive stumbling and falling. Physical exam reveals a right head tilt, left sided hypermetria, generalized ataxia and vertical nystagmus. Which one of the following choices is at the top of the differential list?一只4岁大的梗犬3天来出现进行性的蹒跚和跌倒。体格检查提示头颈右侧歪斜，左侧运动范围增大，广泛性共济失调以及垂直性眼球震颤。以下哪个选项在你的鉴别诊断列表最上方？Find out the answer by clicking on one of the listed choices. Good luck!点击列出的选项找出答案，祝大家好运