NAVLE（北美执业兽医考题）Day 601

A 10 year male castrated German Shepherd dog presents for an acute onset of ptosis, drooping of the lip, and drooping of the cheek all on the left side. What nerve has been damaged？

一只10岁的雄性已绝育德国牧羊犬出现急性的左侧眼睑下垂，嘴唇下垂以及颊部下垂。提示哪个神经受到了损伤？