Lateral angiogram of the left carotid arterial tree of a donkey shows variation from the common pattern of this structure. The left internal carotid artery (red open arrow) originates very caudal to the common carotid artery termination. 1 common carotid artery; 2 external carotid artery; 3 internal carotid artery; 4 occipital artery; 5 linguofacial trunk