Lateral angiogram (left) of the common pattern of the carotid trifurcation and the internal carotid artery of a donkey. 1 common carotid artery; 2 external carotid artery; 3 internal carotid artery; 4 occipital artery; 5 cranial branch of occipital artery; 6 caudal branch of occipital artery; 7 linguofacial trunk