can u produce (extract) endorphin from living animal?

yes you can.. provided the endorphin was produced surrounded by a large ample amount, the problem is to make it worth while you'd probably enjoy to kill the animal within order to receive as much as you can since a lot is lost during the purification
I don`t know in small amounts but that'd probably entail neurosurgery to do so if i'm not mistaken. i'm an animal carer not a neurosurgeon