It's a slightly different story for wolves who wish to become a healer. After ranking up to subordinate (or otherwise known a novice healer), they will do basic battle and hunting training like every other wolf, but will also undergo the learning of herbs. When the time comes to receive an Official Rank, they will rank up to healer rather than a hunter, warrior or scout like all the other subordinates. There are two Healers in each pack.
From novice healer to healer:
Have been active for at least a month
Have been to one full moon gathering
Have gone on two patrols for herb collecting or border marking
After you have completed the following, message your pack alpha and they will create a ceremony