Your link with your companion creature allows you to share with it any healing magic that's cast upon you.

Prerequisite(s): Ability to acquire an animal companion, eidolon, familiar, or special mount.

Benefit: When you and your companion creature have this feat, your companion creature is adjacent to you or sharing your square, and you receive the benefit of a healing spell (whether from yourself or another source), you can divide the hit points healed evenly between yourself and your companion creature.