I tried this today and got the message that 'NPCs cannot be healed'. I could heal my companion with spells and with a rod of healing. I did not try a potion.

Is this a bug, or by design? Maybe the companions can be treated as non-NPCs for this purpose?

tedgoat I tried this today and got the message that 'NPCs cannot be healed'. I could heal my companion with spells and with a rod of healing. I did not try a potion.

Is this a bug, or by design? Maybe the companions can be treated as non-NPCs for this purpose?

Fixed.