Originally posted by GunsForBucks:

Maybe a grenade you could lob at them.
Wouldn't want it too OP though... maybe heal max hit points over 5min and have a 1200 second cool down?

A notch up from the healing "arrow" I like it. A bit grandiose though.

Perhaps a variant of iron nail. Maybe "rusty iron nails", you'd sprinkle these at the feet of your pets and they could heal up that way.