Crystal: Malachite, rose quartz, watermelon tourmaline, rhodochrosite or clear quartz
Energy: Love, kindness and affection
An open, balanced, aligned Heart Chakra will allow your dog to be loving and friendly, a pleasure to live with. This is the essence of a "Good Dog."
An under-active Heart chakra may cause your dog to be fearful, cold and keep you at a distance emotionally. These poor dogs may not have known human love during critical phases of their growth. Their trust in others has been lost and they shut their hearts down.
In my opinion, dogs cannot have an over-active Heart Chakra as they ARE love. They do not have it in them to play games with love or to twist or use others emotionally.