I think dogs (like most pets) are here to teach us unconditional love. It is just my theory, but it seems to hold true. when I love an animal, I love them with all my heart. Which might explain why losing my cat to cancer hurt so deeply.
Anyway, I had a black lab when I was a kid and she went just about everywhere with me. One day "Blue" (her name), on my way to a neighboring town, jumped out of the car at the river and took off. We could not find her so we went on to my grandmothers as that was our destination. I was very upset and thought I would never see my dog again as she had never been to my grandmothers house and it was about 15 miles from the river.
The next day when we arrived back hoe 36 miles away, we got a call from my grandmother that Blue had showed up at her house.I was elated. And when the day came that Blue died I cried for a week, practically non-stop. I loved her the same way she loved me, unconditionally. And I have been grateful for her all these many years later, Still remember her with love.