My best friend loves animals, but particularly dogs so she volunteers her time and walks them once a week. It benefits her because she is getting exercise by walking several miles and the dog gets much needed time away from the shelter and one on one attention.
That is awesome that she volunteers to do that and gets benefits from it as well. I was a rescue, so it's great when people take an interest.
I truly believe that volunteers receive just as much back from the pets as the pets receive from them.
If we label an animal as friend for people, this can be dog. Spending time with them is lovely.