In a study on dogs quoted today in the Wall Street Journal, a detailed scientific study was done on whether the perceived benefits of dogs are truly valid. Dr. Lauren Powell, now at the University of Pennsylvania did a study with several control groups about whether dogs really "reduce our loneliness and make us feel happier." In addition to finding that loneliness and depression decreased substantially, "the presence of dogs actually increased the flow of oxytocin, a hormone that decreased our heart rate and fosters feelings of well-being and relaxation." Physically, there were benefits from the extra walking and just being outside while emotionally, we who have dogs are all better off and make more social connections while we're out walking.
Just look at how a dog lives in the presence and finds joy in small things.