You need a dog also - they will be friends and good companions for their human owners. (I have three, and when we walk and pass walkers out by themselves, point out that they really should have a dog as company. Just because.)

Back in 2011 a gorgeous chocolate lab wandered into my yard, and I snapped a leash on him and walked up the street to find out who owned him. No way I was going to let him keep wandering. After a little while a minivan pulled up and Susie (who became a fast friend) greeted me and her dog Zeke, a frequent escapee from her yard. We talked, and started walking our dogs together in the mornings. My pitbull Cinnamon loved him, and my blue heeler mix did not. So we walked side by side with Cinnamon and Zeke next to each other and Poppy on my other side. She would growl if he got close.

After about four months, I noticed that Poppy wasn't growling at him, and even, when no one was looking, sometimes she'd offer him a little kiss. So we started meeting at my house one morning a week for tea and muffins and let all three dogs loose in the huge back yard to dash around. Zeke always broke out of her yard to go to yards with other dogs, and as Susie was having to drive her ill husband to Houston for chemo, I convinced her to leave him with me for those few days, not make him stay in a car all of the time or alone at the house. They all enjoyed the visits.

Cinnamon and Poppy are gone, and Susie was badly injured in 2012 and ended up giving Zeke to me because with a head injury she wasn't as stable as before. Susie is much better, Zeke still lives with me at the ripe old age of 14, and his companions are Pepper, about 6 years old blue heeler and 2-year-old Cookie, the pit/boxer mix. Cookie adores him.

Cinnamon was an injured stray who stayed, Poppy came from the Humane Society to be her companion. After each girl died I waited a few months then headed to the city animal shelter and picked the two I have now. It's a process, picking a dog - paying attention to them paying attention to you. I think it is a mutual process (or, it should be - connecting before you leave the building is always a good idea.)

Good luck to your friends in their dog selection, and how ever many you bring home, enjoy all of those walks together!