I have dog sat for up to five dogs - they were Black Labs and were delightful they had a very secure fenced in back yard and love to play with their toys and chase after balls. They owners preferred them to stay in the back yard (over an acre of fenced in area to be exercised in. I have also provided care for two elderly yellow labs that just wanted someone to lean on. They weren't interested in walking any more but just wanted some human contact. I also have dog sat for a very active smaller terrier mix who loves to walk. Overall it is important to adapt to whatever the owners and the individual dogs needs are. Dogs are individuals and need their particular preferences met.