在这部看狗在说话之旧金山历险记喜剧/爱情/家庭/冒险片中,一天，主人带着宠物狗运（迈克尔·J·福克斯 Michael J. Fox 配音）、莎莎（莎莉·菲尔德 Sally Field 配音）和幻影（拉尔夫·韦特Ralph Waite 配音）来到机场，他决定和他的小动物们前往洛杉矶，来一场精彩刺激的露营。然而，胆小的狗运误会了主人的用意，以为主人打算遗弃它，于是吓得一通乱窜不见了踪影，无奈之下，莎莎和幻影只得尾随其后，确保狗运的安全。
三只小动物就这样流落在了旧金山车水马龙的街头，它们要面对的，除了当地凶神恶煞的流浪狗外，还要提防野狗收容所派出的捕狗队对它们展开的围剿。最终，三只可爱的动物们凭借着它们的智慧，回到了主人的身旁。
Shadow, Sassy and Chance are back! It's been three years since their trek through the woods and over the mountains. Now the family lives in San Fransisco and they're taking a vacation in Canada. Only problem, the pets escape from the airport while being put in the cargo area of the plane. Now their family is in Canada and the pets are all alone in San Fransisco. They meet scruffy bully dogs and a gang of rebel dogs all abandoned and have started their own group. Also looking for them is a "Blood Red Van" driven by bumbling dog catchers. Also Chance meets a girl dog and it's love at first bite.
