"Jennings picks up where Guinea Dog (2010) left off in this playful, quick-paced tale that touches on some common dilemmas for middle graders. As the story opens, Rufus once again feels ambivalent about the doglike behavior of Fido, his guinea pig. Rufus' friend Murph has been exaggerating Fido’s role in saving Rufus' life when he broke his foot 'crossing a raging river filled with snapping turtles.' (It was really a slow-moving creek devoid of snapping turtles.) Now, Rufus' classmates are showering him with unwanted attention. They all want guinea dogs, especially his nemesis, Dmitri, who will not take no for an answer. To make matters worse, eccentric Lurena - a girl! - keeps coming to Rufus' rescue. There's only one solution: Rufus needs to un-train Fido - and help her lose the extra pounds she put on while Rufus was laid up. But Fido runs away! Short chapters and a slightly larger-than-usual font make this an easy read. Rufus is a snappy narrator, and his fumbling observations about his parents, himself, his friends, and his situation are fresh and funny. Youngsters will relate as Rufus learns to say no, feel grateful for his friends (whether boy or girl), and make right his relationship with Fido, whose weight gain was for a very good reason. With the introduction of Fido's gifted progeny, Jennings leaves readers begging for another absurd adventure." (Kirkus Reviews)