"A humorous story about an unusual pet. Rufus has but one wish - a dog. His stay-at-home Dad does not agree. His list of reasons not to get a dog extends over two pages. Rufus's sympathetic mom brings home a guinea pig, which Rufus has expressly said he does not want. To his surprise, though, the guinea pig (which he sullenly names Fido) behaves like a dog! She obeys every command Rufus gives her, plays tug-o'-war, and even chews shoes. His best friend wishes she were his when, during a Frisbee game, out of nowhere, she retrieves the disc and brings it to Rufus..... Jennings provides no explanation as to why Fido acts like a dog, asking readers to accept the absurdity along with Rufus. The school characters are fairly one dimensional, but the undeniably funny plot moves along, and readers into beginning chapter books should enjoy this wry story of wish fulfillment." (Kirkus Reviews)

"Jennings' salute to kids who get less (and more) than they ask for offers a unique and hilarious take on boy-dog bonding. Fifth-grader Rufus begs for a dog, but because Dad says no (in an enumerated list), Mom brings home a guinea pig. Rufus is disappointed, and Dad is annoyed, but because the pet shop has vanished, they are stuck with a rodent that barks, fetches sticks, whines, and licks faces. Rufus is both embarrassed (what will his friends think?) and charmed by Fido's doglike behaviors; the scale finally tips in the pig's direction when he executes a perfect, Lassie-like rescue of his master.... Short, manageable chapters; a breezy, conversational style; and identifiable characters (the bully, the show-off, the obsessive stay-at-home dad) make this a good choice for readers making the transition to chapter books." (Booklist)

"Fifth-grader Rufus's only wish is to get a dog, but his work-at-home dad objects. He lists numerous reasons, including that dogs lick people’s faces, chase cars, and eat dead things. Rufus's mom brings home a guinea pig instead in an attempt to fulfill her son's desire for a pet. To his surprise, the guinea pig, which he names Fido, acts like a dog. She obeys his commands and chews his dad's shoes. When Rufus' family decides to return the animal to the pet store, a classmate is willing to buy her to replace her hamster. But Rufus begins to have second thoughts about relinquishing the guinea pig. Although no explanation is given for why Fido behaves like a dog, children will have no problem accepting the absurdity of the situation. Early chapter-book readers will enjoy this humorous tale." (School Library Journal)