When his mother brings home a guinea pig instead of the dog he has always wanted, fifth-grader Rufus is not happy--until the rodent starts acting exactly like a dog.

"The laughs continue when Fido, the guinea pig that thinks she's a dog, has a pup that thinks she's a squirrel. A sequel to Guinea Dog"-- When his classmates learn about Fido, the guinea pig that acts like a dog, they all want a piece of Rufus, her owner. But Rufus hates the attention, and decides to make Fido learn how to be an actual guinea pig. But when she goes missing, he feels terrible. Was she lost, or did she run away, because he no longer...