Juno MacGuff is sixteen years-old who after a one-time sexual encounter with her best friend Paulie, learns that she's pregnant. Juno and Paulie like each other, but not enough to start a family, complete with a child. Paulie leaves all the decisions about the baby to Juno. Initially she decides to have an abortion, but can't go through with it. So she decides to have the baby and give it up for adoption. The next step is to find prospective parents...

Rex is the world's most famous, and Hollywood's most pampered, pooch. He gets lost and is reluctantly adopted by a young boy. His father, the fire chief of a rundown station, agrees to the adoption only if his defiant son takes care of the dog. Little do they realize Rex will not only bring them closer, but also bring some much-needed faith back to the fire station.

Adopted by the Newton household's three children, an adorable little St. Bernard puppy grows into 185 pounds of disaster-prone trouble; There's trouble in the heir when Beethoven becomes the proud father of four pups, each one an adorable but mischievous bundle of joy; When two bumbling thieves threaten the safety of his family on vacation, Beethoven sets out to put a bit on the bad guys.