The show is about two girls, ditzy blonde Sandy (voiced by Jackie Joseph) and smart, sensible, bespectacled brunette Monica (voiced by Julie Bennett), living with their uncle, Dudley (voiced by Frank Nelson). Sandy bought a cute pup named Dinky (voiced by Frank Welker) who suddenly grew the size of a horse. She is now stuck dragging Monica into always finding work and different ways to repair the damages Dinky causes at their poor uncle’s expense. Sure enough, however, Dinky always seems to fix things in an unexpected way and is forgiven, much to uncle Dudley’s dislike.
In the second portion of the series, Dudley takes the nieces for a world tour on a rented leisure boat, giving Dinky a chance to cause mishap on the different continents for more adventures.