Space Dogs — Justin Ball; Evan Croker

It all begins with Laika, the first dog in space. Launched into orbit by the Soviet Union, Laika's craft is accidentally sucked through a wormhole and onto the Planet Gersbach, inhabited by highly intelligent but very tiny people.
When a mysterious disturbance of gravity (D.O.G.) threatens to destroy Gersbach, Commanders Belka and Strelka are just the men to seek and destroy the source of D.O.G. Their vehicle: A highly sophisticated craft that looks exactly like a terrier. Blending in with the locals on earth should be no problem.
And with the help of the Buckleys, a lovable Earth family with problems of their own, the mission to save their planet may still prevail.