Know to be man's best friends, cats and dogs have engaged in a fierce and merciless battle. Now, Mr. Tinkles, a ruthless cat, is plotting intensively to achieve nothing less than world domination. His main target is Professor Brody. The professor is working on a medication that will rid people of their dog hair allergies. Mr. Tinkles strives to get to the substance and have it analyzed. He then means to have it altered so that all humans of the world...

A look at the top-secret, high-tech espionage war going on between cats and dogs, which their humans are blissfully unaware of. The film follows Mr. Tinkle's (a cat) plan to destroy a new vaccine, that if developed, would eliminate all human allergies to dogs, and allow cats to rule the world. Lou, a beagle puppy accidentally becomes the dog-agent assigned to stop the cat plan.