A third generation police K9, and a civilian underdog built for speed are among the pooches who face off in a competition that comes right down to the wire. Who will get the last woof?

A fur missile, a veteran K-9 named Murphy and a small civilian underdog compete.

Two civilian underdogs take on the professional pooches in an epic clash of K-9s, as a brash boxer and a peppy pit bull attempt to be leader of the pack

The youngest dog in the competition sets a fur-ious pace; the more experienced dogs must take matters into their own paws or a youngster will bring home all the biscuits.

Among the K9 combatants are a dog who once took down a crossbow-wielding creep, a pooch whose trainer is allergic to him, and a team with inspiration on their side. Who will emerge lick-torious?

It's raining cats and dogs, but the K-9 combatants show their gladiatorial spirit, battling through bad weather and tricky tunnels right down to the final seconds.

With some of the most decorated doggies ever to set paw on the K-9 combine, records may be broken.

The lineup raises burning questions such as if old can defeat young and if skill can beat experience.

A Doggle-wearing K-9 faces some tough competition including a Connecticut K-9 who's ready to declare war and cancer-surviving civilian underdog named Bruce.

Six winning K-9s and one champion underdog battle it out for $25,000 and the bragging rights for the ultimate title of "America's Top Dog."