NOTE: This spoiler was sent in by: Mli0922

The movie starts out with the FBI searching for drugs at a drug dealer garage, but the FBI agents could not find any. So then they brings out Agent 11 (the dog) out to sniff, and of course, the dog finds the drug. The dealer tries to make a run, but Agent 11 ending up biting off one of his testicles (the movie doesn't tell you it, but it certainly implies it).

The next scene shows mailman Gordon (David Arquette) delivering mail in a doggy neighborhood, and shows how he fights off the dogs using meat, watergun, and other sorts of weapon. Gordon is in love with his neighbor (I can't remember her name), who has a son. Gordon gives the son a dog puppet (it'll be important later on). We can obviously see that Gordon and his roommate are pigs. The mom has to go on a business trip for a day, but the baby-sitter couldn't show up at the last minute, so Gordon takes over. Gordon changes the son from a good boy, to a child psycho.

One day at the FBI dog training camp, two hitmen tries to kill Agent 11. Agent 11's partner (Michael Clark Duncan) is being forced to send Agent 11 to a dog camp up in Alaska but the tags on Agent 11 were switched in the last minute, and a small dog was send to Alaska instead of Agent 11. The two hitmen once again try to shoot Agent 11 while he was in his cage in the van, but agent 11 escapes and gets into Gordon's mail van. One thing led to another the son convinces Gordon to keep the dog. and they name Agent 11 Spot. At the same time, the mom (which I really felt sorry for) is stuck at the airport. and cannot get back.

Gordon and the son try to play with Spot, but Spot is trained to not play, so they think that Spot is retarded. Finally Spot learns to play, and the FBI finds out how Spot was lost, and that Spot is Agent 11. Meanwhile on the other side, the mom's bus was trapped in a dirt pod. After the bus threw some wet dirt on her, the bus falls into the mountain and explodes. The mom loses her cell phone when a car wouldn't stop to take her on. She ends up sharing the back of a truck with a zebra.

After the hitmen tries extremely hard to kill the dog and fails again and again, the boss comes in. The boss captures Gordon, Spot's partner, the kid, and the dog. After a long fight, Agent 11 bites off the other testicle of the guy.

The movie ends with the mom finally getting home looking like a witch on a biker's motorcycle, completely furious with Gordon. Spot decides to stay with Gordon instead of going back to the FBI. In the end, the mother forgives Gordon and decides to start a new life with Gordon, the kid, and Spot.