Behind the everyday life of American suburbia, dogs run a global network of secret agents.
Mr Tinkles (Sean Hayes), a white Persian despot cat, is scheming to interfere in Professor Brody's (Jeff Goldblum) work on a cure for dog allergies.
After the cat-napping of the Brodys' dog, the worldwide canine organisation arranges for a secret agent pup to be infiltrated into the family, but Mrs Brody (Elizabeth Perkins) picks Lou (Tobey Maguire), an untrained beagle puppy, instead.
Lou soon finds out that he is not just a family pet. Butch (Alec Baldwin), a top dog who works for the canine equivalent of the CIA, assigns Lou to guard his master.
What follows is a war between cats and dogs, with the Brody household the front line.
Mr Tinkles sends in feline ninja fighters and a Russian agent to attack Lou, stop Brody's research and, in the grander scheme of things, conquer the world.
What follows are some hilarious scenes of dogs and cats flying through the air, flinging weapons at each other and enacting Crouching Tiger and Matrix-style martial arts moves.
Combining real animals, realistic puppets and computer-generated effects, all the animals are very convincing. Special effects even enable the dogs and cats to mouth words like Babe the pig did.
The wild action and special effects also allow Ninja cats in night-vision goggles to parachute down and attack the enemy with kung-fu punches.
Baldwin and Maguire are fairly easy to identify behind the ears and whiskers, and if you listen carefully you'll be able to recognise the voices of Susan Sarandon, Michael Clarke Duncan, Joe Pantoliano and Charlton Heston.
Cats & Dogs will test where your loyalties lie. Whether you are a feline fanatic or a canine comrade, watch this fun, action-packed film and see if the dogs can save humanity from a total cat-astrophe.