Lou is a beagle and the canine protagonist of Cats & Dogs.

The inexperienced Lou is picked by young Scott Brody's mother as a pet a month after the family's previous dog, Buddy, is catnapped. Once esconced at the Brody house, he learns that he's expected to help protect his master and his family from the evil Mr. Tinkles. Butch served as his mentor and sidekick.