Trivia

Although Jerry Lee is credited as playing himself in the opening credits, he was in fact played by multiple dogs during the shoot.

The primary dog was named Rando, a three-year-old German Shepherd. A two-year-long search was held to find the right dog for the role and over forty dogs were considered. Eventually, four young Shepherds were brought from West Germany and trained for three months with Karl Lewis Miller. While typical dogs can understand 10-15 commands, Rando was able to perform anywhere from 125 to 150 actions.

A separate dog that was used as a stand-in for some scenes was named Kondo, and was a real-life police dog with the Kansas City Police Department who was sadly killed in the line of duty in 1991, which has led to some confusion that "the dog from K-9" was killed while on duty.

Contrary to the claim made by Jim Belushi's character that his car is a classic 1965 Mustang, the only '65 mustang in the movie is the one at the end when they are driving to Vegas. Any others used in the movie are '66 models.

The waiter serving Dooley at the Hotel Del Coronado is played by Dan Castellaneta, the voice of Homer on the long running animated comedy "The Simpsons".

At the dinner party given by the gangster, there is a butler walking across a room behind a doorway. The butler is Michael John Robert Gill who was working with the catering staff hired for the film. After the filming, he actually served the food used in the scene to the cast and crew. Gill was not an actor but was actually a real English butler, and for seven years he was butler to British actor Laurence Harvey, prior to his death.

The game played by Dooley in his car is a Game & Watch from Nintendo. The game is called "Manhole", which was released in 1983.