Was largely filmed in the southern area of Pasadena, however at the beginning of the film, when Harvey and Vernon are chasing down the dogs, this was filmed on the back-lot at Universal.
So incensed were the American Veterinary Association about the depiction of a vet as leader of a dog-napping ring, they fired off a letter of protest to Jack Valenti, head of the Motion Picture Association of America.
In the scene after Beethoven "attacks" the vet, Dad goes into the backyard and gets Beethoven to take him to the vet's office, the dog's neck and snout are mysteriously clean even though only moments earlier they were smeared with fake blood.
Devonia Pest: [after Alice picks up the kids and heads to the car]
She must have snuck out while I was watching Ted and Ryce. It was hot out, so I guess she wanted to take a little swim.