Trivia

According to George Lopez, Papi, the chihuahua he voices in the movie, was one day away from being put down before he was rescued for the movie.

For the scene in the dog pound, all the dogs were either locally owned or trained production dogs. They were cued to bark and walk to the front of their air-conditioned and comfortable kennels. When Diablo runs down the street chasing Chloe's scent, hot dogs were rubbed on the ground to get the dog to sniff. When Papi (voice of George Lopez) is seen digging holes in the yard, the holes were pre-dug and partly filled with loose potter's soil and the dog was cued to dig. When Rafa (voice of Eddie Sotelo) and another dog rest in sewer pipes, the dogs were placed in "down" positions and told to stay inside the concrete pipes, which were solidly secured. For the scene in which Sam (Manolo Cardona) and Rachel (Piper Perabo) wash the two dogs, the shampoo was dog-safe.

When awakened suddenly, Rachel appears to whack Chloe across the room. The dog was cued to speak, then the actress, using the support of a blanket, gently tossed the dog onto some padding placed next to the bed. The well-rehearsed dog landed on her feet and was rewarded with food.

For scenes in which dogs bark, whine, growl or snarl, a trainer cued them to "speak" and used various training tools (toys, treats) to achieve certain reactions. When the dogs' mouths move as if they are speaking, this was a special effect digitally added after filming. Whenever Chloe is being carried in the mouth of Delgado (voice of Andy Garcia) or El Diablo (voice of Edward James Olmos), a fake prop dog was used in combination with computer-generated imagery.

Aunt Viv (Jamie Lee Curtis) arrives at the spa carrying Chloe in her handbag. The handbag had a special reinforced handle and a Velcro closure. In the scenes with the dogs in the spa, dog-safe shampoo was used, the mud bath was special spa mud mixed with gelatin, the curling iron was unplugged, and the blow dryer blew only cool air. The dogs being groomed were held by well-rehearsed actors or trainers standing in for actors. The dogs on treadmills were attended to by trainers and given rest between takes.