In the scene where the actors rollerblade in the Venice Boardwalk and they pass a woman walking with a dog on a leash, all the dogs in the background were professional dogs brought to the set by their trainers. Prior to shooting, all three dogs were placed on leash and handed to extras. The dogs were all well behaved and the area the dogs were walked in was taped off from the general public. On action, the background actors walked the dogs from A to B.
In the scene where the actor sees two policemen on horseback in front of a building, prior to filming the trainers brought the horses to the set. The horses wore rubber easy boots to prevent slipping on the concrete. The mounted policemen were experienced horsemen. The path that the horses were working on was clear of equipment, clean, and was a clear path. The crew and talent were instructed not to interact with the horses. The hummer that was used in the scene was driven at a very slow speed and kept a safe distance from the horses.
In the scene where the actress sits on a bus stop and sees a woman with a dog across the street, prior to shooting the background actor and her dog brought the dog to her mark. On action, the actor played fetch with her dog on a grassy area. All vehicles were a safe distance from the dog. Between takes, the owners would stop what they were doing and have the dogs rest wherever they were.