Before filming began, cast and crew members were instructed on the safety and handling of the animals, all of which were extremely well-trained and well-rehearsed. All streets were closed to traffic and all grounds were thoroughly inspected and contained no hazardous terrain.

Several Great Danes were alternated in the role of Marmaduke. The animals' "talking" mouths were added in post-production. The dogs and cats were rested and shaded between takes and given plenty of food, water and praise. All of the dogs and cats in scenes together were familiar with each other and accustomed to being together. Whenever dogs or cats barked, meowed or performed mild action, such as sitting, jumping, digging, walking or running (on- and off-leash), off-screen trainers used hand signals and verbal commands to achieve the action. The mild puppy-on-the-couch action was achieved in the same way. The dogs inside "purses" were rehearsed to sit or stay inside the prop handbags while secured to waist ties. For shots in which a paw is seen close up, the paw was usually a prop or animatronic.

All food and liquid given to the animals was deemed safe for animal consumption. Any object held in an animal's mouth was a lightweight prop that was not hazardous or breakable, and the Frisbee that hit an Afghan in the face was a foam prop, gently tossed. All costumes worn by the animals were custom-made for comfort. For the scene in which the dogs are in the rain, the rain was made with a warm-water rain machine, and the dogs were extremely well-rehearsed for these short (and limited) takes and dried off right afterward.

All bees in the film were computer-generated imagery (CGI).

Dog and Cat Action

Whenever the animals were filming in the "dog park," costumed and hidden trainers cued them to perform the rather mild action on the fake, enclosed set. For scenes in which Marmaduke knocks down a person, the person was a stunt double who fell in well-choreographed, exaggerated movements. One even did a flip in the absence of the dog and the footage was edited together.

The scene in which Carlos the cat is hit by a ball and knocked off a table involved a split-screen stunt with a very well-rehearsed cat filmed against a green screen. The trainer gently nudged the cat off the table and onto stunt pads below. Then a ball was thrown, knocking dishes off the table. These actions were then edited together.

The scene in which Carlos falls from a tree branch was filmed in separate shots. The well-rehearsed cat was placed upside down on a low branch and cued to let go — this well-choreographed fall was only a couple of feet above padded ground. The footage was edited to look like it was a higher fall.

In a couple of scenes, Marmaduke's ears perk up. This action was achieved using a monofilament line gently attached to the dog's ears and controlled by a crew member.

Scenes in which Marmaduke appears to be in a moving convertible were either filmed against a green screen in a stationary car or filmed on a trailer driven slowly a few feet, with the exception of a couple of scenes in which the car pulls up to a specific destination. For those scenes, either the well-rehearsed actor or a costumed trainer drove a few feet on a closed road while trainers cued the dog to stay. The dog was secured to the car seat with a leash and safety line and a trainer hid in the back seat holding the safety line. For scenes in which a car appears to drive near Marmaduke, a stunt driver kept the vehicle a safe distance from the dog.

The green-screen scene in which Marmaduke becomes stuck in a tiny dog door involved a fake dog-door frame placed around the dog's neck and held by trainers while the dog was cued to move back and forth, as if struggling. The rest of the door and walls were added in later.

For the shot of Marmaduke pulling a 3-year-old girl by his leash, a trainer actually walked the dog on the leash while the child actor walked behind with a second leash. The front leash and the trainer were removed in post-production. The Elizabethan collar was a prop that was rigged to fall off.

Carlos the cat sits on a recliner while Marmaduke sits on a couch next to him, and Marmaduke hits an "ejector" button, causing the cat to fly across the room. A CGI cat was used for this "launching" action (the mild couch-sitting action used a real cat cued by trainers).

After eating a hot grilled cheese sandwich, Marmaduke sticks his head in a sink full of soapy water. This scene used a combination of a live dog trained to run to the empty sink and put his head down and a prop stuffed dog. The sandwich prop was not actually hot. Later, for a scene in which Marmaduke runs out of a bathtub full of suds, the bathtub and bathroom floor were lined with mats for traction, the suds were from a special nonirritating dog soap and the dog was rinsed and dried after takes, which were limited. The part of this scene in which Phil (Lee Pace) grabs Marmaduke by his tail and is dragged through the house was a visual effects shot involving the dog running without the actor, and a shot of the actor with the tail added in post-production.

Scenes of the dogs and cats at the dog park or at a party (sometimes performing tricks and stunts) used trained behaviors cued by off-screen trainers. "Debris" or scenery in these shots was either nonhazardous material placed there ahead of time or created with green-screen technology. Dogs seen in the pool were water-loving dogs swimming in a warm-water, nonchlorinated pool with trainers scattered around the set. The dog seen jumping off a roof into the pool was cued to jump off a platform a few feet high in front of a green screen and into the arms of an awaiting trainer in the pool, with no other dogs in the way. Several shots were composited together in post-production.

The dog that drinks from the toilet and is hit in the head with the lid was a prop dog. For scenes in which the dogs dance, including break dancing to a video game and group dancing at the end of the film, most of this was an effect, except for establishing shots where trainers placed the dogs on their marks and cued a few movements or looks. The sparks flying after the "Dance Dance Revolution" game appears to short-circuit were added in post-production.

For the scene in which Marmaduke tries brushing his teeth, ultimately squirting toothpaste into Carlos the cat's face, was filmed in separate shots and also involved a special effects toothpaste tube. The tube was filled with cream cheese and attached to a small air hose. While the dog held the tube in his mouth, a crew member pumped air through it, causing the cream cheese to "launch" out. The cat's face was then manually covered with cream cheese (the launched cheese never hit the cat).

The scene in which Marmaduke fights Carlos at the dog park was filmed in separate green- screen and split-screen shots involving cued cat "swats" and fake dog paws lightly touching the rehearsed cat, who was kept just far enough from the dogs to not make contact. The part of the scene involving the cat flying through the air and sliding across the grass was filmed in separate shots. The cat was carefully dropped a few feet onto the ground and cued to jump off a garbage can. The action of the cat sliding across the grass was a digital effect combined with a shot of the live cat being pulled a few feet on a green-screen mat (that is, the mat moved; the cat did not).

For the dog surfing scenes, all the dogs were extremely well-trained and well-rehearsed. Shots of Marmaduke or Bosco surfing were achieved using a combination of methods. A dog sat on a surfboard and a trainer pulled the board toward the camera a short distance and cued the dog to look in certain directions. In addition, the dog playing Marmaduke was filmed on a surfboard prop on a platform (without water) in front of a green screen. These methods were combined with CGI to create Marmaduke's and Bosco's surfing scenes. The surfboard had a nonslip surface, and the ocean was actually a warm, shallow pool on an enclosed set, with the exception of a few establishing shots filmed in a shallow area of the ocean, where trainers held the board in place. Other dogs seen surfing were actual "surfing dogs" who had been highly trained to surf small waves. These dogs enjoyed this activity and have been surfing for years. Trainers were in the water with these dogs, and the waves were small and easy for the experienced dogs to ride to the beach. All surf dogs wore life jackets.

For the shot in which Marmaduke runs off, dragging a park bench behind him (because his leash is tied to it), this was an effect in which a special rig pulled the bench in front of a green screen. The bench was also rigged to fall apart as it moved. Marmaduke was filmed running without the bench behind him and the two elements were composited together in post-production. For the shot in which two small dogs were "surfing" on the moving park bench, they were actually cued to "stay" on a stationary bench in front of a green screen while a fan gently blew their fur to make it look like fast movement.

For the scene in which a large group of dogs is inside a Mini Cooper and then jumps out the windows, trainers placed them on their marks inside the stationary car and cued them to stay for a brief moment before calling them out, one by one, during this well-rehearsed scene.

The scene in which the dogs fall through a broken street into the sewer was filmed in separate shots on sewer and aqueduct sets with warm water piped in "currents." These dogs had been incredibly well-rehearsed for this scene, which involved green-screen elements and hidden trainers. For the shot in which Maisy appears to barely hang on to the edge of a slab of broken road, the dog who played Maisy was cued to crawl up a platform prop made to look like the road slab while a trainer wearing a green-screen suit held onto the dog's hips and pushed her up. The trainer was removed in post-production. For the shot in which Marmaduke pulls Maisy up to safety by holding her bandana in his mouth, the green-screen trainer held the dog playing Maisy so that the dog playing Marmaduke was never actually supporting her weight. For the shots of the dogs swimming through the sewer, the pool set was secured, with trainers all around. The dogs loved to swim, but they barely did any actual "swimming" — trainers hid in the water holding the dogs or having them swim a short distance from one trainer to another. Later in this scene, the fireman rescuer hangs from a rescue harness and catches Maisy, and Marmaduke tries to jump into the rescuer's arms but overshoots his jump and falls into the aqueduct. This scene was achieved using a green screen and special props. The fireman was a costumed trainer who hung from a rope rigged to the ceiling of the custom-built set. A second trainer wearing a green-screen suit (so he could be removed later) stood by the dogs on a platform and cued them to jump. The dogs only jumped a few feet, and the ground (which was only a short distance from the fireman) was lined with stunt pads. Water only flowed through the "tunnel" props during close-ups, not during the separate shots of the dogs jumping. This entire rescue scene was extremely well-rehearsed for many days. The tree was a prop secured to the set, and trainers either held Marmaduke in place or positioned his front paws to the tree stump for a brief moment until the actor held the dog in position.