Dog

Mary Randall recollects patrolling the Future War with dogs and detecting an Infiltrator in a poncho.

Dogs, a species of Earth animals (Family: Canidea; Genus: Canis), are well-known for their ability to detect Infiltrator units. They frequently start barking when an Infiltrator is in close proximity to them.

Ever since Skynet developed T-800 Infiltrators with living tissue over a metallic endoskeleton, the Resistance had experienced great difficulty identifying Infiltrator units. As a result, a significant number of Infiltrator units have been able to breach Resistance defenses and slaughter Resistance soldiers. However, the Resistance has found that trained "sniffer" dogs posted at checkpoints are effective at detecting this new threat.

Resistance members allow dogs to sniff hands, possibly because dogs are able to to smell the difference between a human and a Infiltrator.In addition, a dog can be trained to hear the sound of an Infiltrator's servos moving, which is too low to be detected by humans.

In order to counter the detection by a dog, Skynet develops the Hypersonic emitter to neutralize animals. In the NOW Comics timeline, Skynet developed the Big Bad Wolf as a counter measurement to dogs.

Known examples

• At the home of a wrong Sarah Connor, a very small breed of dog reacts to the T-800. The Terminator
• German Shepherds are stationed at the Resistance bunker checkpoint react to a Terminator. The Terminator
• A dog, another German Shepard, at the Tiki Motel reacts to the T-800. The Terminator
• Sarah Connor brings an Alsatian dog with her, presumably because of dogs' ability to detect the Terminators. The Terminator
• John Connor's dog, Max, reacts to a T-1000. Terminator 2: Judgment Day
• The stray dog pack at Mary Randall's safe house in Los Angeles reacts to C890.L. The Terminator: Tempest
• Mary Randall recollects patrolling the Future War with dogs and detecting a Terminator in a poncho. The Terminator: The Enemy Within issue #2
• The puppy Dieter von Rossbach wanted to give to John reacts to the T-800 they destroyed at Connor's safe house in Paraguay. T2: Infiltrator
• The dogs in Carlos' house react to Cameron. Terminator: The Sarah Connor Chronicles "Gnothi Seauton"
• A young Kyle Reese found a German Shepherd in a sewer where the dog barked at the presence of a Terminator coming in. Terminator Genisys
• Taco reacts to the Rev-9 at Dani Ramos' apartment. Terminator: Dark Fate

Notes

Carl and his dog

• In Terminator 2: Judgment Day, the dogs at Enrique Salceda's ranch do not bark when the "good" Terminator is nearby. It is unclear whether or not this is for a specific reason, such as "dogs can sense anyone who comes with bad intention (or mind)", or if James Cameron simply did not want to confuse audience members by unnecessarily introducing tension into the scene.
• In Terminator: Dark Fate, Carl has a dog as his pet, even though he was never reprogrammed.