Dogs are well-known for their ability to detect Infiltrator units. They frequently start barking when an Infiltrator gets close to them.
Ever since Skynet developed T-800 Infiltrators with living tissue over a metallic endoskeleton, the Resistance has had a hard time 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 allow dogs to sniff hands and this is 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.
- At the home of a wrong Sarah Connor, a very small breed of dog reacts to the T-800.
- Dogs, which appear to be German Shepherds, at the Resistance bunker checkpoint react to a Terminator.
- A dog, another German Shepard, at the Tiki Motel reacts to the T-800.
- Sarah Connor brings an Alsatian dog with her, presumably because of dogs' ability to detect the Terminators.
- John Connor's dog, Max, reacts to a T-1000.
- The stray dog pack at Mary Randall's safe house in Los Angeles react to C890.L.
- Mary Randall recollects patrolling the Future War with dogs and detecting a Terminator in a poncho.
- The puppy Dieter von Rossbach wanted to give to John reacts to the T-800 they destroyed at Connor's safe house in Paraguay.
- The dogs in Carlos' house react to Cameron.
- Young Kyle Reese met a German Shepherd in a sewer where the dog barked at the presence of a Terminator coming in.
- 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.