Trigger stacking happens to dogs when there are too many sensitive stimuli occurring within short succession of each other. These sensitive stimuli are specific to each dog, but some common stimuli include other dogs, bikes, vacuums, and skateboards. Each stimuli on its own is uncomfortable for the dog, but when there are multiple, it can be overwhelming and go as far as a redirection of the built up frustration.
The threshold is the point at which the dog may no longer become responsive to gain its focus. The goal with our dogs is to keep them under threshold by reducing the excitement, provocation, and tension.