Why might a dog suddenly scratch itself during training?

The story behind the answer

Dogs often scratch mid-training as a displacement behavior—a stress signal that appears when they feel conflicted, over-aroused, or uncertain. Like yawning, lip-licking, ground sniffing, or a full-body “shake-off,” the scratch redirects nervous energy and helps the dog self-regulate. In this context, it’s a cue to pause, simplify the task, clarify your cues, and increase reinforcement to reduce pressure.

By contrast, fleas or allergies cause frequent, context-independent itching, and boredom-related grooming tends to occur in low-stimulation settings, not right when a challenge ramps up. Memory tip: “Scratch = Stress Switch.” When you see it during training, switch your approach—make it easier, keep sessions short, and watch for other calming signals to keep your dog confident and engaged.