Every reactive dog has a distance where they can notice another dog and still take a treat and listen to you. That distance is their threshold. Training that stays on the calm side of it is where progress happens.
The three zones
It helps to think of the space around another dog as three rings:
- Green zone. Your dog sees the other dog but can still eat, sniff and respond to you. Their body is loose.
- Yellow zone. Your dog stares, goes stiff, or stops taking food. They can often still turn away with help.
- Red zone. Your dog barks, lunges, whines or spins. They can't take food or listen right now.
Learning happens best in the green zone. In the red zone your dog is too upset to learn anything new, and every reaction is practice at reacting.
How to find your dog's distance
Watch a few walks with fresh eyes. You're looking for two numbers:
- The distance where your dog first notices another dog: a head turn, ears forward, a pause.
- The distance where they bark or lunge.
Then ask: at that first distance, will they take a treat? If the answer is "sometimes" or "no," the green zone starts further out.
A good starting distance is at least one and a half times your dog's bark-or-lunge distance, and no closer than the point where they first notice. Add more room if they struggle to take food, or take more than a few minutes to settle after a reaction.
The free Threshold Finder does this math for you and draws the rings.
Why the number changes
Threshold isn't a set number. It shifts with the day:
- A tired, stressed or unwell dog has a shorter fuse. See trigger stacking.
- A dog coming straight at you is harder than one walking past, or one behind a parked car.
- A small, quiet dog is often easier than a big, bouncy one.
So treat the number as a starting point, not a rule. If your dog is struggling, add distance. If they're relaxed and eating, you're in the right place.
Closing the gap
Once your dog is reliably calm at the starting distance, you can move closer in small steps. A useful rule is to change one thing at a time: distance, how long you stay, or how much the other dog is moving. If your dog tips into yellow or red, back off to where they were last relaxed.
Keeping a simple log helps. Note the closest distance where your dog stayed calm and their worst reaction on each walk. Over a few weeks the pattern is easier to see than it is day to day.
Games that work at threshold
At the edge of the green zone, two games do a lot of work:
- Look At That: your dog looks at the other dog, then gets a treat.
- The emergency U-turn: a cheerful cue to turn and walk away when a dog appears too close.
Both are built on the same idea: seeing another dog predicts something good, and there is always a way out.