If you remember one idea from everything we write about reactivity, make it this one: threshold. Your dog’s threshold is the line between handling a situation and falling apart in it. Learn to see that line, and you can do almost everything else in the reactive dog playbook. Miss it, and even good techniques will not stick.
What threshold means
Below threshold, your dog notices a trigger but can still function. They can take a treat, glance back at you, and move with you. Above threshold, the thinking part of the brain goes offline. Food gets spat out or ignored, cues stop working, and your dog barks, lunges, or shuts down. This is not stubbornness. A flooded brain genuinely cannot learn, which is exactly why over-arousal makes training so hard.
How to read your dog’s threshold
Your dog will tell you where their line is, if you watch. Early warning signs usually show up well before the bark:
- A hard, fixed stare at the trigger
- Stiffening or freezing, even briefly
- Closed mouth after being relaxed and panty
- Ears pinned or sharply forward
- Refusing food they would normally take
That last one is the cleanest test there is. If your dog will not eat a high-value treat they would happily take at home, you are too close, and it is time to add distance.
Working under threshold
The goal of nearly every reactivity session is to stay in that zone where your dog notices the trigger but stays calm enough to engage with you. From there you can play the engage-disengage game or set up a session that does not backfire. Push past the line and you are not training, you are rehearsing the reaction.
Threshold moves around
Your dog’s threshold is not a fixed number of feet. It shifts with the trigger, the day, and how much stress has already piled up. A long, sniffy decompression walk can widen it, while a stacked-up stressful morning can shrink it dramatically. That moving target is the heart of trigger stacking, and it is why choosing a calm walking route matters so much. When you respect the line, you protect your dog’s progress. Learn to spot the moment a dog goes over threshold so you can act early.
