Why does my dog react to some people and not to others, when there is no difference between them? The answer is trigger stacking.

When a dog reacts, whether he barks, bites or chases someone away it is because his brain can take no more triggers. A trigger is anything that starts the stress reaction in the dog’s body and mind.

A stress reaction is physical. It’s not something that a dog could control, even if he wanted to, it’s an innate survival response to a threat. Once long ago for both of our species, it was beneficial to us. As we have become physically safer the stress reaction has remained.

Why Stress is Physical

The name given to a sudden influx of stress is “acute”. It culminates in a rush of cortisol and a huge production of adrenaline. The dog cannot control it and yet it feels cripplingly intense.

Think back to a time when you have suddenly been terrified and your knees wobbled, you went lightheaded and lost complete control of your mind, a good example is a near miss if someone cuts you up whilst driving.

The physical stress reaction causes an ancient fight or flight response. The brain goes into fast forward reactive mode. Then if the trigger is removed the brain goes into reverse and the dog starts to calm down. If the trigger gets closer or more threatening in the dog’s mind* then the brain will fast forward at an alarming rate, until the dog reacts.

*It is vital to remember that the dog’s stress reaction is based on his own learning experiences, fears, personality and ability to cope. It is not based on things we may consider to be worrying to him!

Stress Needs Time to Reverse

Whilst the stress reaction may appear quickly and the dog’s brain fast forwards to reactivity, it goes slower when it moves in reverse. This is where trigger stacking comes in. A big stress trigger can take a dog thirty-six hours for recovery. If we add more stress triggers, whilst the dog’s brain is in reverse, the brain goes into an unhealthy forward and reverse battle. More stress triggers mean more arousal and eventually the dog will reach his limit (threshold) and react.

This is exactly why a dog can walk past five people and react at the sixth.

So what can you do to help your reactive dog? Take a look at our advice for Reactive Dog – First Aid.

Trigger Stacking

What is Balanced Dog Training?

The term ‘balanced’ means the trainer is using all four learning styles (known as quadrants, if you like the jargon), as acceptable dog training methods – but what exactly does that mean?

An Open Letter to Stan Lee

“he is much like McDonald’s, but we wouldn’t use their commercial success as a basis for educating children about proper nutrition”

Dog Professionals – This Is For YOU!

Working with dogs and their people is a tough job, but someone has to do it. Thankfully that someone is you, so for your sanity remember this:

Emma Smith

ES Pet Care

Do you manage your mind and your world to stay safe from compassion fatigue as a dog professional?

Why Does My Dog Ignore Me?

How often does your dog ignore you? Do they appear to stop, listen and then carry on anyway? Do you feel like you’ve tried everything?



  1. Reactive Dog - What's Going On? | Canine Principles - […] first thing we do is find the triggers and as much as we can, remove them from the dog’s…
  2. Dog Behaviour Advice – Recall! | Canine Principles - […] is the best option at the time, he will come back. It’s simple behavioural science based on brain chemistry…
  3. Why Does My Dog Ignore Me? | Canine Principles - […] way beyond your current skill-set. Add the pressure of being shouted at and you’re understandably stressed. Pressure and confusion…
  4. Electric Dog Collars - Training or Torture? | Canine Principles - […] after use of electricity the behaviour will come back stronger, more severely and be more easily triggered. Which makes…
  5. What is Balanced Dog Training? | Canine Principles - […] things wrong, his self-confidence will drop and he is likely to stop trying. Punishment induces a stress reaction, because…

Submit a Comment

Your email address will not be published. Required fields are marked *

Pin It on Pinterest

Share This