Your Dog's Internal Safety Switch

Safety is the name of the game when we are living with a dog who seems to overreact to the World around them. And safety will always incorporate knowledge and awareness of the dog’s nervous system responses including the vagus nerve.

The vagus nerve is like an internal thermostat for stress. When it's working well, your dog can encounter something mildly stressful (another dog across the street, a loud noise, a stranger approaching) and their body knows how to respond proportionally and then return to calm. Their heart rate might spike briefly, but it settles back down. They notice the trigger, assess it, and move on.

But when the vagus nerve isn't functioning optimally, your dog is stuck. They're living in a body that can't properly distinguish between real danger and everyday stress. Their system is constantly on high alert, unable to downregulate, unable to return to calm.

And this is why training doesn’t work for dogs who overreact. Because you can't train your way out of a dysregulated nervous system any more than you can think your way out of low blood sugar.

Research has demonstrated something remarkable: heart rate variability (HRV), a measure of vagus nerve function, is able to distinguish between positive and negative emotional situations in dogs. Scientists can literally see the difference in a dog's nervous system when they're experiencing joy versus fear.

Even more telling? Dogs with bite histories had significantly lower heart rate variability. Owner-reported aggression negatively correlated with HRV, demonstrating that dogs with a history of biting show poorer autonomic regulation.

Dogs who bite aren't choosing to be aggressive. They're operating with nervous systems that can't regulate properly.

Imagine waking up every morning with your heart already racing slightly. Your stomach feels tight, unsettled. There's a background hum of anxiety that you can't quite name or shake. You go about your morning, but everything feels a bit too loud, a bit too fast, a bit too much.

Then it's time to go outside, the thing you're supposed to enjoy, but the moment you step through the door, your system ramps up further. Every person you see could be a threat. Every dog could attack. Every sudden noise sends a jolt through your body. And the worst part? You have no control over when these encounters will happen or how close they'll get.

Your lead (the thing that's supposed to keep you safe) actually prevents you from escaping. So when something scary approaches, you only have two options: bark and lunge to make it go away (fight) or shut down completely and wait for it to pass (freeze). Flight isn't available to you.

And here's the really cruel bit: the humans you love, and trust keep putting you in these situations. Over and over again. They seem confused about why you're upset. Sometimes they get frustrated with you. Sometimes they pull you closer to the scary thing. You try so hard to tell them you can't cope, but they don't seem to understand.

This is what it's like to live with a dysregulated nervous system. This is the daily reality of many dogs.

Another sinister way that we treat dogs is ignoring them as we walk them. Perhaps even putting walking aids onto them to stop their fear related behaviour, without considering how they feel or why they feel it.

How many ways do you think the dog in the picture above is being disempowered or not considered? Try looking at the image again and imagining the dog is a child, or even yourself. How would you feel? 

Now imagine how feeling that way would change your behaviour if you saw something really scary!

You will only be able to understand your dog if you're watching them. Become an avid dog watcher, look for the following changes, learn what sends the from safety to panic. 

But here's where it gets even more complex, and more hopeful.

Research shows that the heart rate variability of a dog and their owner adapt to each other during interaction. The owner's high heart rate variability is connected to the dog's high heart rate variability during calm periods.

Your dog’s system is reading your nervous system too. When you're stressed about the walk, anxious about potential reactions, braced for problems, your dog feels all of that. Their system mirrors yours.

This certainly isn't about blaming you. It's about understanding that you and your dog are in this together, quite literally. Your nervous systems are in constant conversation with each other.

When you're dysregulated, your dog picks up on it and becomes more dysregulated. When you're calm and grounded, it helps your dog access calm too. But if their nervous system is already compromised, they need more than just your calm presence. They need their own system to heal.

Traditional dog training operates on the assumption that dogs can learn and respond to cues when properly motivated. And that's true, for dogs with regulated nervous systems.

But a dog with poor vagal tone, with low heart rate variability, with a dysregulated autonomic nervous system? They can't access the learning parts of their brain when they're triggered. They're operating from survival mode, not thinking mode.

You can't reinforce your way out of a nervous system problem. You can't reward it away. You can't punish it into submission. The body simply doesn't work that way.

This is why your reactive dog might be perfect in training class but falls apart on the street. It's why they can focus beautifully at home but become a completely different dog the moment they step outside. It's not that they're being stubborn or defiant. It's that their nervous system is overwhelmed, and when that happens, training goes out the window.

Your dog’s system is reading your nervous system too. When you're stressed about the walk, anxious about potential reactions, braced for problems, your dog feels all of that. Their system mirrors yours.

This certainly isn't about blaming you. It's about understanding that you and your dog are in this together, quite literally. Your nervous systems are in constant conversation with each other.

When you're dysregulated, your dog picks up on it and becomes more dysregulated. When you're calm and grounded, it helps your dog access calm too. But if their nervous system is already compromised, they need more than just your calm presence. They need their own system to heal.

So what does a dog with a dysregulated nervous system need?

Safety. Real, felt safety. Not just an absence of punishment, but an active presence of nervous system support.

They need:

1. Predictability. A life where they know what's coming next, where surprises are minimised, where their world feels manageable.
2. Choice and control. The ability to move away from things that scare them, to set their own pace, to have agency in their environment.
3. Nervous system regulation support. This might include targeted exercises to stimulate the vagus nerve, activities that promote calm, environments that reduce rather than increase stress.
4. A calm, regulated human. Your dog needs you to work on your own nervous system too. When you can stay grounded and present, even in difficult moments, you become a resource for your dog's system.
5. Time. Healing a dysregulated nervous system doesn't happen in six weeks of training class. It happens slowly, incrementally, with patience and understanding.

Understanding that your dog's reactivity stems from a dysregulated nervous system means approaching the problem differently.

It means recognising that when your dog barks and lunges, they're not being naughty. They're showing you that their nervous system is overwhelmed and they don't feel safe.

It means accepting that quick fixes and forceful methods won't work because you can't intimidate a nervous system into regulation. If anything, adding fear only makes the dysregulation worse.

It means being willing to slow down, to prioritise your dog's felt sense of safety over what looks good to other people, to trust that small improvements in nervous system function will eventually lead to big changes in behaviour.

The training will work better when the nervous system is ready. Until then, focus on regulation. Focus on safety. Focus on connection.

Because a calm nervous system is the foundation everything else is built on.

You can't reinforce your way out of a nervous system problem. You can't reward it away. You can't punish it into submission. The body simply doesn't work that way.

This is why your reactive dog might be perfect in training class but falls apart on the street. It's why they can focus beautifully at home but become a completely different dog the moment they step outside. Their nervous system is overwhelmed, and when that happens, training goes out the window.

Your dog’s system is reading your nervous system too. When you're stressed about the walk, anxious about potential reactions, braced for problems, your dog feels all of that. Their system mirrors yours.

This certainly isn't about blaming you. It's about understanding that you and your dog are in this together, quite literally. Your nervous systems are in constant conversation with each other.

When you're dysregulated, your dog picks up on it and becomes more dysregulated. When you're calm and grounded, it helps your dog access calm too. But if their nervous system is already compromised, they need more than just your calm presence. They need their own system to heal.

Learn more with the following ebook!