Could Your Dog’s Reactivity Be Caused by Pain?

One of the first questions I ask when working with a reactive dog is: Could there be something physical going on?

Pain is such a common and sadly, often missed contributor to behaviour change in dogs. We’re so used to thinking of reactivity as just emotional or behavioural. But more often than not, there’s a physical layer too.

Dogs don’t always look like they’re in pain

They’re incredibly good at hiding it. Many dogs will adapt and mask discomfort for weeks, months, even years until it either becomes too much, or shows up in different ways.

And those “different ways” often don’t look like limping or crying. They look like:

• Barking more, especially in situations they previously coped with
• Becoming snappy or short-tempered
• Seeming more on edge or “tense” in new places
• Avoiding touch or grooming
• Slowing down on walks or hesitating on stairs
• Sudden clinginess or sudden grumpiness
• Struggling to relax at home
• Losing interest in training or seeming frustrated

These are the little things we notice in hindsight when something changes in our dog and we can’t quite put our finger on why.

Behaviour is communication

When dogs are uncomfortable, they find ways to tell us but their language is different to ours. A growl might be a warning, not aggression. Barking might be a sign of overwhelm. Even something as small as a change in sleeping position can be a clue.

We don’t want to pathologise every quirk. But it’s important to stay curious. If something feels off with your dog’s behaviour, pain is always worth considering.

It’s not just about training

As trainers, we always want to set dogs up to succeed. That means making sure they feel good in their bodies especially when working through challenging behaviours like reactivity.

That’s why, for some dogs, we suggest a check-in with a qualified physio before or during their training journey. It’s not about finding problems it’s about ruling things out, or gently supporting dogs who might have been compensating without us realising.

You know your dog best

If you’ve noticed changes in your dog’s mood, tolerance, or behaviour trust your instinct. It doesn’t always mean something serious is going on, but it does mean your dog might need a little extra support.

Pain and behaviour are deeply connected. And the more we understand that, the more compassionately and effectively we can help our dogs.