Many behaviour problems in dogs – from reactivity to withdrawal – may actually be signs of pain.
Here’s what every dog guardian needs to know before jumping into training.
When Behaviour Is a Clue, Not the Problem
I’ve lost count of how many dogs have come my way for behaviour issues, only for me to uncover a list of behaviours that were red flags for pain.
It might show up as grumpiness during grooming. A dog suddenly avoiding the stairs. A normally friendly dog growling when someone leans in for a cuddle. And sure, sometimes it is just behaviour. But not always. And not nearly as often as people think.
When a dog starts acting differently, it’s tempting to jump straight into training. But training isn’t always the answer. Sometimes, it’s a clue. And the real answer lies in a vet’s consult room, not a treat pouch.
Subtle Signs of Pain in Dogs: Behavioural Clues to Watch For
Here’s the tricky thing about dogs: they’re ridiculously stoic. Most of them won’t whimper or cry when something hurts, especially when it’s chronic. They won’t make a fuss. Instead, they cope. They adjust. Until they can’t.
And that’s when we start seeing behaviour changes. Not because they’re being difficult, but because they’re trying to avoid something that hurts. Or they’re exhausted from the constant discomfort. Or they just don’t have the capacity anymore to tolerate what they used to.
In a recent study, Kwik et al. (2025) looked at ten dogs who were referred for behaviour work. Seven of them turned out to have pain that hadn’t been previously diagnosed. In many cases, behaviour changes were the only clue something was wrong.
Some of the signs those dogs showed? Things like:
- Growling or snapping when handled
- Avoiding social contact or play
- Suddenly becoming reactive to dogs or people
- Sleeping more, or sleeping less
- Refusing to go on walks or climb stairs
None of those dogs were limping. There were no clinical signs in the clinic, either. It took further diagnostic imaging and tests to uncover the truth.
What Research Says About Pain-Related Behaviour in Dogs
This isn’t just one-off anecdotal stuff. There’s a growing body of research that paints a clear picture:
Pain and behaviour are tangled up in ways we’re only just starting to truly understand.
- Mills et al. (2020) make it clear that pain is often overlooked in animals with behaviour problems. They suggest that any significant change in behaviour should prompt a pain investigation. Not as an afterthought. As a first step.
- In Mills et al. (2023), they explore the idea that discomfort and odd nerve sensations (like tingling or pins and needles) can change how animals feel, think, and respond to the world around them. Imagine how irritable you get when you’ve got backache or a trapped nerve — now imagine trying to do obedience training on top of that.
- Mills et al. (2019) look at chronic pain specifically, and how it reshapes emotional processing in the brain. Dogs in long-term pain can become more anxious, more sensitive to stress, and more reactive. Their emotional resilience starts to wear thin.
That little grumble when you brush their side? It might not be a training issue. It might be the only way they can tell you they’re not okay.
Common “Behaviour Problems” That Might Have a Pain Link
This is where it gets muddy. Pain rarely looks neat and tidy. But here are some behaviours I see regularly that turn out to have a physical component:
- Snapping when touched or groomed
- Growling when approached, especially when resting
- Reactivity on walks that seems to come from nowhere
- A dog who used to love play suddenly avoiding it
- Noise sensitivity that appears out of the blue
- Restlessness, pacing, or struggling to settle
- Obsessive licking or chewing, especially limbs or flanks
- General grumpiness that feels “out of character”
I’m not saying these are definitely caused by pain. But they’re common indicators. And they’re worth exploring, especially if training alone isn’t working as you might expect. If you’re already working on reactivity and feel like something’s missing, you might also find my calm strategies using Behaviour Razors helpful for getting back to basics in a more connected way.
Why It Often Gets Missed (and Why That’s Not Your Fault)
Now, before the guilt kicks in — breathe. Pain can be incredibly hard to spot.
Dogs are masters of compensation. They’ll avoid certain movements or subtly change how they lie down. They might tolerate a situation one day, and react to it the next. It’s inconsistent. It’s messy.
And most vet appointments? 10–15 minutes. In a bright, clinical room. With a stranger poking and prodding. Anxious dogs clamp down, stoic dogs bluff their way through. That’s not a criticism of vets — they’re doing their best. But they don’t get to see what you see at home.
That’s where you come in. Your observations are gold. The thing that makes the invisible visible. Things like:
- What happened before the behaviour?
- What was different that day? (Long walk? Visitors?)
- Have you seen a gradual shift over time?
- Can you capture it on video?
I often send clients back to their vet before we even start behaviour work. And when we do work together, I help them collect evidence to support that vet visit — videos, notes, timelines. Anything that builds the picture.
That collaboration often leads to diagnosis. To relief. And to a dog who finally starts behaving like themselves again.
That’s exactly why I only work under vet referral. It’s not just a policy, it’s a safety net. Pain is so often a piece of the puzzle that trying to assess behaviour without a vet’s input would be like doing detective work with half the clues missing. Your dog’s health and wellbeing come first, and that means making sure we’re not missing a physical cause behind their behaviour.
How Chronic Pain Affects Dog Behaviour and Learning
Chronic pain is slippery. It doesn’t just make dogs sore. It messes with how they feel.
Dogs in pain may:
- Startle more easily
- Struggle to learn or retain information
- Avoid interaction
- Get more snappy, more sensitive, more stuck
Mills et al. (2019) show how chronic pain affects brain chemistry. It amplifies negative bias — so a dog is more likely to see the world as threatening. It erodes emotional regulation. It makes fear harder to shake.
So if training feels harder than it should… If progress is stalling… If your dog seems switched off or on edge…
There might be more going on than stubbornness or confusion. There might be something physical tipping the scales.
What You Can Do (Even If You’re Not Sure)
If something doesn’t feel right, trust that. You know your dog. You’re the one who sees them every day. The one who notices the subtle shifts.
Here’s what you can do:
1. Start a behaviour diary. Jot down what you notice. When things happen. What your dog did earlier in the day. Patterns often emerge with just a few days of notes. I’ve written more about how reflective practise helps when you’re living with a reactive or sensitive dog. Because noticing patterns isn’t just good for your dog, it’s a form of support for you too.
2. Film your dog. Especially during movements (stairs, jumping into the car), rest, and interactions. Try to capture what’s normal as well as what’s concerning.
3. Take them to your vet. And if your vet says they’re not sure? Ask for a pain trial. Or a second opinion. Or a referral. You’re not overreacting.
4. Download my free guide. It walks you through the key red flags and what to share with your vet.
5. Ask for help. If you need support figuring all this out, that’s what I’m here for.
Final Thoughts: Your Dog’s Not Broken. And Neither Are You.
It’s hard, isn’t it? Living with a dog who suddenly feels like a stranger. Dealing with behaviour that doesn’t make sense. Wondering if you’re doing something wrong.
But the truth is: behaviour is communication. And pain is one of the most common messages dogs are trying to send.
If something in this blog resonates, or if you’re nodding along thinking, “That’s exactly what we’re dealing with…” — reach out. You don’t have to navigate this alone.
References:
- Kwik, K., De Deuster, T., Bosmans, T. & Mottet, J. (2025). Detection of maladaptive pain in dogs referred for behavioral complaints: challenges and opportunities. Frontiers in Behavioural Neuroscience. [https://doi.org/10.3389/fnbeh.2025.1569351]
- Mills, D. S., Demontigny-Bédard, I., Gruen, M., Klinck, M. P., McPeake, K. J., Barcelos, A. M., Hewison, L., Van Haevermaet, H., Denenberg, S., Hauser, H., Koch, C., Ballantyne, K., Wilson, C., Mathkari, C. V., Pounder, J., Garcia, E., Darder, P., Fatjó, J., & Levine, E. (2020). Pain and Problem Behavior in Cats and Dogs. Animals, 10(2), 318. [https://doi.org/10.3390/ani10020318]
- Mills, D. S., Coutts, F.M. & McPeake, K.J. (2024). Behavior Problems Associated with Pain and Paresthesia. Veterinary Clinics of North America: Small Animal Practice, 54(1), 55-69. [https://doi.org/10.1016/j.cvsm.2023.08.007]
- Mills S. E. E., Nicolson K. P. & Smith B. H. (2019) Chronic pain: a review of its epidemiology and associated factors in population-based studies. British Journal of Anaesthesia, Aug;123(2):e273-e283. [https://doi.org/10.1016/j.bja.2019.03.023]