Before We Talk About Behaviour Change, We Need to Talk About Health

When supporting behaviour change in dogs, it is critical that we begin with a thorough understanding of the dog’s physical state — not simply their observable behaviour.

Behaviour never happens in isolation. A dog’s physical health and internal state will interact with how they feel, how they learn, and how they relate to their environment and the people around them. If we miss part of this picture, we risk misunderstanding the behaviour and putting in place interventions that are ineffective or may even cause further distress.

If a dog is struggling with behaviour that seems sudden, puzzling, or difficult to change, it’s important to ask whether there may be an underlying physical cause.

What I’m Seeing in Dogs I’m Supporting

I’ve seen this very clearly in several recent cases. Quite a few of the dogs I’ve supported lately were experiencing both pain and gastrointestinal issues — and the behaviours that brought them to behaviour support were strongly linked to this internal discomfort.

Distance-increasing behaviours such as growling, barking, and even biting were common in these cases. In each one, once we recognised and addressed the underlying pain and gut health issues, the dog’s behaviour began to change in ways that were not possible through behaviour modification alone.

What the Research Tells Us

Numerous studies have shown that physical discomfort, including pain and gastrointestinal (GI) issues, can cause problem behaviours in dogs.

A comprehensive 2020 review — the Mills paper on pain and behaviour — summarises a wide body of research and clinical cases illustrating how behaviours such as aggression, avoidance, anxiety, and frustration may be underpinned by pain. The review also highlights that when pain is treated, these behaviours often resolve or significantly improve, whereas behaviour modification alone is unlikely to succeed if underlying discomfort persists.

Gastrointestinal discomfort is another key contributor. The Mills paper notes that GI pain and discomfort, including conditions such as inflammatory bowel disease, are associated with increased anxiety and aggression. The review also highlights growing interest in the gut–brain axis, which provides clear physiological pathways linking gastrointestinal health and behaviour.

This reminds us that health must come first. Attempting to implement behaviour change in a dog experiencing unresolved pain or GI discomfort is unlikely to be effective, and may compromise the dog’s welfare.

Key Considerations to Keep in Mind

👉 Pain and discomfort affect behavioural responses
When pain or GI discomfort is present, the dog’s nervous system is receiving a persistent signal of threat from within the body. This affects how the dog responds to their environment, often resulting in defensive behaviours. Behaviour modification strategies cannot override this internal state.

👉 Readiness for learning
For a dog to engage successfully in new learning, their nervous system needs to be in a state that supports curiosity, exploration, and engagement with their environment. Chronic discomfort suppresses these capacities, making learning more difficult and less stable.

👉 Behavioural regression
Fluctuating physical health can explain why some dogs show initial improvement, then regress. If pain or GI symptoms flare, behaviour changes are likely to regress.

👉 Changes in thresholds and tolerance
When a dog is experiencing pain or discomfort, their behavioural thresholds are often lower — meaning they are more likely to react or struggle in situations they might usually tolerate. You may see increased sensitivity to touch, sound, movement, or proximity. Without addressing the underlying discomfort, this increased reactivity will often persist.

👉 Reinforcement is less effective when discomfort is present
Pain and GI discomfort affect how the brain processes reinforcement. When a dog is in discomfort, food rewards, play, and social interaction may have less value, or may not be effective in supporting behaviour change. This is one reason behaviour modification often stalls when underlying physical issues are not resolved.

👉 Addressing pain and discomfort can resolve behaviour concerns without further training
When the behaviour is a response to pain or discomfort, resolving the underlying issue can sometimes remove the need for further behaviour support altogether. Once the dog is no longer in discomfort, behaviours that were driven by defensive coping strategies may simply disappear. In these cases, behaviour modification is not what brings change — supporting the dog’s physical wellbeing does.

What Does This Mean for You?

Resolving any underlying discomfort is one of the most important things you can do to support your dog and for behaviour change to be possible. If your dog is dealing with pain or discomfort, no behaviour plan can truly help until that’s addressed first.

As the Mills paper states:
"Pain and discomfort are commonly overlooked causes of problem behaviour… The behaviour may not resolve until the source of pain is addressed."

Supporting your dog’s wellbeing always comes first. And when we do that, we often find that behaviour change follows more easily — sometimes with no further intervention needed at all.