When Pain Changes Behavior: What Dogs and Humans Have in Common
Right now my back is out. I re-injured something in my back, and I am living with a level of discomfort that I have not dealt with in a while.
The result of that is I have found myself shorter with my dogs. My tolerance for Letty’s need to be attached to me has been lower. Sounds that he makes, sounds he has made countless times before, are suddenly grating in a way they never used to be. And it is not that his behavior has changed. It is that my capacity to tolerate those normal dog behaviors is temporarily reduced because of pain.
And that got me thinking.
We are really good at expecting our dogs to tolerate weird human things. Clothes. Harnesses. Confinement. Proximity to strange people and animals. Noise. Routines that prioritize our work and schedules. We ask them to tolerate all of that and then some. And most of the time, many dogs do. But do we stop to consider how physical discomfort changes their capacity to tolerate all of that?
If I were at the gym and someone said something once, maybe I would laugh it off. But when my back is out, I am irritable. My baseline is different. My threshold for discomfort is lower. That does not mean I am a bad person. It means pain changes experience.
Dogs are no different.
Pain and Behavior: A Biological Connection
Research in both human and animal science is clear. Pain changes behavior. Pain does not just cause physical reactions. It changes motivation, increases vigilance, reduces tolerance, and alters how an individual interacts with the world.
A few key points from the science:
Pain is a stressor. Chronic or unresolved pain activates the stress response system. Stress hormones influence arousal, emotional reactivity, and attention.
Pain reduces behavioral flexibility. Animals experiencing pain are less able to shift attention, regulate reactions, or tolerate even low level discomfort. Their nervous systems prioritize protecting the body.
Pain reshapes reinforcement. Activities that once felt rewarding can feel aversive when they cause discomfort. A dog who once loved being petted on the hips may flinch or withdraw if those areas hurt.
Pain can create learned patterns. Even after the underlying pain is resolved, the behavioral response to that pain can persist. Dogs may avoid certain movements, people, or touches because their nervous system rehearsed those protective responses.
This is not acting spoiled or manipulating. It is biology.
And yet, when dogs are in pain or discomfort, we often interpret their responses through a behavioral lens alone, without considering the physical context underneath.
The Human Side: Pain, Tolerance, and Dogs
It has been humbling to notice how my own pain has changed my interactions with my dogs. Letty’s sounds, nothing new for him, are driving me crazy right now. Rumor’s normal snuggle preference, where she wants to be draped over me like a living blanket, feels impossible at the moment. My body simply cannot tolerate close physical contact in the ways we normally enjoy it.
And I love them. I literally could not function a day without them. But my capacity right now is different.
And that is important to acknowledge as someone who works with dogs for a living.
If I, a person obsessed with my dogs, find my tolerance lowered by pain, we need to ask a hard question.
What happens when our dogs are in pain and we do not account for it?
Behavior as Communication, Not Defiance
The dogs I work with clinically tell me something similar all the time. Around 80 percent of the cases I see have a pain or health component. Sometimes it is obvious. Lameness. Chronic conditions. Aging discomfort. Sometimes it is subtle. Dental pain. Muscle tension. Joint discomfort hidden under the hood of behavior.
When dogs have physical discomfort, it alters their experience of the world. It shifts what they can tolerate, how they communicate, and how they recover from stressors.
A dog in pain does not simply need more training. They need assessment of physical comfort, adjusted expectations, environmental accommodations, time and support for recovery, and skills built on a foundation of physical and emotional safety.
What This Means For You and Your Dog
If you find yourself thinking:
My dog used to tolerate this, but now they do not
My dog seems grumpy or different
My dog reacts over small things that never used to bother them
My dog avoids touch or certain movements
My dog loses patience faster than they used to
There is a reason behind that. It might be physical. It might be emotional. And those pieces matter.
Dogs do not operate in a vacuum. Pain changes what they can do long before it changes what they should do.
Our job as caregivers is not to demand tolerance in spite of discomfort. It is to notice discomfort, understand it, and adjust expectations so learning can happen.
A Reminder: Animals Are Not Robots
I cannot tolerate Rumor snuggling me the way she normally does right now. That does not mean I love her any less. It means my body is temporarily limited. That is okay. That is human.
Likewise, if your dog is less tolerant than usual, it might not mean they are stubborn, disobedient, or acting out. It might mean they are in pain. And pain changes behavior before it becomes obvious.
Behavior is communication. Behavior is information. And pain is a powerful piece of that information.
A Better First Step Than Fixing Behavior
Before adding more training pressure, ask:
Is this a pain issue?
Does this dog have the capacity right now to meet this expectation?
Is there something physically uncomfortable influencing this behavior?
Once pain is addressed and comfort is restored, there is often a second layer to the behavior. The learned responses created during the painful period.
That means even when pain is resolved, the behavior may not disappear immediately. It may need to be rebuilt gently with reassurance, gradual exposure, supportive skills, and reinforced choices rather than forced performance.
Final Thought
Pain is not a fringe explanation for behavior challenges. It is fundamental physiology. It is a baseline experience that shapes how a nervous system functions. And it is something we all experience, humans and dogs alike.
Right now, my tolerance is lower. My dogs are aware of that. And I am learning from it.
Maybe this perspective will help you notice something new in your dog.
Behavior is communication. And discomfort deserves to be heard.