"He doesn't want to get in the car anymore."

"He growls when I put his harness on."

"He doesn't jump on the couch anymore, even though he always used to."

"He doesn't listen like he used to."

Veterinarians hear these phrases every day. And the reaction is often the same: people think the dog has become more stubborn, lazier, grumpier, or that he's simply trying to do what he wants as he gets older.

This is understandable. We tend to interpret behavioral changes through a human lens. When a person refuses to do something, we look for an intention. In dogs, this logic can be misleading.

For about twenty years, veterinary behavioral medicine has emphasized a point that remains largely underestimated: behind a behavior deemed "difficult" may lie pain.

Not in all cases, of course. Some problems are indeed related to training, learning, or emotions. But before concluding that it's a behavioral disorder, current recommendations suggest ruling out a medical cause, especially pain.

Because a dog in pain doesn't always express his pain in the way we imagine. A dog that is in pain doesn't necessarily whimper or limp. He may continue to play, chase a ball, or go for walks enthusiastically. However, certain movements gradually become more difficult, some manipulations are less well tolerated, and certain situations are avoided.

For the owner, this sometimes looks like reluctance, whereas for the dog, it's often a way to limit discomfort.

What science establishes

Today, the link between pain and behavior is well documented.

In their reference review published in 2020, Mills and his collaborators recall that pain can be at the origin of a behavioral disorder, aggravate it, or complicate the clinical picture so much that it becomes difficult to distinguish what is behavioral from what is a medical problem.

In other words, when a dog suddenly changes its attitude, pain is one of the first hypotheses to consider.

More recent work by De Keuster and his team leads to the same conclusion. By studying dogs referred for behavioral problems, the authors show that a significant proportion actually have an unnoticed painful component. Not because the examinations were poorly performed, but because this pain is sometimes subtle, fluctuating, or difficult to highlight.

This is probably why it is still so often underestimated.

We all have in mind the image of a suffering dog: an animal that limps distinctly, cries, or completely refuses to move, but the reality is often much more subtle.

Some dogs continue to lead an almost normal life. They eat, play, ask for their walk... but start to avoid very specific movements. They hesitate before getting into a car, no longer want to jump on a couch, growl when a sensitive area is handled (or touched), or even seem less enthusiastic in certain situations. Taken separately, each of these signs seems insignificant, but put together, they can tell a whole different story...

Why pain so often resembles "character"

One of the reasons is simple: a dog doesn't understand why it hurts. However, he quickly learns which situations trigger that pain.

If getting in a car causes hip discomfort, he will hesitate more and more. If putting on a harness pulls on a painful area of the neck or shoulders, he will back away when it's taken out. If sitting becomes uncomfortable, he will prefer to stand. From the outside, it easily gives the impression that he refuses to obey. In reality, he is simply looking for the least painful solution.

Chronic pain also has another peculiarity: it is not always constant. A dog may seem perfectly at ease during a walk because the excitement momentarily masks his discomfort. Then he comes home, struggles to lie down, hesitates to get up, or becomes more irritable a few hours later. Conversely, some are particularly stiff upon waking before regaining almost normal locomotion after a few minutes. These variations often disconcert owners. We then hear: "But yesterday he was running," or "At the vet, he showed nothing." It is precisely this fluctuating nature that makes pain difficult to recognize (and the reason why we insist on telling you to video record your dog's symptoms to show them to veterinarians). 

Finally, some dogs end up anticipating the pain. Even before a movement becomes genuinely painful, they avoid the situation, tense up when handled, or growl to prevent contact they know will be unpleasant.

This phenomenon is well described in the work of Barcelos and his team on occult musculoskeletal pain in dogs presented for aggression. In some animals, it was not a character problem that explained the defensive reactions, but rather pain that had gone unnoticed for a long time.

This is undoubtedly one of the most common pitfalls: interpreting as stubbornness a behavior that is actually an avoidance strategy.

The most frequently misinterpreted behaviors

“He no longer wants to get in the car, on the couch, or go up the stairs.”

This is probably one of the most frequent changes... and also one of the most trivialized. At first, the dog hesitates for a few seconds. Then he waits for help. Finally, he gives up completely. We often think he's getting old, becoming lazy, or simply no longer wants to. However, when a dog who used to jump effortlessly gradually stops doing so, pain is one of the first hypotheses to consider. Getting into a car boot, climbing a few steps, or jumping on a couch puts a lot of strain on the hips, knees, shoulders, back muscles, and spine. If any of these movements becomes uncomfortable, the dog quickly learns to avoid it. So the problem isn't that he refuses to obey. The problem may be that he has associated the movement with pain and refuses to be in pain.

“He growls as soon as you touch him.”

The harness, brushing, grooming, handling paws, or simply a caress on the back. These are all situations that can become unpleasant when an area is painful. In these cases, growling is not necessarily a sign of aggression. It can simply be a warning signal.

The dog warns before the manipulation causes more discomfort. Scientific literature also shows that pain lowers the tolerance threshold and promotes defensive reactions. A usually very patient dog can suddenly become irritable when a sensitive area is touched. The appearance of a growl in a specific context therefore always deserves to ask whether pain could explain it.

A little personal aside: in my case, this is something I understood with Fidji. Before I knew she had arthritis, she adored my cats. One of them even used to climb on her to sleep against her. She would let him do it without a problem. Then one day, she growled at him. It wasn't in her character, and at the time, the behavior seemed more than strange to me, and indeed I hadn't understood at all (she had never had an ounce of aggression in her). Shortly after, I learned she had arthritis. In retrospect, that growl probably wasn't a rejection of the cat at all. It was, I think, simply a way of saying: "Hey, when you step on me, it hurts."

"He's grumpier in the evening or after a walk."

Many owners notice that their dog seems different depending on the time of day. He's stiffer when he wakes up, he recovers less well after an outing, he seems more irritable in the evening, or he hesitates more to get up after a nap.

All these small variations are compatible with chronic pain, especially when it affects the joints or the spine. This also explains why some dogs can run for a few minutes on a walk, then have a lot of difficulty getting back into the car once they return home. These behaviors may seem inconsistent. Whereas in reality, they are often very consistent with pain that varies depending on effort, rest, or fatigue.

“He doesn't listen to anything anymore. ”

A dog who no longer wants to sit, lie down, shake a paw, or get in the car boot has not necessarily decided to ignore you. He may very well have understood what is being asked of him, but no longer wants to perform the movement because he associates it with an unpleasant sensation. The more you insist, the more you risk increasing his discomfort. What looks like disobedience is sometimes simply an avoidance behavior that is perfectly logical for him. That's why a situation or a command that was previously well-established, and then suddenly ignored, always deserves consideration. Is the dog truly ignoring it... or has that movement become too painful for him?

“He comes to see us less.”

This is a subtle but very common change: the dog gets up less easily when we come home, he no longer follows us everywhere in the house, he prefers to stay lying down rather than come for a cuddle or to greet us. Again, it's tempting to see this as a change in character or a decrease in interest. However, in some painful dogs, it's simply an economy of movement. Every movement requires extra effort. So they move less, even when they want to be with us.

“He always licks the same spot.”

Repetitive licking is not always behavioral in origin. When it always concerns the same area, it can also indicate local discomfort: a painful joint, muscle tension, nerve irritation, or other pain that is difficult to identify. Licking is therefore not only a behavior. It can also be a clinical clue (do not hesitate to discuss it with your veterinarian during a consultation).

“He suddenly guards his bed.”

A dog who has never shown resource guarding and suddenly starts growling when approached while on his bed also deserves a medical evaluation. Getting up, changing position, or being touched during rest can become painful. In this context, the bed becomes less an object to defend than a place where the dog simply seeks not to be disturbed. It's not the label of the behavior that matters. It's its appearance, its evolution, and the context in which it occurs. When a behavior changes without obvious explanation, it is always safer to first ask what has physically changed before concluding a training or character problem.

"If he was really hurting, he'd whimper."

This is probably the most common misconception.

We tend to associate pain with very visible signs: whimpering, a noticeable limp, or a dog that completely refuses to move. In dogs, this is far from systematic. The WSAVA recommendations remind us that pain is often expressed by an accumulation of small changes rather than a spectacular sign. A change in posture, reluctance to certain movements, different sleep patterns, unusual irritability, or a decrease in activity are sometimes much more revealing than a whimper.

In other words, the absence of complaint does not mean that a dog is not in pain!

“The vet found nothing, so he's not in pain.”

Again, it's not that simple.

Some pains are intermittent. Others only appear in very specific circumstances. The stress of the consultation can also mask certain signs, as can adrenaline or excitement. Sometimes, pain is difficult to reproduce during a classical clinical examination. This is one of the findings of De Keuster and his team's work: some dogs experience real pain despite an initial unremarkable examination.

This obviously does not mean that all "normal" examinations are wrong. However, when doubt persists, the veterinarian may need to complete their investigations, suggest imaging, or monitor the evolution over time.

“He becomes capricious with age.”

Aging does not make a dog capricious.

However, aging increases the risk of developing chronic pain, particularly in the joints, muscles, or spine. When an older dog gradually changes its behavior, it is therefore more relevant to look for a medical explanation before seeing it as a simple change in character.

“It's only sometimes, so it's really his behavior. ”

It's precisely the opposite that should draw attention.

Pain is often very contextual. The dog refuses the car boot, but not a leisurely walk. The harness triggers a growl, but not petting. Stairs become difficult, while walking on flat ground poses no problem. These situations may seem inconsistent when only considering behavior. One must look at the whole picture and reason in terms of pain and movements involved.

Dogs for whom particular vigilance is required

All dogs can suffer without expressing it clearly.

However, certain profiles present a higher risk.

This is particularly the case for older dogs, large and very large breeds, breeds predisposed to vertebral affections, sports or very active dogs, but also those who have already presented a trauma, surgery or an orthopedic problem.

However, the most important criterion is neither breed nor age. It is change.

A dog who used to do something easily and gradually stops doing it always deserves an inquiry into the reason why.

Whether it's a refusal to jump, an unusual growl, a decrease in activity, or a change in habits, it's the appearance of this change that should draw attention.

When to consult?

When a behavior appears suddenly or gradually changes without obvious explanation, the first step should be medical.

Before talking about training, obedience or character, it is important to check that pain is not hidden behind these changes.

Depending on the situation, the veterinarian may perform a thorough locomotor examination, look for pain during handling, suggest further examinations or, in some cases, implement a therapeutic analgesic trial as part of their diagnostic approach.

The WSAVA recommendations remind us that this trial is one of the tools available to the veterinarian. However, it should not be improvised at home or carried out without follow-up.

Once a painful cause has been reasonably ruled out, behavioral or educational work can then be undertaken under better conditions.

Looking for pain first does not mean explaining everything by pain.

It is simply avoiding asking a dog to make a movement that it may be trying to avoid because it hurts.

Conclusion

We often hear about "stubborn", "capricious" or "bad-tempered" dogs.

Yet, these words describe a behavior. They do not explain its cause. The same behavior can have very different origins. It can be related to training, to an emotion, to a trauma or a past experience but also and above all to pain.

This is why a change in behavior should always be taken seriously, especially when it appears in a dog that did not act like this before.

Before trying to correct the behavior, it is often more useful to ask why it appears.

Dogs do not have the same means of expression as us. They cannot explain that a movement pulls, that an area is sensitive or that handling hurts them. They communicate in other ways: through their posture, their avoidances, their tensions, their refusals, their growls. It is therefore up to us to learn to read this non-verbal language, before too quickly concluding that it is a problem of training or character.

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Sources:

1. Mills DS, Demontigny-Bédard I, Gruen M, et al. Pain and Problem Behavior in Cats and Dogs. Animals. 2020.

2. Kwik J, De Keuster T, et al. Detection of maladaptive pain in dogs referred for behavioral complaints: challenges and opportunities. 2025.

3. Ghasempour M, Ünsal Gündüz HÖ. Dog owners' recognition of pain-related behavioral changes in their dogs. 2023.

4. Malkani R, et al. How does chronic pain impact the lives of dogs? 2024.

5. Monteiro BP, Steagall PVM, Lascelles BDX, et al. 2022 WSAVA Guidelines for the Recognition, Assessment and Treatment of Pain. Journal of Small Animal Practice. 2023.

6. Barcelos A-M, Mills DS, Zulch H. Clinical indicators of occult musculoskeletal pain in aggressive dogs. Veterinary Record. 2015.