Can Your Dog Tell When You’re Stressed?

I notice this a lot with my own dog. Some days she is completely settled, while on others she seems more alert, more watchful or a little more inclined to stick close to me. Sometimes there is an obvious reason for it. Something has happened outside, we’ve had a change in routine, or she’s simply having a more difficult day. Other times I can look around and struggle to find anything that has changed.

It took me a while to start including myself in that assessment.

Sabai is a nervous dog anyway, so I’m used to paying close attention to her environment. I notice other dogs approaching, unusual noises, unfamiliar people and all the other things that might make the world feel slightly less predictable to her. What is much easier to overlook is that I’m part of her environment too.

Dogs spend an extraordinary amount of time around us. They watch how we move, listen to our voices and live amongst all the tiny changes in our behaviour that accompany different moods. Increasingly, research suggests there is another source of information available to them as well: they may actually be able to smell when we’re stressed.

Dogs can smell human stress

In 2024, researchers from the University of Bristol investigated what happened when dogs were exposed to odour samples taken from people experiencing stress or relaxation.

The clever part was removing the person from the experiment altogether. Sweat and breath samples were collected from human volunteers and later presented to dogs participating in a cognitive-bias test. The odours came from unfamiliar people, so the dogs weren’t responding to someone they knew behaving differently.

The researchers had previously trained the dogs to understand that a bowl in one location contained food while a bowl in another did not. They could then place bowls in ambiguous positions between the two and measure how readily the dogs approached them. This type of experiment is used in animal-welfare research to investigate how an animal’s emotional state may affect the way it responds to uncertainty.

When exposed to human stress odour, the dogs were less likely to approach the bowl at one of the ambiguous locations than when no odour was present. The researchers interpreted this as possible risk-reduction behaviour: the smell of human stress appeared to make the dogs more cautious about an uncertain outcome.  

There are limitations. Only 18 dogs completed the relevant testing, and the effect appeared at one of the three ambiguous bowl locations and was influenced by testing order. It doesn’t prove that every time you’re stressed, your dog becomes stressed too.

What it does show is rather remarkable on its own. A dog can receive information about human stress without needing to see our face or hear our voice.

They’re getting information from more than smell

Of course, our dogs rarely encounter our scent in isolation. At home they get the whole person.

Our voices can change when we’re under pressure. We may move differently, become less patient, breathe differently, rush around the house or interact with our dogs in subtly different ways. Dogs have been living alongside humans for thousands of years and there is substantial evidence that they use human social information, including gaze, gestures, facial expressions and vocal cues.  

That makes the idea that they “know” we’re stressed simultaneously more complicated and more interesting. They don’t need to understand that you’ve had a terrible meeting, you’re worrying about money or you’ve got far too much to do. Those are human stories. What is available to the dog is the change in the person standing in front of them.

For a sensitive dog, those small differences may be particularly relevant. If the person they use as a source of information about the world suddenly sounds different, moves differently or even smells different, it isn’t difficult to see why that information might matter.

Can our stress become their stress?

This is where it’s worth being careful with language. “Dogs absorb our stress” makes a very good social-media headline, but the relationship between two animals living together is unlikely to be quite that simple.

There is some intriguing evidence of stress synchronisation between dogs and their owners. In a 2019 study, researchers measured cortisol in the hair of 58 dogs and their owners. Unlike a saliva sample, which can tell researchers about cortisol over a much shorter period, hair can provide information about longer-term hormone levels.

The researchers found that the dogs’ and owners’ hair cortisol concentrations were correlated during measurements reflecting both summer and winter. Dog activity levels and the amount of training they did didn’t explain the relationship, and characteristics of the owner appeared to have more influence on the dog’s cortisol than the other way around.  

It is fascinating research, but it was a fairly specific group: Border Collies and Shetland Sheepdogs living with female owners. Shared lives also mean shared environments, routines and experiences, which makes relationships like these difficult to reduce to a simple case of one individual’s stress transferring directly into another.

Still, alongside the experimental work on stress odour, it adds to a growing picture of dogs as animals that are extraordinarily attentive to the humans they live with.

That doesn’t mean your dog’s behaviour is about you

This distinction matters, particularly for people living with anxious or reactive dogs.

If your dog is having a difficult day, your stress shouldn’t automatically become the explanation. Restlessness, clinginess, increased vigilance or reactivity can have many causes. Something in the environment may have changed without you noticing it. Your dog may be tired, uncomfortable or unwell. They may have experienced something earlier in the day that you’re unaware of. Sometimes dogs simply behave differently and we never discover exactly why.

There is also an uncomfortable implication in telling people that their anxiety makes their dog anxious: that if only the human could calm down, the dog’s behaviour would disappear. The evidence doesn’t justify that, and it’s particularly unhelpful when somebody is already managing a dog with behavioural difficulties.

Your emotional state is better thought of as one part of the environment your dog is responding to, not the explanation for everything they do.

For me, that’s actually a much more useful way to think about it. If Sabai is unusually on edge, I can still consider the dog she passed earlier, the noise outside, how much sleep she’s had and everything else I would normally notice. I can just include myself on that list.

Do you need to calm yourself down for your dog?

You don’t need to spend your life performing serenity.

Dogs live with real humans. We get annoyed, rush around, have terrible days and occasionally swear at inanimate objects. The fact that our dogs may detect some of those changes doesn’t mean ordinary human emotion is harmful to them.

Where this research can be useful is in moments when a dog is already finding something difficult. If you’re holding the lead tightly, moving quickly, repeatedly anticipating something going wrong or becoming increasingly tense yourself, your dog has access to some of that information. Slowing down, giving them more distance or taking a moment before continuing may help change the situation you’re both in.

I’d be more cautious about the carousel’s 4-7-8 breathing exercise. Slow breathing may help you regulate your own arousal, but I wouldn’t tell readers that a particular breathing sequence or audible sigh will make their dog “feel the shift too”. The research doesn’t establish that, and we don’t need the claim for the article to work.

What I find much more interesting is simply knowing how much information may be passing between us without either species deliberately communicating anything.

I’ve spent years learning to read my nervous dog. All that time, she’s been reading me too.