As someone who is lucky enough to have a gorgeous cavapoo, Bodhi, in my life, I can absolutely vouch for the immeasurable benefits dogs can make to our wellbeing. I named him after the Bodhi tree which, according to Buddhist tradition, was the sacred fig tree Buddha sat under when he attained Enlightenment. I did this in the hope that he would bring me more into the present moment and give me the balance I was looking for in life. And I can safely and gratefully say that he has done just that and much, much more.
There’s no doubt many other dog owners will share similar sentiments, but you may not know that there is a significant body of scientific work that backs up what many of us have experienced for ourselves.
It’s well documented that dogs have an amazing sense of smell, but a recent study carried out at Queen's University Belfast found that they can actually sense when we are stressed by detecting chemical changes in our breath and sweat. And with extraordinary accuracy.
The researchers obtained samples of sweat or breath from participants before and after they had them complete a maths problem. They also recorded the participants’ heart rates and blood pressure and had them self-report their stress levels before and after.
The before and after samples of particularly stressed participants were then presented to dogs who had been previously trained rewarded with treats after correctly matching smells.
On average, the dogs could pick out the stress sample 93.75 per cent of the time, with the best performer getting it right an incredible 96.88 per cent of the time.
We all know by experience that our dogs seem to be able to tell when we are stressed, but how do they achieve this extraordinary accuracy? The researchers think that it may be the change of smell associated with the volatile organic compounds, or VOCs, that we produce when we are stressed.
Hundreds of VOCs are emitted from our bodies and can reflect the metabolic state we are in at that time. Body odour is a result of a combination of these and typical sources include our breath, sweat, skin, urine and faeces.
When we experience stress, our autonomic nervous system triggers our hypothalamus to send hormonal signals to the pituitary gland and the adrenal glands. The release of stress hormones like cortisol and adrenaline causes an increase in heart rate, increased sweat, decreased salivary flow and increased blood supply.
This cascade of hormones is associated with stress, and the changes in our metabolic state has a knock-on impact on our breath and sweat and the VOC components in these. Perhaps this is why our dogs seem to be able to notice and offer support when we are experiencing mental health challenges like panic attacks, post-traumatic stress disorder and anxiety.
But what is going on in our bodies and brains that makes our bond with our pet pooches so special?
One theory says that the calming, therapeutic effect our pet dogs have on us is due to social recognition - the mechanism by which we identify someone as being important and significant to us. This is the basis of our ability to form meaningful social connections and relationships - a fundamental component of maintaining good mental health.
We have evolved to look after, protect and care for those we have made social bonds with. We recognise our pet dogs to be 'ours' and someone we have made a social connection with. This can trigger a similar brain bonding network to a maternal one. This mechanism could find its basis in oxytocin - a hormone that has a key role in maternal bonding, lactation and is a chemical messenger involved in recognition and trust.
One study carried out at Massachusetts General Hospital involved women looking at pictures of their child and their pet dog, and using functional MRI showed similar responses in area of the brain related to reward and emotion and bonding.They found that the pictures of their dogs triggered similar brain responses in mothers' brains to pictures of their children. Areas of the brain known to be important for functions such as emotion, reward, affiliation, visual processing, and social interaction all showed increased activity when participants viewed either their own child or their own dog. It seems we really do love our dogs like we love our children.
Of course, there are some things about our relationships with our canine companions that we likely won’t ever be able to measure objectively or scientifically. But whenever Bodhi greets me, tail wagging enthusiastically, when I get home after a long day’s work, I know our bond is a special one.
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