It is often said that a dog is man's best friend. That closeness between man and dog is, in part, down to oxytocin. Also known as the 'love' or 'feel-good' hormone, it is made in the brain and released into the bloodstream. As well as having a number of physiological jobs to do (such as inducing womb contraction in labor, or milk let-down when breast-feeding), oxytocin also promotes bonding between mother and baby - or in this case man and dog.
So how is this? Do dogs smell oxytocin or is there some other mechanism involved?
Actually, the answer isn't straightforward.
With a dog's supremely sensitive sense of smell it's highly likely they can detect oxytocin, however, this is almost unimportant when looking at the amazing role of oxytocin and how it bonds owner to dog or dog to owner.
Signs a Dog can Smell Oxytocin
It is a fact that oxytocin is responsible for the amazing bond between man and dog. However, it isn't so much that the dog smells oxytocin, more that they produce their own oxytocin in response to seeing a beloved pet parent. The opposite is also true, when an owner gazes on their fur-friend or gently strokes their head, this raises the owner's level of oxytocin. Since oxytocin's job is to bond mother to baby, the end result is strengthening the warm feelings between dog and owner, and vice versa.
What's arguably even more interesting is that some dogs have more internal receptors for oxytocin, and are therefore more likely to be loyal and affectionate to their owner. Whilst the other side of the coin is that some dogs have an appearance that is more childlike (think of those flat-faced pugs) and able to generate more oxytocin in the viewer (their owner). Indeed, this in part accounts for the popularity of many top ten dog breeds, in that their physical appearance makes them more attractive to people on account of oxytocin release.
And if you're looking for signs that your dog is under the influence of oxytocin, then consider how loving and loyal they are. An affectionate, loving dog is highly likely to have a generous amount of oxytocin in their bloodstream.
History of Dogs and Oxytocin
It's interesting to note that it isn't just pet dogs that like humans - stray dogs do too. They often choose to hang around where people live, and that isn't just because we leave food scraps out. There's something unique about the relationship between man and dog, and guess what - it's down to oxytocin.
It seems man and dog have the ability to mutually raise each others' oxytocin levels. And when oxytocin means feeling good, this is one heck of a talent to have. Going way back to the first domesticated dogs, it seems likely that at first they hung around the cavemen's fires for warmth and scraps, but it was the mutual bond of oxytocin that created something deeper than mere convenience.
As time rolled on and dogs became better adapted to living with people, people started selectively breeding their canine companions. At first this was to create the ultimate guarding or hunting dog, but latterly dogs with a more human or baby-like face were favored.
Again, it's not so much that dogs can smell oxytocin, but that their bodies respond to human company by producing more of it. With the same being true for people, you could say it's a match made in heaven!
The Science of Dogs and Oxytocin
Technically, yes a dog may be able to pick up the scent of oxytocin on a person's sweat or clothing. However, smelling the oxytocin is the equivalent of registering it's presence but without affecting the body. To make a difference to the way the dog feels, it is the oxytocin produced in their own brain that will do this.
When released, this oxytocin binds with receptors that turn on that feel good feeling.
Think of the oxytocin as a key and the receptor as a lock. To get the bonded feeling, the key needs to be inserted in the lock and turned. When a dog sniffs oxytocin, they are 'seeing' the key, but it isn't physically in a place where it can activate the lock.
When a dog sees someone they love (their pet parent) and that person then praises them and stares into their eyes, this releases a surge of feel-good oxytocin. In that wonderful way of the connection of things, this also accounts for why reward-based training works so well. By praising the good, you build their self-confidence and raise levels of oxytocin, helping them feel good about themself. Why would they then not want to be obedient, and get a high from those natural hormones?
Another interesting fact is that scientists have looked at the numbers and types of oxytocin receptors different dog breeds have. Not all are created equal. Researchers compared German Shepherds with Border Collies and found they had different types of receptors, the numbers of which varied between dogs, and there was a strong link between how friendly the dog was to strangers, and the presence of a certain type of oxytocin receptor.
Training a Dog to Smell Oxytocin
Training a dog to smell oxytocin would be done in a similar way to training a sniffer dog. It requires a sample of oxytocin and then rewarding the dog when they locate the object covered in oxytocin. However, it is questionable how useful this is to teach. After all, if someone is high on oxytocin, there are easier ways to detect it - such as by the person's soft, loved-up smile.
What is arguably more beneficial for dog and humankind alike, is to be kind to one another and praise each other's achievement. With gentle touch and loving attitudes, this is a natural way to induce oxytocin release in both man and dog, and let's face it, spreading happiness is something the world could do with a lot of right now.
By Pippa Elliott
Published: 04/22/2018, edited: 04/06/2020