If you’re a dog owner, you’ve likely noticed that when you pet or scratch your furry friend, they have a tendency to close their eyes and relax into your touch. This sweet gesture is a sign that your pup is enjoying the affection and finds it soothing.

But have you ever wondered why dogs close their eyes when petted? There’s actually some fascinating science behind this phenomenon.

If you’re short on time, here’s a quick answer to your question: Dogs close their eyes when petted due to the release of oxytocin, a hormone associated with bonding, pleasure, and trust. The act of petting triggers oxytocin production in both the dog and the human, facilitating social attachment and contentment.

Oxytocin Release

Oxytocin’s Role in Social Bonding

Oxytocin, sometimes referred to as the “love hormone,” is a neuropeptide that plays a crucial role in social bonding and affiliation in mammals. When oxytocin is released in the brain, it promotes trust, reduces fear, and induces feelings of contentment.

Studies show that oxytocin facilitates bonding between mothers and infants, romantic partners, and even human-animal relationships.

In dogs, oxytocin levels have been found to increase after friendly interactions with human owners. Petting, cuddling, eye contact, and vocalizations like baby talk can all cause a surge of oxytocin in dogs. This reinforces the social bond between dog and human.

Oxytocin Release in Both Dog and Human During Petting

Research has confirmed that when a human pets a dog, oxytocin levels increase in both the dog’s and human’s brains. In a 2009 study, researchers measured oxytocin levels in dogs before and after interactions with their owners.

Oxytocin levels increased in both the dogs and owners after as little as 10 minutes of petting. The longer the interaction, the more oxytocin was released.

Higher oxytocin levels corresponded with dogs gazing more at their owners, as well as owners reporting greater feelings of bonding with their dogs. This shows that oxytocin reinforces human-animal bonds similarly to human-infant bonds.

Relaxation Response

In addition to oxytocin release, petting a dog can induce a relaxation response. Gentle stroking helps lower blood pressure and cortisol levels in dogs. Cortisol is a hormone associated with stress.

At the same time, petting increases production of serotonin, dopamine, and endogenous opioids in dogs’ brains. These neurotransmitters and hormones boost mood and provide pain relief. The rise in oxytocin also promotes relaxation.

This combination of effects explains why dogs often appear peaceful and content when being stroked by their owners. Their half-closed eyes indicate calmness and enjoyment of the tactile stimulation.In fact, in a 2016 study, shelter dogs that received just 5-8 minutes of petting every day for 2 weeks showed less stress behaviors and lower cortisol levels. So when you see your pup happily melting under your gentle pets, it means the bonding and relaxation response is working!

Tactile Stimulation

Nerve Endings in Dog’s Skin

A dog’s skin contains an abundance of nerve endings, even more than humans in some areas like behind their ears. These nerves allow dogs to feel subtle sensations on their fur and skin. Light touches from petting stimulate these nerves in an enjoyable way for dogs, releasing feel-good chemicals like oxytocin in their brains.

The high density of nerves is why dogs are so sensitive to tactile stimulation.

Feels Good!

Being pet causes the release of serotonin and dopamine in a dog’s brain, hormones associated with pleasure and contentment. As most dog owners can attest, dogs really enjoy and even crave this positive tactile stimulation.

When petted, dogs often lean into the touch and move towards the hand doing the petting. Their tails may wag happily and their mouths relax into an open smile. These are all signs demonstrating just how good petting makes dogs feel.

Mimics Mother’s Tongue Grooming

Research has shown that a major reason petting feels good to dogs traces back to their early days as puppies. A mother dog’s licking and grooming stimulates nerve endings on puppies’ skin and releases feel-good hormones, forging a bond and sense of comfort.

Later in life as adult dogs, the actions involved in petting mimic the sensations of being groomed by their mother. So petting may subconsciously take adult dogs back to their soothing puppyhood experiences.

Element A Dog’s Experience When Petted
Nerve stimulation Pleasurable nerve signals released to brain
Hormone release Dopamine, serotonin, oxytocin flood their system
Associated behaviors Leaning into touch, mouth smiles, tail wagging
Puppyhood memory Subconsciously reminds them of their mother’s affectionate grooming

Show of Trust

Exposing Vulnerable Areas

When a dog closes its eyes during petting, it is exposing some of its most vulnerable body parts to the human’s touch, demonstrating great trust. The head houses vital sensory organs for the dog, so presenting it requires confidence that no harm will come.

Allowing the delicate eyes, nose, ears, and throat to be so easily accessed shows that the dog feels completely at ease and safe with its caretaker.

Non-Threatening Social Engagement

Dogs also often close their eyes during petting because it is a positive, non-threatening social interaction for them. The loving touch releases oxytocin, prolactin, and endorphins in both human and dog for pleasurable bonding.

With eyes closed, the dog can relax into enjoying the friendly engagement without feeling the need for any vigilance against danger. This again displays the deep-seated trust and comfort the dog has with the human providing affectionate pets.

Strengthens the Bond

When a dog exposes its vulnerabilities by closing its eyes for petting, it strengthens the attachment and caretaking bond with the human. This potent display of trust in the human allows an even closer relationship to form through the intimacy of gentle touch.

According to the American Kennel Club[1], nearly 90% of dog owners feel more bonded to their pets after sharing in sessions of petting and stroking. So by trusting its human enough to close its eyes and relax into petting, a dog enables greater friendship, loyalty, and compatibility.

Other Explanations

Blocking Out Visual Stimuli

One theory is that dogs close their eyes when being petted as a way to block out visual stimuli so they can focus on the pleasant tactile sensation. By closing their eyes, dogs narrow their focus to the feeling of being petted, which aids relaxation.

This may be similar to when humans close their eyes during a massage. Visual stimuli can be overstimulating for dogs, so blocking it out helps them fully enjoy being petted.

Submission Signal

Closing their eyes when being petted may also be a signal of submission or trust in their human. Dogs that are more submissive may close their eyes to communicate to the human that they accept the contact and are not threatened. It shows that they feel safe and comfortable.

This is likely an innate behavior stemming from evolution when less dominant wolves and wild dogs would avoid eye contact and bare their bellies or necks to more dominant members of the pack. That submissive body language seems to still manifest in our domestic dogs today.

Pure Enjoyment

The most straightforward theory is that dogs simply close their eyes in pure enjoyment while being petted. The tactile stimulation of petting combined with the bond between dog and human is relaxing and pleasurable for dogs. Closing their eyes helps them soak up that feeling.

It’s similar to when people close their eyes to soak in the warmth of the sun. Dogs want to fully immerse themselves in that loving sensation. And it sure looks like they’re in bliss when they close their eyes and lean into a good petting session!

So in many cases, it may simply be an expression of total contentment.


In summary, dogs tend to close their eyes when being petted due to a combination of factors. The stroking motion releases oxytocin, providing pleasurable sensations. It activates nerve endings in the dog’s skin and mimics the soothing effect of a mother’s tongue grooming.

Closing their eyes also represents a show of trust and a lack of threat between pet and owner. While the exact evolutionary origins require more research, what’s certain is that this endearing behavior reveals the deep social bond between humans and their canine companions.

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