Why you love your dog

The pair bond between dogs and their owners is strengthened by the hormone oxytocin.  Photo courtesy of Christopher D. Wells.

Have you ever had the feeling that your pet was your best friend or like a child to you?  Turns out, that’s normal!  Interactions between you and your pet have real, measurable positive effects on the health of both you and your dog.  Studies show that when you interact with your dog, a hormone called oxytocin is released into your bloodstream.  Oxytocin is frequently referred to as the "trust" or "love" hormone.

Oxytocin was first discovered in 1906 as a hormone that increases during and after child birth, and secures a bond between the mother and her newborn.  More recent studies have investigated the role of oxytocin in behaviors such as social recognition, anxiety, and pair-bonding.  The same connection that is formed between mother and child is formed between you and Sparky (chemically speaking).  This is why you may identify and love them as if they were your baby. 

Oxytocin: the "love" and "trust" hormone.   Oxytocin is a peptide of nine amino acids.  Photo courtesy of wikimedia.org.

Oxytocin: the "love" and "trust" hormone.   Oxytocin is a peptide of nine amino acids.  Photo courtesy of wikimedia.org.

Oxytocin is released during various positive sensory stimulations such as touch, light pressure, warmth, and stroking as well as by olfactory (smell), auditory (sound), and visual cues.  This is why Sparky loves his belly rubs!  Massage, skin-to-skin contact between mothers and infants, and suckling during breastfeeding all increase human oxytocin levels.

Short-term increased levels of oxytocin have been shown to decrease cortisol and adrenaline levels (stress and anxiety hormones), lower blood pressure, and reduce pulse rate.  Repeated exposure to oxytocin may increase pain threshold and decrease energy expenditure (leading to weight gain).  Newborn rats exposed to high levels of maternal affection displayed reduced fear, increased social interactions, and had more oxytocin receptors (where hormones bind to a cell to affect the cell) as adults.

One set of researchers from Sweden quantified the short-term benefit of interaction between people and dogs (Handlin et al., 2011).  Blood was drawn from 10 women with dogs and 10 women without dogs at the start and after 3 minutes of petting and talking with their dogs.  Simultaneously, blood was drawn from the dogs.  Blood was tested for both oxytocin and cortisol.  Oxytocin increased in both the women and the dogs during the rub-down, but quickly dissipated.  Cortisol (a stress hormone) decreased in the women after interacting with the dogs, but increased in the dogs.

Oxytocin can have a sedative effect putting you and your pet to sleep.  Photo courtesy of ratforum.com. 

Another study found that just staring at your dog was enough to increase oxytocin levels to detectable levels in your urine (Nagasawa et al., 2009)!

This is all in addition to other benefits of owning a dog.  Pet ownership provides many benefits such as increased physical exercise, greater social interactions, decreased depression and loneliness.  Get (adopt) a dog; you just might fall in love!

Thanks for reading.  If you like what you see or have any questions leave a comment below.  Don’t forget to subscribe to our blog!  Stay hungry. 


Handlin, L., Hydbring-Sandberg, E., Nilsson, A., Ejdeback, M., Jansson, A., and Ulvnäs-Moberg, K. 2011. Short-term interaction between dogs and their owners: effects on oxytocin, cortisol, insulin and heart rate - an exploratory study. Anthrozoös 24: 301-315.

Nagasawa, M., Kikusui, T., Onaka, T., and Ohta, M. 2009. Dog's gaze at its owner increases owner's urinary oxytocin during social interaction. Hormones and Behavior 55: 434-441.