Home Dog Science Research Shows Dogs Have Their Favorite Scent – It’s the Owner’s Smell

Research Shows Dogs Have Their Favorite Scent – It’s the Owner’s Smell

Research Shows Dogs Have Their Favorite Scent – It’s the Owner’s Smell
Scientists found that dogs experience the feelings of pleasure that in the dog's brain is associated with the owner's scent.

A dog's love for its owner is not hard to figure out given how these animals are so devoted and loyal. But according to a study, a dog's brain activity actually spikes and goes crazy when he smells his human. It’s as if this particular odor is a love potion that makes a dog feel the happiest being alive.

Experts at the Emory University in Atlanta studied the way dogs draw pleasure from their owner’s scent. Study leader Gregory Berns and his team looked into the dogs' brainwaves via a functional magnetic resonance imaging (fMRI) to find proof on just how deeply attached dogs are from their owners. Berns and his team published their findings in the Behavioural Process journal.

Most Activated By The Human Smell

The researchers tested 12 pets, five therapy dogs, and Callie, Berns' own dog. The canines were prodded to smell different pads that had five scents each, as the researchers tested their brains' responses via the fMRI.

Participants of the study.
Participants of the study. Berns et al.

These scents consisted of their human owner, the dog's, another dog that lives in the same house, an unfamiliar human and an unfamiliar dog. Though it was uncomfortable, the researchers also asked their humans not to bathe nor use deodorant for 24 hours before being swabbed.

Following the fMRI tests, the scientists learned that an area in the dogs' brain called the caudate nucleus showed a lot of activity when the canines smelled something familiar. It indicated two things: that the dogs could not only pick out their owner's scent, but this particular scent has been retained in their memory.

Berns noted that none of the dogs' owners were physically present during the experiment. Yet the canines' brain response to their scent was a lot similar to when they see their humans come home, where these dogs excitedly jump, kiss and lick their owners.

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The Reward Response

The experts said that the dogs presented fewer brain activities for the four other scents. The smell of a familiar dog, however, triggered something too, but it wasn't as distinct as their response to their owner.

Dog's brain response to different smells
Whole-brain group analysis of differential response to familiar and strange scents. Berns et al.

So, while the dogs showed they were attuned to the smell of the familiar dog, their highly enthusiastic brain waves for their humans could be because of what the experts call the reward response. In short, the dogs associated their owner’s smell to something positive — be it food, or playtime, or simply their human’s general disposition towards them.

Berns even went further to explain that this effect could be similar to how humans react when they smell their loved one's perfume or cologne. A man can go crazy and get turned on with just a whiff of his girlfriend’s scent, and dogs apparently derive the same type of pleasure.

Sniffing Which Dogs Can Be Therapy Dogs

Meanwhile, the study also differentiated the responses of therapy dogs from the rest of the participants. Apparently, they had the most positive reactions to their human's scent and the experts said that this might be because they are highly trained to interact with humans.

Berns, however, suggested that if therapy dogs’ are further scanned for specific brain responses then their owners or handlers might be able to figure out what their most effective roles can be.

Currently, only 30 to 40 percent of therapy dogs are placed into service since training working dogs can cost a lot. Given what they know now, then these working dogs could be further trained to focus on a specialized task so that they become more helpful and successful as service dogs.

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Sam has a Master's degree in Engineering Physics and years of experience in writing science reports, scientific research and science content. Being very passionate about animals, he's always looking for opportunities to use his skills and experience in researching and writing about dogs.