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Key points
- A Czech study tested whether 53 dog owners could pick their own dog’s smell out of a lineup.
- Almost three quarters of participants correctly identified their dog's scent.
- Owners were more likely to recognize dogs that were housed outdoors, bathed less often, and fed dry food.
She curls up in your old sweater for comfort while you’re at work and could find her way home if she got lost by following her nose. With a sense of smell 10,000 to 100,000 times stronger than a human being’s, a dog can easily tell her owner’s scent apart from any other person’s.
Surprisingly, despite our much less sensitive sniffers, dog owners also have the ability to identify their pets by smell alone.
Researchers at the Czech University of Life Sciences in Prague tested 53 dog owners between the ages of 3 and 72 to find out whether they could pick their dog’s smell out of a lineup.
The owners were presented with six glass jars, one containing a gauze pad suffused with their own dog’s scent and five containing the scents of other dogs. Each animal’s scent had been collected by placing the gauze pad under their collar for an hour.
Participants were allowed to sniff the jars for as long as they wanted before choosing which they thought was their dog. To keep from influencing the results, the experimenters didn’t know which of the jars contained the right sample and stayed in a separate room while the participants were making their choice. Afterwards, the researchers looked up the number code on the chosen jar to find out whether the participant had guessed correctly.
Almost three quarters (71.43%) of the study’s participants were able to accurately identify their dog.
Some surprising factors contributed to the pets’ recognizability. Owners were more likely to know dogs that were housed outdoors, bathed less often, and fed dry food.
The role of baths isn’t difficult to imagine: the less a dog is bathed, the stronger its natural scent will be and the more opportunity its owner will have had to become familiar with the smell.
The researchers had a harder time explaining why living outdoors would make a dog more recognizable than living indoors. They speculated that people who keep their dogs indoors might become “noseblind” to their dog’s smell, so familiar with it they no longer notice it. On the other hand, prolonged exposure to an odor normally makes that scent easier, not harder, to identify. If dogs that have less frequent baths are easier to recognize because their owners have had more contact with their scent, why wouldn’t the same be true for dogs kept indoors?
The study’s authors guessed that owners may have an easier time recognizing dry-fed dogs because they prefer their scent to animals that are fed raw meat. Previous research has shown that women in particular are more partial to the smell of men who eat plant-based, rather than meat-heavy, diets. Owners may be quicker to identify scents they enjoy, and how much we like the way a dog smells may depend on the amount of meat in its diet.
Age and gender also contributed to participants’ ability to recognize their dogs. The younger the dog owner, the better they were at singling out their own pooches. This result is in line with the evidence that sense of smell declines as we age (though it can be improved).
Contrary to expectations, since women typically outperform men on every type of scent task, men had a higher success rate identifying their dogs (89.47%) than their female counterparts (64.71%). The researchers pointed out, though, that this could be because about twice as many women participated in the study as men, giving the women more opportunities to fail.
This study shows that the human sense of smell is keener than we usually give it credit for. Smell may be weaker than many of our other senses, but it still plays a significant role in our social interactions, emotional perceptions, and stress responses.
As for you cat lovers, do you have the same chances of recognizing your feline companion by their smell? Not according to a 2002 study showing cat owners performed no better than chance when trying to identify their pet’s scent. But you can take comfort in the fact that researchers chalked the low success rate up to cats’ better grooming habits.
