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As any dog owner will tell you, their canine <\/span>friend can tell when they are feeling stressed. Now, researchers at Queen\u2019s University Belfast have demonstrated that <\/span>they\u2019re right: dogs <\/span>do <\/em>know when we\u2019re stressed, because they can smell it.<\/span><\/p>\n\n The finding follows previous studies on the canine sense of smell, which have shown that dogs are able to sniff out cancer and COVID-19 in human sweat. <\/p>\n\n To make this latest discovery, the team recruited four dogs \u2013 Treo, Fingal, Soot and Winnie \u2013 from domestic homes in Belfast, along with 36 human volunteers. They set the humans a complicated maths problem designed to raise their stress levels and took samples of their sweat and breath before and after they attempted to solve it. The researchers monitored the volunteers throughout the experiment and only took the second sample when they detected increases in their blood pressure and heart rate \u2013 both clear indicators of stress. <\/p>\n\n Meanwhile, the dogs were trained to pick out specific scents from a line-up. <\/p>\n\n The team then presented each of the dogs with a selection of scents, including a volunteer\u2019s relaxed and stressed samples, to see if the dogs could distinguish between them. All four of the dogs were able to correctly identify each volunteer\u2019s stressed sample, even though they had never met them before. <\/p>\n\n \u201cThe findings show that humans produce different smells through our sweat and breath when we\u2019re stressed and dogs can tell these apart from our smell when relaxed \u2013 even if it\u2019s someone they don\u2019t know,\u201d said researcher Clara Wilson, a PhD student in the school of psychology at Queen\u2019s University. <\/p>\n\n \u201cThe research highlights that dogs don\u2019t need visual or audio cues to pick up on human stress. This is the first study of its kind and it provides evidence that dogs can smell stress from breath and sweat alone, which could be useful when training service and therapy dogs. <\/p>\n\n \u201cIt also helps to shed more light on the human-dog relationship and adds to our understanding of how dogs may interpret and interact with human psychological states.\u201d <\/p>\n\n Dogs are famous for their incredible sense of smell. Here are just a few of the factors that make their noses so sensitive\u2026 <\/strong><\/p>\n\n Each of a dog\u2019s nostrils is able to smell independently. This allows them to determine which direction a particular scent is coming from. <\/p>\n\n Our canine companions have around 220 million scent receptors in their noses. Humans have just five million. <\/p>\n\n With so many more receptors in their noses, a dog\u2019s sense of smell is around 10,000 times more sensitive than a human\u2019s. <\/p>\n\n
\n\nSCENTS AND SENSE-ABILITY <\/h4>\n\n
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<\/figure><\/div>\n\nSMELLING IN STEREO <\/h5>\n\n
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<\/figure><\/div>\n\nA NUMBERS GAME <\/h5>\n\n
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<\/figure><\/div>\n\nSENSITIVE TO SCENTS <\/h5>\n\n