The effects of green odour on domestic dogs: A pilot study

Green odour (a mixture of cis-3-hexenol and trans-2-hexenal), similar to cut grass, has been demonstrated to appease subjects of various species (rats, cattle, humans etc.) subjected to different stressful stimuli. The aim of this study was to investigate whether green odour has a calming effect also on the domestic dog. Sixteen companion dogs participated in the study with their owners. Each dog was tested through a simplified version of the Ainsworth Strange Situation Test. Dogs acted as their own control, being tested three weeks apart in an experimental room once with the green odour and once without it. Saliva samples were collected, for both conditions, before the test and 20 min after separation in order to measure cortisol levels. The presence of green odour in the experimental room did not affect dog behaviour during separation from the owner. In addition, deltas of salivary cortisol levels in the two tests did not differ. However, differences in dog behaviour were observed when the owner was present, both before and after separation, indicating that, when tested in the presence of green odour, dogs sat more and spent less time in proximity to the owner. When tested without the green odour, dogs instead sought more contact with the owner. These findings suggest that green odour has a light stress-alleviating effect, which appears in more relaxed behaviour in the presence of the owner.