Laughter might not be confined or unique to humans, despite Aristotle’s observation that “only the human animal laughs”. The differences between chimpanzee and human laughter may be the result of adaptations that have evolved to enable human speech. However, some behavioural psychologists argue that self-awareness of one’s situation, or the ability to identify with somebody else’s predicament, are prerequisites for laughter, so animals are not really laughing in the same way that we do.

The dog-laugh sounds similar to a normal pant. However by analyzing the pant using a spectrograph, this pant varies with bursts of frequencies, resulting in a laugh. When this recorded dog-laugh vocalization is played to dogs in a shelter setting, it can initiate play, promote pro-social behavior, and decrease stress levels. In a study by Simonet, Versteeg, and Storie, one hundred and twenty subject dogs residing in a mid-size county animal shelter were observed. Dogs ranging from 4 months to 10 years of age were compared with and without exposure to a dog-laugh recording. The stress behaviors measured included panting, growling, salivating, pacing, barking, cowering, lunging, play-bows, sitting, orienting and lying down. The study resulted in positive findings when exposed to the dog laughing resulted in the following: significantly reduced stress behaviors, increased tail wagging and the display of a play-face when playing was initiated, and the increase of pro-social behavior such as approaching and lip licking were more frequent. This research suggests exposure to dog-laugh vocalizations can calm and possibly increase shelter adoptions.