Dogs are, for the most part, our best friends — many of us have given in to the temptation of petting a stranger's adorable, trusting dog as it passed us on our evening walk.
In most cases, nothing other than a moment of delight with a friendly animal takes place.
Sometimes, however, dogs have been known to turn from friend to foe and suddenly snap and bite at a hand outstretched to pat.
But the reasons behind why dogs that may otherwise seem affectionate and approachable become aggressive are not always straightforward. And, researchers don't have much to go on to try to understand why humans' most loyal companion unexpectedly becomes aggressive at times.
Usually, data rely on information provided by individuals who have already been bitten, and they may only offer an incomplete or unreliable account of the encounter.
But recently, investigators from the University of Liverpool in the United Kingdom have turned to an unexpected source of information that, they hope, may offer a better perspective on the context in which biting takes place: YouTube videos.
"Online videos present us with an unexplored opportunity to observe dog bites first-hand, something which is just not possible using other methods," says lead study author Sara Owczarczak-Garstecka, adding:
"Making more use of this type of shared content for research could help us better understand how and why bites occur and contribute to the development of bite prevention strategies."
The researchers' findings were published in the journal Scientific Reports.
Children and infants get bitten more often
The scientists' methodology was fairly simple: they used telling keywords, including "dog bite" and "dog attack," to search YouTube for videos depicting individuals getting bitten by dogs.
Owczarczak-Garstecka and team ended up analyzing 143 clips — showing 362 bites — uploaded to the popular website between January 2016 and March 2017.
In each case, the researchers assessed the context in which the dog ended up biting a person, the severity of the bite, who got bitten, and what breed the dog pertained to.
In 56 of the clips, the researchers were also able to ascertain what behavior both humans and dogs exhibited prior to the bite.
Owczarczak-Garstecka and team found that, of the dog breeds often chosen as pets, it was mostly Chihuahuas, German Shepherds, pit bulls, and Labrador Retrievers that appeared to do the biting. Yet, more often than not, the "offenders" were cross-breed dogs.
About 7 in 10 of the people who got bitten were male, and in more than half of the situations, the victims were children or infants.
The researchers warn that due to the relatively small number of video samples that they analyzed, they were unable to establish clear relationships of causality between certain types of human behavior and instances of aggression in dogs.
However, they did note that in many cases, "tactile contact with a dog" became more insistent 21 seconds before the biting, and that individuals getting bitten often stood or leant over the dog.
Still, Owczarczak-Garstecka and team admit that they struggled with some limitations — especially the fact that YouTube videos may be biased.
Users, the researchers surmised, may be more likely to upload videos in which small dogs, such as Chihuahuas, do the biting, as these may be perceived as funnier and more likely to attract a larger number of viewers.
The researchers' next step from here will be to study the behavior of people who interact with dogs in greater depth, as well as their perception of dog bites and when they take place.
In order to do so, they plan to interview dog owners, people who work with dogs, and those who have previously been bitten.
"[The] findings," Owczarczak-Garstecka explains, "could offer some valuable new insight for the development of bite prevention strategies."
"Prevention messages could emphasize the risk of leaning over a dog and simply advise avoiding contact with a dog when possible or in doubt," she concludes.