Your Dog’s Frenzied Slurping Is In Fact A Finely-Tuned Water-Transport Machine

Nothing better illustrates a dog’s dull-witted enthusiasm than its chaotic slurping from a water bowl. Like a non-swimmer trying to stay afloat, the doggy scrabbles and laps, desperate to get a drop to drink. It’s the very essence of inefficiency. Or is it? New research finds that your doggy’s lolloping licks may in fact be a finely-tuned suction machine.

Unlike humans, dogs don’t have cheeks, which means they can’t create any suction in their mouths (remember this the next time you see a cute photo of a dog drinking a cocktail through a straw). Instead, they have to pump the water into their mouths. Their seemingly haywire lapping raises a column of water from the surface, and then the dog bites down on this column with precision timing. The messy appearance (and sound) of the whole process is down to the fact that the dog curls its tongue backwards, enabling it to “drink more per lap than with a straight tongue,” says the report^[1].

So the dog isn’t actually scooping water into its mouth–it’s whipping it into an unstable column and then taking a bite. This explains the flurry of energy when a dog drinks, compared to a cat, which drinks more like you imagine it does, by dipping just the tip of the tongue into the water and gently scooping up the liquid, which sticks to the top of the tongue.

To explore the mechanisms of dog drinking, researchers at Virginia Tech’s Bio-Inspired Fluid Lab used a high-speed camera to film 19 dogs as they drank. The results helped build a laboratory model of a drinking dog and study how their tongue controls fluids.

“Cats tend be viewed as neater, dogs are messier,” graduate student Sean Gart said in a press release^[2], “but dogs really have to accelerate their tongues to exploit the fluid dynamics of the water column.”

These findings will not only help you to marvel at the elegance of your dog’s otherwise moronic behavior, but it will also form part of the Bio-Inspired Fluid Lab’s body of research, which applies natural principles to practical problems.