The Messy Physics of Canine Slurping

How dogs overcome the disability of having a big floppy face.

by Michael Byrne
Nov 30 2014, 1:00pm

​Image: davebloggs007/​Flickr

​Dogs must think that we're fully idiots. It's enough that humans have to wear pants and shoes and cut our food into pieces, we can't even drink water, that most basic necessity, without help from a tool. Never shall we know the convenience of just sticking our snouts into whatever disgusting water supply happens to be around.

Well, at least we can drink without making a holy mess of everything. That's the dog downside—those big toothy, floppy faces can't generate suction. Instead, they have giant weird tongues, the fluid dynamics of which have only recently been described. Actually,​ it was only last week, at the American Physical Society's Division of Fluid Dynamics' annual meeting in San Francisco, where a team of Virginia Tech researchers laid out their latest study of canine physics.

"When a dog drinks, it curls its tongue posteriorly while plunging it into the fluid and then quickly withdraws its tongue back into the mouth," the ​presentation's abstract explains. "During this fast retraction fluid sticks to the ventral part of the curled tongue and is drawn into the mouth due to inertia."

They kind of just grab a drink and whip it back toward their mouths (at five times the speed of gravity). They then snatch the blob of liquid out of the air before it falls back down. That's the plan anyway. It doesn't always work, which would explain well enough the small flood continually collecting by the food bowls. Way to go, dogs.