The science behind how dogs drink water actually stumped scientists for a long time. It seems pretty straightforward, right? We can watch them curve their tongues back and splash the water into their mouth almost like a little bowl, but there’s actually a lot more to it than that.
Dogs, like all living things, need water to survive. Now, it’s not like they’re us and can simply grab a glass of tap water whenever they’d like, they have to drink it out of the bowl, and there’s one major biological difference between dogs and humans that allows us to drink water much easier than them. Our cheeks.
Sunghwan “Sunny” Jung, an associate professor at Cornell, studied the ways that cats and dogs drink. He explains, “The problem is, because of their cheeks, they can’t suck in water like humans do…If they tried to suck in water, air would come in from the sides of their mouth. They can’t seal their cheeks to create a sucking motion.”
Prof. Jung found that lots of carnivores, including cats, are lacking in the cheek department. They have what are called “incomplete cheeks.” Jung goes on to say, “Their mouth opening is extended all the way to the side of their cheeks. That large mouth opening lets them open their mouths widely, and helps them kill prey quickly by increasing the biting force.”
This essentially means that a number of carnivores have exchanged the suction power of human cheeks for additional bite strength. You can imagine why this would be the case in the wild and how dogs and other carnivores found this to be more favorable evolutionarily.
So, how do dogs actually drink water? They essentially pool their tongue together, plunge it into the water and bite down on it and swallow it back down their throat. This would be the same motion as if you had a bucket of water in front of you and started plunging your hand up and down through it. This also can explain why sometimes when your dog drinks water, it can get everywhere.
And that’s the science! Your dog is essentially tongue-punching its bowl of water and chomping down on whatever comes back up. This motion is incredibly cool to see in slow motion, so if you’d like to check that out, click here: https://www.youtube.com/watch?v=63Ch2pNkZwU.