Until we found out about a study by Sunghwan Jung of the Department of Biological and Environmental Engineering at Cornell University and a team of scientists on how exactly dogs drink water, we assumed that they were simply scooping up water and swallowing. We were completely wrong.
In short, dogs drink the water that splashes on the front of their tongue as they lap from a bowl rather than the water they scoop up, but there’s more to it than that. In this post, we’ll share what Professor Jung and his team discovered about how dogs actually drink. Stay tuned for some fascinating facts.
How Do Dogs Drink Water?
When humans drink, we suck in water with the help of our cheek muscles. Dogs, on the other hand, can’t suck in water as humans do due to having incomplete cheeks. Dogs are built this way to make it easier for them to catch and kill prey in the wild. So, instead of sucking, they curl their tongues backward into a ladle-like shape and lap at the water, in and out.
This in-and-out motion is what causes water to splash out onto the floor, and has gained dogs a reputation for being “messy” drinkers. That said, this is just how dogs are supposed to drink! They curl their tongues because it helps them to pick up more water than a straight tongue would.
The researchers led by Sunghwan Jung recorded 19 dogs drinking and found that most of the water that dogs scoop up—or ladle up— with their tongues does not get swallowed. What actually happens is that the lapping motion creates a water column that sticks to the dorsal (front) side of the tongue when the tongue goes back into the dog’s mouth. They close their jaw on this water column at just the right time, and this is the water that gets swallowed.
The speed with which dogs perform this feat is equally impressive. Though the results showed that dogs put their tongues into the water at a “relatively low speed”, when the dogs’ tongues retracted into their mouths, researchers recorded speeds of 0.7–1.8 m/s.
Do Cats Drink Water in the Same Way?
No. Cats also have incomplete cheeks and so lap at their water, too, but the way they do this is different from dogs. Researchers found that cats move the tip of their tongues in a manner that causes the water to move upwards. This is in contrast to dogs, who bend their tongues backward to drink.
They then bite down on the water at the right time, just like dogs do. Cats are also tidier when they drink, gently lapping at the water rather than splashing/hitting it with their tongues.
The science behind how dogs drink is pretty intriguing. With the lack of complete cheeks and the ability to perform sucking motions as humans do, a dog’s drinking ability is a real biological and physical feat—one that had remained something of a mystery until Sunghwan Jung and his team’s study, which was conducted in 2015.
If learning about this study has aroused your curiosity, we won’t be surprised if you find yourself kneeling down and having a good look next time your dog is drinking. If someone comes in, just tell them you’re witnessing science in action!
Featured Image Credit: Pixabay