Although both cats and dogs lap fluid using their tongue, felines are far better than canines when drinking. Cats are able to keep things clean when they lap on liquid but dogs smash and spill their way to quench their thirst.
Now, researchers have unveiled why dogs are sloppier drinkers than cats. They also found why larger dogs such as St. Bernards tend to cause more mess than the smaller ones like dachshunds and pugs.
Sunny Jung, from Virginia Tech and colleagues used high-speed cameras and mathematical model to shed light on the fluid dynamics behind how dogs drink.
"When we started this project, we thought that dogs drink similarly to cats," Jung said. "But it turns out that it's different, because dogs smash their tongues on the water surface-they make lots of splashing -- but a cat never does that."
The research team had been conducting studies on how pets drink. Three years ago, they examined how cats drink and found that felines gently place their tongue on the surface of the water before rapidly withdrawing it and pulling up a column of water.
While there are some similarities on how cats and dogs take liquid, the researchers found that there are differences on the way dogs drink water that could be attributed to the mess they create when they drink up.
While the cat's tongue gently touches the surface of the water, the dog's tongue smashes through the liquid which helps explain the amount of splashing they make that do not characterize cats.
"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 researchers reported of their observation. "During this fast retraction fluid sticks to the ventral part of the curled tongue and is drawn into the mouth due to inertia."
The force that cats produce when they pull up their tongue to produce water column is up to double of that of gravity. The force that dogs create, on the other hand, reaches up to eight times more than that of gravity.
Cats also use only the tip of their tongue to touch the water but dogs utilize a large area of their tongue and since the amount of water that their tongue can move increases with body size, bigger dogs cause more water mess compared with smaller dogs.
The study was presented at the American Physical Society's Division of Fluid Dynamics Meeting in San Francisco on Monday, Nov. 24.
