The act of drinking may seem like no big deal for anyone who can fully close his mouth to create suction, as people can. But the various species that cannot do so — and that includes most adult carnivores and our cats and dogs — must resort to some other mechanism, so if you have wondered how our pets drink this is the post for you:
The news is that using high speed cameras, a group of researchers uncovered the mystery of how cats drink. The answer is: very elegantly, and not at all the way you might suppose. Many people think that the raspy hairs on a cat’s tongue, must be involved in this process, instead they're mainly related to the process of grooming. Cats lap water so fast that the human eye cannot follow what is happening, which is why the trick had apparently escaped attention until now. They discovered that cats touch the surface of liquids with their tongues (up to four times per second) before quickly pulling back up, causing a stream of liquid to rise upward. Before gravity pulls the stream back down, the cat closes its mouth around some of it, capturing the liquid. The process is quite different from dogs, which cup the water using their tongues and haul it back into their mouths... probably more efficient but noisier and absolutely less elegant!
Dog owners are familiar with the unseemly lapping noises that ensue when their thirsty pet meets a bowl of water. The dog is thrusting its tongue into the water, forming a crude cup with it and hauling the liquid back into the muzzle. What it's strange in this case is that the "cup" is made twisting the tongue downward and backward towards the lower jaw, in the opposite way you might suppose: