A visit to our kitchen requires carefully watching one’s step, particularly in bare or stocking feet. There is inevitably a large splash zone on the floor around the dog bowl, as well as trails of water leading away from the site. That’s because Katie, our 9-year-old mutt is the messiest drinker of any dog I’ve encountered. However, she is not unusual. Studies show that all dogs – not just mine – are sloppier drinkers than cats and other animals,
Dogs and cats do not employ suction when they drink like humans. They cannot close their lips fully to create the suction. As a result, canines and felines lap up liquids using their tongues, but the results are very different. Dogs splash a lot, but a cat never does,” according to Sunny Jung, a Virginia Tech biomechanical engineer, who is one of the study’s authors. Additionally, the bigger the dog the bigger the puddle is generally. The study on “How dogs drink water” was presented today in San Francisco at the American Physical Society’s Division of Fluid Dynamics Meeting.
In their research, the scientists used video cameras to study how dogs and cats differ in drinking styles and strategies. The research showed that different animals use distinctly different strategies to imbibe water. Cats tend to flick the water, whereas dogs then to plunge their tongue into it.
It turns out that dogs do not use their tongues as ladles to scoop up water as previously believed. The videos showed that dogs tend to lap up the water by whacking it from above and pulling the water upward as fast as they can. It is almost like they are plunging a solid tongue into the water and rapidly accelerating it up to lift some liquid up to swallow. The larger the canine, the wider the tongue surface area whacking at the water and the larger the splash zone. The videos shows that dogs accelerate the upward thrust to approximately five to eight times faster pulling upward on their tongues than pushing downward. Dogs close their mouths just before the water falls back to the bowl (ours sometimes forgets this step).
The same research team studied the drinking habits of cats three years ago. That research should that cats tend to tend in an elegant two-step process. They gently put their tongues on the surface of water; they then rapidly retract it pulling a column of water up underneath the tongue.
Jung admits that when the team started the project, they thought that dogs used a similar drinking process as cats. However, “It turns out that it’s different.” Jung noted, “Dogs smash their tongues on the water surface…but a cat never does.”
Jung and the research team tried to determine the fundamental physiology involved and how it impacted the ability to drink. They reviewed models of the dog’s tongue and mouth. For their model, using glass tubes, they simulated a dog’s tongue and mimicked the tongue’s acceleration during the exit process. They measured how much water is withdrawn (and how much falls off around the bowl). So, this process does not just seem inefficient process; it ensures that all dogs, as a rule, are sloppier drinkers than cats. But Katie, we love you anyway.
By Dyanne Weiss