Never wondered about that until now that you have brought it up @Hal Pollner. But I'll be sure to watch as our "adopted" and part time dog laps up the water from our bird bath on an almost daily basis and I'm sure I will find out the answer to that.
Ive never really watched Pickles that closely when he's drinking but I sure can hear him even a few rooms away. He probably won't drink while I'm watching anyway, he has a weird habit of waiting to drink until Ive left the room after filling his water bowl. I see him standing in front of it with his head turned towards me and watching....he's a character!!
Probably the best way to settle the question is to take high speed videos and play them back in slo-mo. Our dogs dart their tongues in and out of their water bowls too quick for me to get a visual image. Hal (Here's Barbie, who "sings" when I play the harmonica! )
This OP brings up another of my long-term imponderables, most of which are evidently trash-can worthy. Here it is anyway: I have observed many animals' way of getting water. Dogs, cats, many others lap it up a tiny bit at a time, using their tongues; they seem to be unable to "slurp" it in using suction. Goats slurp it in readily and easily, in quantity, and quickly. Horses, I think too, but not certain. Anybody know if there is some relation between "lappers" and "slurpers"? At risk of being seriously intervened with here, I'll throw this out: mammals I know to slurp water, eat no meat! Frank
@Von Jones Nice! Just like an upside-down trough. When you think about it, it makes sense as the tongue flings the water back straight to the throat area, whereas over it's top it would have to travel farther. Frank