I'm not sure what this has to do with the question raised, but the first Doberman that I owned--I was 15--was a German-bred dog. He had numerous champions and international champions in a 4-generation pedigree. He had never been trained, but he was never off guard. He would do without water before he would put his head down into a bucket or other container that he could not see over the top of while he was drinking. How he liked to drink was this way: I would turn on the faucet and he would lap from the stream of water as it fell from the faucet--always alert and watching his surroundings. Subsequent Dobes that I owned, after a few generations of pet/show breeding, were not even in the same class with this dog.
My point is that dogs can, and do, learn to drink from a falling stream of water.
And dogs can die from heat and dehydration in the field.
Tracker, my AKC Lab, sure does like to find a pond or creek when we are out roaming around. But then, so does Stretch, a dog that I believe to be a Pit/Italian Grayhound cross. (When my niece found her as a tiny, nearly frozen-to-death pup in a parking lot, she didn't have a pedigree with her.) Interestingly, Tracker and Stretch both go through identical antics when they find a pool of water: they have a way of dipping their heads under the surface.