Do dogs get enough to drink?

Always when I hear a dog barking -- howling, really -- in the distance, I feel sorry for it. (Yes, and if it goes on and on, I also feel annoyed.) Apart from the obvious thought that the dog has been left out on its own and is lonely, I sometimes wonder whether anyone has provided it with enough fresh water to drink. I mean, how could they? It's a hot summer's day and the dog is left in a backyard or free to roam the countryside where it lives. Unless someone is willing to put out ten (at least) large bowls of ice water, the last of which will still be fresh and cool when the first is dried up and the second-to-last is mainly slobber, how are such dogs getting enough water?

Humans get dehydrated and often seem barely to notice it. But the dehydration of dogs, with their panting tongues, can't be ignored. And dogs need drinking water in a way that we don't, since we can perspire to cool ourselves but dogs rely on that wet panting mouth. 

We are big drinkers in my family, and I don't just mean of the alcohol variety. Our attitude to water is 'don't leave home without it'. This is partly because we live and vacation in warm climates. But it's also because we have a very heat-sensitive dog -- a Boxer, the star of How To Train Your Human -- who needs a drink at the immediate end of every outing or walk. As soon as she's back in the car, I whip out the dog-drink dispenser with fridge-chilled water and she happily slurps away (she loves the car as if it were a chariot of heaven, so she's often out with us in it). On long trips, we bring two of these bottles, and use them, too. When she steps forward on the console to ride between us, and gives me that "significant look", I know that she wants water and I give her some. We humans also have a bottle of water or thermos of tea in for us: there's nothing worse than being stuck in a traffic jam or unable to stop when your brain feels like it's drying up for lack of moisture!

One thing I've noticed with Chummy is that, just like a human, she may not always realize that she's thirsty. She may get up on the bed on a warm night, and we've settled in and it seems that the time for being at her water bowl has passed. Sometimes I check her bowl and see that -- oops, it's dry or nearly dry or got bits floating in it. I am constantly refilling that bowl, but sometimes I get distracted and forget to check. If I think that my dog may not have had all the water she wants, I'll bring the refreshed water bowl to the bedroom and offer it to her. When she's sleepy, it takes her a few moments to decide whether she wants it or not. I don't pull it away too quickly: she doesn't decide instantly as a human might. Sometimes she shows no interest, but other times -- after a little suspense for me -- she dips her head down, and I feel so glad that I thought to give her that last comfort before sleep.