@Duke:
Good advice, but as you know, "You can lead a horse to water, but you can't make 'em drink." LOL - How do you make them drink? The water bowl is full.
If Duke likes veggies, boil some potatoes, cabbage, or whatever you have. Let the water cool then see if the dog will drink it. Mine LOVE it!
If you have a bit of chicken or a beef bone, make some homemade broth and see if Duke will drink it.
Or you could add a few drops of canned chicken or beef broth to water. Not too much though as it is usually too salty.
Sometimes you will get better results if you use a different container than the regular water bowl for this. If the dog thinks it is "forbidden" they seem more interested.