One of my dogs, King doesn't seem to ever drink much, but pees a tremendous amount, it's very potent smelling and very yellow too. Between that and his sleeping more than any previous dog I ever had, I was worried and had a bunch of blood work, and urine analyzed. Total waste of money, except for my peace of mind, as he came back perfect in every catagory. That was 6 years ago. He still sleeps about 20 hours a day and pees a tremendous amount.
He's the healthiest dog I have ever had, by far.
His sister, Molly has major allergies, and bad hips, drinks a LOT of water, and pees very little, and it's not bad smelling (for pee) at all. I don't really understand it, but her blood and urine tests all came back fine too. She sleeps less than half as much as King does.
It's amazing to me how they could be from the same litter, and have the same parents and be so different in so many ways.