Dr. Lee, thank you for this information. This is a subject I've been dealing with for several years. When we adopted a 4-year-old Scottie, she would inhale her water bowl. She also had many accidents, producing clear, water-like urine. We thought that she was just getting adjusted to her new home and actually worried that our male Scot was not drinking enough. When we mentioned this to our vet, he was very concerned. It ended up that our little girl was drinking 12-15 cups of water per day (at 30 lb body weight.) We ran so many tests to come to the diagnosis of #20 on your list. She would get stressed and then drink. The more she drank the more she flushed the salts from her body, making her drink more (and need to urinate more). This was a serious condition and it took several months of medically supervised care to get her water levels decreased to normal. But it took tests for Cushing's, both diabetes and blood and urine checks to get our diagnosis--and it took time to get our diagnosis. The vet needed to rule out all the medical issues to come to the behavioral diagnosis.
I still monitor how much she drinks. She has multiple health issues now, and if she gets stressed, she drinks more. It is a sign to me that she is not feeling well.