To be honest, if the pup has untreated diabetes insipidus, I don't see how it can last that long untreated. I agree, restricting fluids isn't good, what I meant be reasonable amount is not to let her drink nonstop and become water intoxicated. Regardless, this pup needs some electrolytes or it's in trouble. Hopefully, its something else, I just cant think of anything other than diabetes mellitus that would make it so thirsty. A uti shouldn't do that. Could it be obsessive/compulsive?

Pearl, I just read the article you posted, very informative. We see it in the hospital with people, but we catch it and treat it so quickly on our postop patients, I really don't get to see the full effect. I have never seen congenital in people, it probably exists, but is rare. It looks like it might be more prevalent in dogs., according to that article. Well, I hope it isn't that, cause it looks like a lifelong battle if it is. Good luck, Lisa. Get a really good vet specialist if DI is the diagnosis.

here's another one i found: http://www.petdiabetes.org/diabetes_insipidus.htm