I took Duncan to the vet yesterday because he had been overhydrating and I read that it's important to check for Diabete's if dogs are drinking tons of water. The vet said his heart rate was suspiciously low and thought he might have Addison's disease (Duncan has also had soft stool and on and off vomiting). They took blood, urine, and fecal samples and I'm waiting to hear back. I hope they find out what's going on so we can start treatment. Apparently dogs with Addison's can randomly go into shock and die...scary. The vet thought it could also be diabetes or just a urinary tract infection. The good news is that Duncan was very well behaved at the Vet's because of all the training we've been doing. He sat nicely and didn't bother other dogs and was very nice to the vet and vet tech.