Hi. I'm Dr. Gotthelf. I have been a vet for 35 years and I would like to use my experience to help you with your pet's medical problem.
With a BUN of 88 and a creatinine of 2.5, I would suspect that she may be in chronic renal failure. YOUr vet needs to run a serum phosphorus and a urine specific gravity to determine if the kidney is able to concentrate urine.
The treatment for your dog should include intravenous fluid therapy to dilute and to helps the kidneys excrete toxins that have built up. Just giving water by mouth will not do it. There are other things, like a special low protein diet and phosphate binders that may be necessary. You will need to discuss all of this with your vet.
Thank you very much but am just curious if it is strange for a dog to stop eating and drinking all of a sudden and what we need to do to get her to eat and drink? Do you typically see a change in their eating and drinking habits after fluid therapy?
When dogs have kidney problems, the toxins cause decreased appetite. Many dogs with kidney problems develop ulcers in their stomach from excessive secretion of acid. That causes pain and distress. Often antacids and drugs like Tagamet or Zantac are used to decrease stomach acid production. Fluid therapy helps to dilute the toxins and it also helps the kidney push toxins through. We do something called intense diuresis for these dogs by using concentrated glucose solutions or mannitol in the IV bag to make the kidneys allow more fluid to go through them.