Welcome to Just Answer! I would like to help you and your dog with this question, but need a bit more information in order to better assist you.
If diabetes is uncontrolled for an extended period of time, without enough insulin to push the glucose into the cells, the body starts to burn fat to try to provide calories. This is because the cells are STARVING even though the animal is eating. There is just no way to deliver the glucose to the cells without adequate insulin.
So, once fat burning reaches a critical point, the body produces ketone bodies as a by-product of the fat burning. Ketones are dangerous. They drop the pH of the blood and this quickly causes serious problems. In some dogs, they will go into shock within days of developing ketones, in some dogs it might take a week or two.
So, if you have a diabetic patient with ketones in urine, then he has diabetic ketoacidosis (DKA).
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The above is given for information only. Although I am a licensed veterinarian, I cannot legally prescribe medicines or diagnose your pet's condition without performing a physical exam. If you have concerns about your pet I would strongly advise contacting your regular veterinarian.
Best wishes, Fiona