That’s a difficult question to answer and the answer is unpleasant. Most pets are diagnosed with kidney problems at a very late stage. Some of them have over 60-70 % of their kidney tissues damaged by the time there is any noticeable health issues. After that stage , there is a rapid loss of tissues, increase in toxins in the blood. An onset of other conditions quickly arrive. Chances are the dog will last less than a week to a month.
But with treatment, chances are that your dog will live up to 4 years, comfortably. The right medication and treatment along with love and care should go a long way for your dog when its suffering from kidney problems at an elderly age