Chronic kidney failure, also known as "chronic renal failure," is commonly misunderstood to mean that the kidneys have ceased to function and are therefore unable to excrete urine. Because this isn't true, it's good news. Patients with chronic renal failure (CRF) are defined by their inability to produce urine, not their inability to effectively filter blood. However, despite the fact that most dogs with kidney failure produce a lot of urine, the body's toxic wastes are not effectively eliminated.