The kidneys have several life-sustaining functions, making them vital to the overall health of the cat. They filter waste products out of the bloodstream and excrete them into the urine. The kidneys also control the cat's electrolyte levels, pH level, and hydration status. In addition, the kidneys produce essential hormones such as erythropoietin, which stimulates the bone marrow to produce new red blood cells.
When the kidneys first begin to fail, the cat's body systems will make adjustments to compensate. For example, the cat may consume more water and urinate frequently in an attempt to "flush out" the waste materials accumulating in the blood stream that should have been eliminated by the kidneys. At some point, however, the amount of dysfunction will overwhelm the cat and the more serious symptoms of chronic kidney failure will result. By the time blood tests show significant changes that alert the veterinarian that renal failure is present, 75 percent of the total kidney mass will have stopped functioning properly.
The most common cause of chronic renal failure is the normal aging process. The disease is progressive and irreversible -- meaning that the cat's prognosis, or prospect of recovering from the illness, is poor. However, treatment can result in short-term improvements of the cat's symptoms and make its life more enjoyable for some time. A cat with chronic kidney failure can live for several weeks to several years with the illness, depending on the severity and advancement of the disease.
