The kidneys are responsible for filtering and cleansing the blood of waste products and conserving water and returning it into the circulatory system. Chronic renal failure occurs when the kidneys gradually lose their ability to perform these functions. Older dogs and cats are most frequently afflicted with chronic renal failure, which may also be called chronic kidney failure.
After an animal has lost a significant portion of its kidney function, it will often drink and urinate more than normal, become lethargic, stop eating, vomit, and lose weight. A veterinarian will use blood work and a urinalysis to determine if an animal's kidneys are functioning properly. Other tests may be necessary to uncover an underlying cause for an animal's poor kidney function, but in many cases, the reason is never clear.
Treatment for chronic renal failure includes fluid therapy, special diets that ease the work of the kidneys, and on an as needed basis, medications to treat high blood pressure, excessive gastric acid secretion, anemia, and abnormal levels of potassium and phosphorous in the body. Animals may be hospitalized until their conditions are stable and then sent home for their owners to administer maintenance treatments, which may include fluids injected under the skin on a regular basis. Kidney transplants are available for eligible cats. Chronic renal failure does become worse with time but the speed with which an animal's condition will deteriorate is extremely variable. Some animals will live well for many months or even years with little treatment, while others may not survive their initial hospital stay. Euthanasia is frequently necessary once a pet's condition has declined to an unacceptable level.
Written by: Jennifer Coates, DVM
Last reviewed: October 2, 2008