Chronic renal failure (CRF) is a progressive disorder most commonly associated with older dogs in which the kidneys slowly lose the ability to concentrate urine and eliminate wastes. The disease is associated with irreversible changes to the kidney structure, such as scarring and loss of nephrons, the functional units of the kidney.
Common names: Kidney failure, Chronic kidney failure.
Scientific names: Chronic renal failure, Chronic renal insufficiency.
Dogs over 7 years of age are more likely to be diagnosed with chronic renal failure. Certain dog breeds (such as the basenji, beagle, Bedlington Terrier, Bernese mountain dog, bull terrier, cairn terrier, Chinese shar-pei, Chow Chow, cocker spaniel, Doberman pinscher, golden retriever, keeshond, Lhasa Apso, Newfoundland, Norwegian elkhound, Pembroke Welsh corgi, Rottweiler, Samoyed, Shih Tzu, soft-coated wheaten terrier and standard poodle) are predisposed to developing renal failure due to inherited or familial disorders. Males and females are equally affected.
Incidence/prevalenceThe overall incidence of chronic renal failure in dogs is approximately 0.6 percent of the population, and the incidence increases with age.
There is no geographic distribution for chronic renal failure.
Clinical signs (primary, most to least frequent, scientific term, synonyms)
Polyuria (increased frequency of urination), Hyposthenuria (dilute urine), Polydipsia (increased frequency of drinking), Anorexia, Vomiting.
Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Weight loss, Dehydration, seen because the kidneys lose the ability to reabsorb water, Blindness due to hypertension or high blood pressure, Oral or stomach ulcers, Exercise intolerance due to anemia (low red blood cell count), In young animals, softening of the jaw or bones of the skull, due to redistribution of calcium and phosphorus within the body (also known as renal osteodystrophy), Muscle weakness, Seizures (rare).
Causes (scientific, common term)
Idiopathic (where the cause is unknown), Pyelonephritis (kidney infection), Neoplasia (cancer) such as renal carcinoma or metastatic cancer with the original tumor in another part of the body, Amyloidosis, a condition where a type of protein called amyloid is permanently deposited in the kidneys, Nephrolith (kidney stone), Glomerulonephritis, an immune disorder that causes inflammation of a certain part of the kidney called the glomerulus, Systemic lupus erythematosus (lupus), Congenital disorders, such as polycystic kidneys, renal dysplasia or hypoplasia, where the kidneys fail to develop properly as an embryo or fetus, Any cause of acute renal failure if not fully treated can progress to chronic renal failure if the animal survives for a long enough time.
Organ systems affected (most to least affected)
Kidney, Cardiovascular System , Digestive tract, Eyes, Bone marrow, Parathyroid glands, Nervous system.
Complete blood count, Blood chemistry analysis, Electrolytes, Urinalysis, Urine protein/creatinine ratio, Urine culture and sensitivity, Blood pressure, Ultrasound examination, Radiographs (X-rays), Renal biopsy (potential), Urine microalbumin (potential), Glomerular filtration rate (potential).
Acute renal failure, Cushing's disease (hyperadrenocorticism), Diabetes.
Chronic renal failure (CRF) is a progressive disorder in which the kidneys slowly lose the ability to concentrate urine and eliminate wastes. The disease is characterized by irreversible changes to the kidney structure, such as scarring and loss of nephrons, the functional units of the kidney.
The kidney's role in filtering wastes, maintaining electrolyte balance and endocrine function affects a number of other organ systems as well. Water loss through the kidneys results in increased urination (polyuria), dilute urine (hyposthenuria) and increased water drinking (polydipsia). The buildup of nitrogen wastes in the blood due to decreased filtration may cause anorexia and vomiting.
CRF can also lead to high blood pressure (hypertension) resulting in blindness, digestive tract ulcers, anemia, electrolyte imbalances (especially potassium, phosphorus and calcium), increased parathyroid gland activity, muscle weakness and possibly seizures.
The changes and loss of function occur over several months, making it difficult to determine the exact cause of CRF in most cases. Disorders that may lead to CRF include acquired conditions (such as kidney infections and kidney stones), congenital disorders in which the kidneys fail to develop properly, disorders caused by the immune system (such as lupus and amyloidosis) and cancer. Any case of acute renal failure can also develop into CRF if not fully treated.
CRF can occur in any age male or female dog. However, it is more common in dogs over 7 years. Certain breeds have inherited or familial disorders that can predispose them to developing CRF, such as the basenji, beagle, Bedlington terrier, Bernese mountain dog, bull terrier, cairn terrier, Chinese shar-pei, Chow Chow, cocker spaniel, Doberman pinscher, golden retriever, keeshond, Lhasa Apso, Newfoundland, Norwegian elkhound, Pembroke Welsh corgi, Rottweiler, Samoyed, Shih Tzu, soft-coated wheaten terrier and standard poodle.
After determining the severity of CRF, home treatment often involves administering subcutaneous fluids (fluids under the skin), dietary changes and medication to alleviate symptoms.
When CRF is suspected, the dog should undergo a complete physical examination with blood and urinalysis. Other diseases must be ruled out, including diabetes and Cushing's disease, and an appropriate treatment plan implemented. This involves blood work, such as a complete blood count and chemistry analysis, urinalysis, urine culture, urine protein/creatinine ratio and blood pressure measurement. Other additional tests may include an ultrasound examination, X-rays (radiographs), kidney biopsy, urine microalbumin and measurement of the glomerular filtration rate.
Treatment is designed to alleviate symptoms that decrease quality of life and to slow the progression of the disease. Treatment may involve intravenous (IV) fluids, blood pressure medication, antibiotics for kidney infections, stomach acid reducers, medication to modify electrolytes (especially potassium, phosphorus and calcium), erythropoietin or blood transfusions to address anemia, and dietary changes such as supplementing the diet with omega-3 polyunsaturated fatty acids or feeding of a diet low in protein and phosphorus.
Diagnosis and management of chronic renal failure will be determined by your veterinarian.
CRF is an irreversible condition. When detected early, treatment can slow its progression. Late-stage CRF has a poor prognosis.
Polzin, DJ, Osborne, CA, Ross, S. Chronic Kidney Disease. In: Ettinger, SJ, Feldman, EC, ed. Textbook of Veterinary Internal Medicine, 6th Ed. St. Louis: Elsevier Saunders, 2005; 1756 - 1785.
Grauer, GF. Renal Failure. In: Nelson, RW, Couto, CG, ed. Small Animal Internal Medicine, 3rd Ed. St. Louis: Mosby, 2003; 608 - 623.
Adams, LG. Renal Failure, Chronic. In Tilley, LP, Smith, FWK, ed. The 5-Minute Veterinary Consult Canine and Feline, 3rd Ed. Baltimore: Lippincott Williams & Wilkins, 2004; 1124 - 1125.
Cristine Hayes, DVM
Steven Hansen, DVM, MS, MBA, DABVT, DABT
© 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)