Renal Failure, Acute (Canine)

Acute renal failure (ARF) in dogs is a serious, life-threatening condition characterized by sudden decrease in kidney function occurring over a period of hours to days, leading to abrupt changes in fluid and electrolyte balance.

Common name: Acute kidney failure
Scientific name: Acute renal failure (ARF)

Diagnosis

Signalment
There is no known breed, age or sexual predisposition. Older dogs with preexisting kidney disease may be more susceptible. Free-roaming dogs are more likely to develop ARF from antifreeze (ethylene glycol) ingestion.

Incidence/prevalence
Exact incidence of ARF in dogs is not known. It is less frequent than chronic renal failure (CRF).

Geographic distribution
There is no known geographic distribution of ARF in dogs.

Clinical signs (primary, most to least frequent, scientific term, synonyms)
Lethargy (depression), Anorexia (loss of appetite), Vomiting, Diarrhea, Dehydration, Ataxia (incoordination or drunkenness, such as from antifreeze poisoning), Seizures (convulsions).

Clinical signs (secondary, most to least frequent, scientific term, synonyms)
Polydipsia (drinking more water than normal), Polyuria (urinating more than normal), Urinary incontinence, Foul-smelling breath, Oral ulcers.

Causes (scientific, common term)
Toxic injury, Aminoglycoside antibiotics, Tetracyclines antibiotics, Ethylene glycol (antifreeze), Grapes or raisins, Mycotoxins, Decreased blood flow, Dehydration, Hemorrhage, Congestive heart failure, Septic shock, Heatstroke, Nonsteroidal anti-inflammatory medications, Renal vascular thrombosis (blood clots), Leptospirosis infection, Kidney obstruction.

Organ systems affected (most to least affected)
Kidney, Gastrointestinal, Cardiovascular, Central nervous system, Diagnostic tests, Serum chemistry, Complete blood count, Urinalysis, Ultrasound examination, Radiographic examination, Serology (for infection).

Differential Diagnosis
Chronic renal failure, Addison's disease.

Overview

Acute renal failure (ARF) in dogs is a serious, life-threatening condition characterized by sudden decrease in kidney function occurring over a period of hours to days, leading to abrupt changes in fluid and electrolyte balance. ARF can affect functioning of several organs, since the kidney performs many critical functions in the body.

Kidneys filter blood and remove body waste products, regulate volume and composition of body fluids (electrolytes and minerals), maintain acid base balance and produce some hormones. ARF consists of three phases: induction, maintenance and recovery. The induction phase starts with kidney damage followed by decreased ability of the kidneys to concentrate urine, resulting in increased concentration of waste products in the blood. The maintenance phase may last several days to weeks and is characterized by irreversible kidney damage and decreased urine production.

Animals usually die or are euthanized during this phase unless supported by dialysis. Animals surviving the maintenance phase may enter the recovery phase, which may last for several weeks. Some dogs may suffer permanent damage, and kidneys may never achieve complete functional reserve.

The incidence of ARF in dogs is not known, though it is considered less frequent than chronic renal failure (CRF). Dogs suffering from CRF can convert to ARF. There is no known breed, age or sexual predisposition. Older dogs with preexisting kidney disease may be more prone to developing ARF. Free-roaming dogs are more likely to develop ARF from antifreeze (ethylene glycol) ingestion.

Clinical signs are nonspecific and may include lethargy (depression), vomiting, diarrhea, loss of appetite, dehydration, foul-smelling breath, oral ulceration, urinary incontinence, polyuria (urinating more than normal) and polydipsia (drinking more water than normal). With antifreeze poisoning, dogs may also show incoordination and drunkenness.

Commonly recognized causes of ARF include: toxic injury to the kidneys caused by therapeutic agents (aminoglycoside antibiotics, tetracyclines) and chemicals (antifreeze) or food (grapes or raisins); decreased blood flow to the kidneys resulting from dehydration, excessive bleeding, congestive heart failure, septic shock, heatstroke, administration of nonsteroidal anti-inflammatory drugs and formation of blood clots in the kidney blood vessels (renal vascular thrombosis); infections (leptospirosis); and kidney obstruction (uncommon).

Treatment

Home Care
Subcutaneous fluids (under the skin) can be administered once the patient's condition has been stabilized. The veterinarian may prescribe a diet low in protein and phosphorous.

Professional Care
ARF is a life-threatening condition that requires hospitalization and intensive treatment for several days or weeks. Treatment includes administration of intravenous fluids, correction of acid base balance and electrolyte changes. Immediate treatment may include correction of life-threatening conditions such as hyperkalemia (increased serum potassium) and acidosis. For antifreeze poisoning, treatment with a specific antidote (ethanol or 4-methylpyrazole) may be required. Peritoneal or hemodialysis may be needed in some situations to buy more time for the kidneys to recover or for transplant.

Action
Diagnosis, treatment and a nutritional support plan should be made through your veterinarian.

Outcome
Generally, prognosis from ARF is poor; mortality reaches 60 percent from all cases of ARF. If a pet survives 6 to 8 weeks, then the long-term prognosis improves.

References/Additional Readings

Forrester, SD. Diseases of the Kidney and Ureter. In: Leib, MS, Monroe, WE, ed. Practical Small Animal Internal Medicine. Philadelphia: W. B. Saunders Company, 1997; 299-310.

Kerl, ME. Acute Renal Failure. In: Cote, E. ed. Clinical Veterinary Advisor: Dogs and Cats. St. Louis: Mosby Elsevier, 2007; 32-34.

Author

Safdar Khan, DVM, MS, PhD, DABVT

Editor

Steven Hansen, DVM, MS, MBA, DABVT, DABT

© 2007. The American Society for the Prevention of Cruelty to Animals (ASPCA)