Overview of Canine Acute Renal Failure (ARF)
Acute kidney failure (also known as acute renal failure or ARF) is characterized by an abrupt decline in kidney function that leads to changes in the chemistry of the body including alterations in fluid and mineral balance. The changes that arise as a result of ARF affect almost every body system.
The kidneys filter blood, remove the waste products of metabolism, and eliminate them in the urine. The kidneys also regulate the volume and composition of body fluids (including mineral concentrations and acid base balance), and produce hormones that stimulate the production of red blood cells (erythropoietin) and regulate calcium balance (calcitriol).
Acute kidney failure can be caused by toxic injury to the kidneys, decreased blood flow and oxygen delivery to the kidneys, infections, obstruction of the kidneys and prevention of urine elimination caused by a ruptured bladder.
The recent recognition of kidney failure is not necessarily the same as acute renal failure, since some animals with chronic kidney failure tolerate it for some time before symptoms are apparent.
There is no specific breed predilection but older animals are thought to be at greater risk for acute kidney failure. Acute kidney failure is more common in the fall and winter due to pet exposure to anti-freeze which contains ethylene glycol. Dogs that are allowed to roam outside without supervision and working dogs potentially have increased exposure to ethylene glycol.
The symptoms of ARF, although often severe, are not specific. Even with intensive management, ARF is a very serious disorder and often is fatal.
What to Watch For
Signs of acute renal failure in dogs include:
Diagnosis of Acute Renal Failure in Dogs
Your veterinarian will take a complete medical history specifically questioning exposure to ethylene glycol (anti-freeze), recent surgery or anesthesia (possibly causing decreased blood flow to the kidneys), exposure to drugs toxic to the kidneys (aminoglycoside group of antibiotics and non-steroidal anti-inflammatory drugs) and previous illnesses. The following diagnostic tests may also be necessary to recognize acute kidney failure and exclude other diseases. Tests may include:
Treatment of Acute Renal Failure in Dogs
ARF is a life-threatening serious condition that requires hospitalization and intensive treatment. Treatment consists of identification and correction of life-threatening problems while searching for the underlying cause of ARF. Treatment for ARF may include one or more of the following:
Acute renal failure is a life-threatening condition and there is no effective home treatment. If you suspect your pet has this condition, or if you even suspect your pet may have consumed even a small amount of anti-freeze, you should call your veterinarian immediately. Your veterinarian may instruct you to induce vomiting before bringing your pet to the hospital.
Administer any medications prescribed by your veterinarian. Follow-up examinations and laboratory tests are important to assess your pet's response to treatment. Allow free access to fresh clean water.
Avoid exposure to ethylene glycol (anti-freeze), and avoid exposure to drugs known to be toxic to the kidney (e.g. aminoglycoside antibiotics and non-steroidal anti-inflammatory drugs). Don't allow dogs to roam outside unattended.
Vaccinate your dog for leptospirosis as recommended by your veterinarian. This vaccine usually is included in routine vaccination protocols.
In-depth Information on Acute Renal Failure in Dogs
Acute renal failure (ARF) is a life-threatening disorder that can affect dogs of any age.
Acute renal failure may be caused by decreased blood flow to the kidneys (called ischemia) or exposure to certain drugs or chemicals that are toxic to the kidneys.
The most common causes of death during treatment of ARF are high blood potassium concentration, acid-base disturbances, very high concentrations of waste products in the blood that do not improve with fluid therapy and excessive administration of fluids with fluid accumulation in the lungs.
Animals unable to produce urine despite medical treatment have little chance for survival without peritoneal dialysis (infusion and removal of fluid into the abdominal cavity to remove waste products from the body). Hemodialysis can be performed in animals but is only available at selected referral hospitals and is very costly.
The prognosis for recovery of kidney function in ARF depends on the severity of the kidney damage, the underlying cause of ARF and supportive treatment.
Other medical problems can lead to symptoms similar to those encountered in ARF. A thorough medical evaluation is needed to diagnose ARF including laboratory testing and diagnostic imaging (X-rays or ultrasound). Warning signs that owners may see in pets with ARF include complete loss of appetite, marked lethargy, and vomiting. Unfortunately, these symptoms are very non-specific and may be caused by many other disease conditions. If is important to consult your veterinarian promptly.
Veterinary care should include diagnostic tests of kidney function, including blood tests and urinalysis, and subsequent treatment recommendations.
In-depth Information on Diagnosis
Diagnostic tests may be needed to recognize ARF and to exclude other diseases. Tests in dogs may include:
Additional diagnostic tests may be recommended for individual pets, including:
In-depth Information on Therapy
Treatments for ARF in dogs may include one or more of the following:
Close patient monitoring is vital. Monitoring may include serial body weight (to facilitate proper fluid therapy), measurement of urine output (often with a urinary catheter), packed cell volume (an indication of the percentage of the blood that consists of red blood cells), and total plasma proteins to monitor fluid volume. Serial determination of serum biochemistry tests is necessary to determine if the animal is responding to treatment.
Treatment for ARF may require several days or as long as two to three weeks depending on the underlying cause of ARF and the response of the individual animal to treatment. This prolonged hospitalization can be frustrating for all concerned, because it frequently is impossible to predict the outcome. If conservative medical treatment fails, peritoneal dialysis (or in exceptional circumstances hemodialysis) may be a treatment possibility. Referral to a specialist or 24-hour critical care facility is required for dialysis treatment.
Euthanasia must be considered for pets that do not respond to treatment.
Follow-up Care for Dogs with Acute Renal Failure in Dogs
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical. Administer prescribed medications as directed by your veterinarian and be certain to contact your veterinarian if you are experiencing problems treating your dog. Specific instructions for home therapy vary on an individual dog basis.