Acute Renal (Kidney) Failure in Dogs
By: Dr. Debra Primovic

Section: Veterinary Care In-depth

Veterinary care should include diagnostic tests of kidney function, including blood tests and urinalysis, and subsequent treatment recommendations.

Diagnosis

Diagnostic tests may be needed to recognize ARF and to exclude other diseases. Tests may include:

A complete medical history and physical examination

A complete blood count (CBC) to evaluate for signs of infection, inflammation, anemia or clotting abnormalities

Blood biochemistry tests to identify the presence of kidney failure. Commonly used tests to identify kidney failure include blood urea nitrogen (BUN), serum creatinine, and serum phosphorus. These test results are abnormally high in patients with kidney failure but these tests alone do not identify whether the kidney failure is acute or chronic. The veterinarian must use other tests and diagnostic reasoning to determine if the kidney failure is acute or chronic.

Urinalysis. Protein, blood or glucose may be observed in the urine of patients with ARF. The presence of microscopic crystals (such as calcium oxalate) can support a diagnosis of ethylene glycol (anti-freeze) poisoning. Microscopic casts of the kidney tubules often are seen with acute injury of the kidney, and white blood cells or casts may be found when kidney infection is present.

Additional diagnostic tests may be recommended for individual pets, including:

Kidney ultrasonography to determine if the kidney failure is acute or chronic and to help identify some specific causes of ARF (e.g. anti-freeze poisoning). Kidneys of patients with ARF typically are normal-sized to large. The presence of small, irregularly-shaped kidneys more often suggests a chronic kidney disease. Dogs that drink anti-freeze often have kidneys that have increased density on ultrasound within a few hours of consuming anti-freeze.

A urine culture to identify urinary tract infection

Blood gas analysis to identify acid-base disturbances

Arterial blood pressure should be monitored because high blood pressure can complicate ARF. Central venous pressure may be monitored with a catheter in the jugular vein, especially if an inadequate volume of urine is produced.

Ethylene glycol testing to diagnose this toxicity; a special test kit is required for this purpose.

Kidney biopsy may be necessary to determine the cause of ARF and to guide treatment and prognosis.