Acute Renal (Kidney) Failure

Posted on June 12, 2015

Acute Renal (Kidney) Failure

The kidneys remove toxins and waste from cell function in the body.  Failure to remove the toxins is renal failure, and acute means it develops over a couple days.   Despite advances, it is a serious disease that 60% of cats and dogs die from or are put to sleep.

Causes of acute renal kidney failure

A.      Poisons can cause kidney damage.

1.       Antifreeze or ethylene glycol is

2.       Raisins

3.       Pain pills, aspirin, Advil (and generics)

4.       Lily plants are poisonous to cats.

B.      Severe infections resulting from bacteria can quickly cause kidney failure, resulting spontaneously or from reasons such as kidney stones or partial urine blockage.  Leptospirosis is a bacterium that can cause kidney failure, spread by contaminated urine or water from other animals.

C.      Other causes of kidney failure;

1. Decreased blood flow through the kidneys

2. Dehydration from severe vomiting and diarrhea

3. Massive blood vessel damage from heatstroke

4. Massive damage to blood vessels by bee stings, snake bites

What are the early symptoms?

1.       Excessive thirst

2.       Excessive volume of urine


What are the later stage symptoms?

1. Lethargy

2. Poor appetite

3. Vomiting

Severe kidney failure

4. Urine may decrease or stop all together

5. Digested blood in the stool may indicate worsening kidney failure

6. Vomiting digested blood appearing like coffee grounds

Tests to determine kidney failure the presence and the severity

1. Blood test

2. Urine test


Tests to determine the cause of kidney failure (The cause of kidney failure is not always determined. A kidney biopsy may be recommended.)

1. X-rays

2. Sonogram (ultrasound)

3. Special blood tests


A.      Intravenous fluids (IV) are usually the initial treatment, as it helps restore hydration and flush substances from the blood stream.  Urine production is monitored during therapy, as decreased amounts require other therapies such as diuretics (water pills) to increase urine output.

B.      Other medications are common

1. Antacids are given, as kidney failure can result in stomach ulcers.  Bleeding ulcers require medications to coat the ulcer.

2. Antibiotics are given for kidney failure suspected is from infection.

C.  A temporary tube may be recommended for pets refusing to eat.

An acute kidney failure condition can change rapidly, therefore requiring continuous monitoring of blood pressure, weight, electrocardiogram and blood tests.  A urinary catheter may be placed to measure urine volume. In acute kidney failure, potassium levels (an electrolyte) can increase to dangerous levels that slow the heartbeat or even stop it.  In chronic kidney failure, potassium levels tend to decrease.  Very high blood pressure can develop with kidney failure requiring medications. The pressure can cause the blood vessels in the eye and brain to burst.  If fluid builds up in the lungs, belly bloating, swollen legs and shortness of breath may manifest.

Animals with acute renal failure that do not respond to IV fluids may require advanced treatment due the following.

1.       Dangerously high potassium levels detected

2.       Fluid in the lungs

3.       Lack of improvement in laboratory results


Two therapies considered are peritoneal dialysis and hemodialysis, both costly.  The therapies allow up to 50% of animals to recover depending on the underlying cause.  Some may recover completely while others will have long-lasting kidney damage treatable at home.

Peritoneal dialysis requires 24 hour care requiring tube to be placed into the belly to put fluids in and drain out after a couple hours.  The procedure flushes toxins that kidneys are not removing.  The fluids are flushed in and out.  Infection around the tube and clogging of the tube are both a frequent complications.

Hemodialysis requires putting a large IV catheter in a vein to remove portions of blood at a time.  It is then cleaned by a machine.  It is effective, but done in only a few veterinary hospitals.  Dialysis is reserved for pets that treatments have failed and death will occur.  Only half of pets recover, some completely and other with lasting damage that can be controlled at home.