Kidney failure in cats can be categorized into acute kidney failure and chronic kidney failure. Acute kidney failure is defined as an abrupt decline in kidney function and chronic kidney failure describes the gradual loss of kidney function. The term “renal: and “kidney” are used interchangeably. Some writers use acute kidney failure (AKF) while others write acute renal failure (ARF).
There is an important and sometimes a difficult differentiation between acute kidney failure and chronic. A new diagnosis can be mistaken for acute kidney failure because it is a new diagnosis when the disease has been present for some time.
Normally functioning kidneys filter excess fluids and wastes from the blood, which are excreted in your cat’s urine. As the kidney disease progresses and reaches an advanced stage, dangerous levels of electrolytes, wastes, and fluids can build up in your cat’s body. Changes that result from kidney failure can affect almost every system. Even with intensive treatment, renal failure in cats can be fatal.
We will address Acute Kidney Failure in cats in this article. For more information about chronic kidney disease, go to Chronic Renal (Kidney) Failure in Cats.
What Causes Acute Kidney Failure in Cats?
There are multiple causes for acute kidney failure. The most common cause is from a urinary obstruction.
- Urinary obstruction – Urinary obstruction is a type of reversible acute kidney failure that is treated by relieving the obstruction. This is one of the most common causes of acute kidney failure in cats. Learn more about Feline Urinary Obstruction.
- Toxic injury to the kidneys – There are several toxins that can damage the kidneys.
- Easter Lily ingestion is an important cause of acute kidney failure in cats. Prevent all access to this dangerous plant.
- A very important toxin that can cause acute kidney failure in cats is ethylene glycol, which is the active ingredient of antifreeze. Antifreeze generally is sweet and tastes good. Very small amounts can be fatal.
- Some antibiotics, such as a class of drugs known as aminoglycosides, can cause damage to the tubules of the kidney. Examples of aminoglycoside antibiotics are Amikacin and Gentamycin.
- Other toxic causes of acute kidney failure in cats include toxicity heavy metals (such as lead or arsenic), contrast dyes used for certain X-ray procedures, and some anesthetics.
- Decreased blood flow and oxygen delivery to the kidneys.
- Low blood flow to the kidneys may occur during anesthesia and surgery, which can damage the kidneys.
- Some drugs such as the non-steroidal anti-inflammatory agents like ibuprofen may also cause ARF by reducing blood flow to certain parts of the kidneys.
- Other causes of reduced blood flow to the kidneys include severe dehydration, shock, poor heart function, heat stroke, and overwhelming infection (sepsis).
- Infections- Acute bacterial infection of the kidneys (called pyelonephritis) can cause acute kidney failure. What Pet Owners Need to Know About a Kidney Infection in Cats.
- Uncommon causes – Uncommon causes of AKF in cats include:
- Glomerulonephritis – acute inflammation of the microscopic filtering devices of the kidney called glomeruli.
- Glomerular amyloidosis – deposition of an insoluble type of protein in the kidney.
- Obstruction by blood clots of the arteries going to the kidneys.
- Hemolytic-uremic syndrome – liver and kidney failure caused by a specific E. coli strain of bacteria.
Signs of Acute Kidney Failure in Cats
Cats are very good at hiding their illness, just by the nature of survival. Sometimes disease can be quite advanced by the time of diagnosis. Signs of acute kidney failure can vary from cat to cat and are often not specific. For example, decreased appetite, vomiting and weight loss are common symptoms associated with many different diseases including kidney failure.
Common signs of acute kidney failure in cats include:
- Decreased appetite or loss of appetite
- Increased or decreased thirst
- Increased or decreased urinations – most often decreased urine production
- Less engaged with family
- Nausea and vomiting
- Sleeping more
- Weight loss
What it Means For Your Cat if They Are Diagnosed With Acute Kidney Failure
If your cat is diagnosed with acute kidney failure, the most important thing to try to understand is why. Causes such as from a urinary obstruction or infection can be successfully treated. Causes such as toxins and blood flow or oxygen delivery abnormalities can be more difficult to treat and may be fatal even with the best care.
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. If your cat is admitted to the veterinary hospital for treatment, they will address the above issues as part of their treatment.
Who’s At Risk for Acute Kidney Failure?
There is no specific breed predilection but older animals are thought to be at greater risk for acute kidney failure. Acute kidney failure in cats is also more common in cats that are outdoor or go outdoors due to their exposure to toxins including antifreeze. There is also an increase incidence of acute kidney failure in the fall and winter due to pet exposure to antifreeze that contains ethylene glycol.
Average Life Expectancy of Cats With Kidney Failure
The life expectancy of a cat with acute kidney failure will vary depending on the cause and response to treatment. For example cats that get acute kidney failure from a urinary obstruction can have a normal life expectancy with proper treatment.