Feline Renal Failure ~ Pawprints and Purrs, Inc.

Pawprints and Purrs, Inc.
Cat Health Care
Information by Condition or Disease

A Non-Profit 501(c)(3) Organization
All donations are tax deductible
Copyright © 1997 - 2010

Any health care links located here are NOT to replace a veterinarian visit; please take your cat to a vet immediately at any sign of odd behavior or any symptoms of illness or injury. Call your vet and describe your cat's symptoms with any of your concerns about the cat's well-being. Your veterinarian may discover changes in your cat's health that you have overlooked. It is always better to err on the side of caution.

Feline Renal Failure

A cat's urinary system consists of the two kidneys and bladder, the ureters (small tubes) that connect them, and the urethra which urine is emptied from the bladder. There are two serious conditions that commonly affect the urinary system of cats. In a case of renal failure, the two kidneys - despite the in-built spare working capacity that they have - are so affected by disease that they cannot carry out their normal functions, while feline lower urinary tract disease (known as FLUTD) involves a cat's bladder and urethra.

The two kidneys have several vital functions, including removal of the waste products of protein processing from the body, and a role in maintaining the body's water levels and of the chemical substances dissolved in that water.

The filter-like working parts of a kidney are called nephrons, each of which consists of a blood filter attached to a complex piece of pipework called a tubule.

Both kidneys contain hundreds of thousands of nephrons. When a significant number of them become damaged or are destroyed by disease, such that the remaining nephrons cannot cope, the cat will suffer from renal failure.

Common Symptoms

Even though the disease that incites chronic renal failure may have been present for many years, symptoms often seem to appear suddenly. The reason for this is that a cat can survive without showing any symptoms of kidney problems even when the whole of one kidney and one-third of the other have been put out of action. In chronic renal failure, the damage to the kidneys is usually irreversible and progressive.

The symptoms may include the following:

Weight loss.
Reluctance to eat.
Increased urine production.
Altered drinking habits: increased thirst (resulting from increased urine production) may drive your cat to drink in unusal places, such as from a pond or even from the toilet.
Gingivitis.
Vomiting.
Pale gums.
Bad breath.
Poor coat condition.
Depression and lethargy.

In many cases, the underlying disease that is responsible for renal failure remains unknown, but the following are all possible causes:

Development problems affecting the kidneys, called congenital renal conditions, that are present at birth (these are uncommon).
Chronic interstitial nephritis, or inflammation of the internal structure of the kidneys. This is a progressive disease, thought to be one of the more common causes of renal failure in older cats. Its cause is not fully understood.
Bacterial infection of the kidneys.
An inflammation of the blood filtering parts of kidney nephrons called glomerulonephritis, which is the result of certain complex immune system processes.
Cancer of the kidneys, especially lymphomas.
Amyloidosis: this affects kidney tubules, and may occur due to long-term immune system reactions to diseases of other body parts.
Feline infectious peritonitis.
Damage to the kidneys as a result of poisoning, such as antifreeze.
Obstruction to the normal flow of urine - for example, by uroliths in a male cat - causing a pressure build up in the kidneys that is damaging to the nephrons.
Direct damage to the kidneys, as a result of severe trauma.
The kidneys take about 25 percent of the blood pumped from a cat's heart, and renal failure may occur due to any disorder - such as severe dehydration - that reduces the blood supply to the kidneys.

Renal failure may be termed acute or chronic. In acute renal failure, a significant number of nephrons all stop working at the same time, as may occur in sudden urinary blockages. Chronic renal failure occurs more gradually due to progressive underlying diseases, and is the most common type of renal failure to affect cats.

Anatomy of a Cat's Kidney

A cat's kidneys are bean-shaped organs. Blood enters through the renal artery, is filtered within the kidney tissue and leaves through the renal vein. The urine produced by this process passes through the nephrons, then from the kidney to the bladder through the ureter.

Renal failure is a life-threatening condition. The long-term outlook for most cats with chronic renal failure is poor, but many can enjoy a good quality of life if treatment is initiated promptly, and is diligently carried out by the cats' owners.

All cats are at risk. However, the syptoms of renal failure are commonly seen in older cats, in whom the diseases responsible for the condition may have been established for years.

If your cat exhibits any of the symptoms described, take him to your vet as soon as possible. Your vet will consider the history of your cat's symptoms and will examine him thoroughly. He or she is likely to pay particular attention to feeling the size and shape of his kidneys through palpating his abdomen as, with renal failure, the kidneys may be enlarged, or small and shrunken.

Your vet will also carry out blood tests (in particular to look for raised levels of urea, a waste product of protein processing within the body), and may also carry out urine tests, Xray and ultrasound investigations. In exceptional cases, a biopsy of a kidney may be taken for examination.

WARNING: If your cat is known to suffer from renal failure but suddenly shows new symptoms, contact your vet immediately. Other conditions, which would be deemed trivial in a healthy cat, could seriously affect his renal problems and will require prompt and aggressive treatment.

In most cases of renal failure the cause is not identified, so your vet may only be able to begin treatment aimed at alleviating the symptoms:

Intensive care - If your cat is very ill, your vet will admit him as an in-patient until he is fit enough to be nursed at home. If your cat has stopped drinking and is dehydrated, he will need fluids via an IV drip.
Dietary management - A cat who has renal failure may benefit from alterations in the protein, fat, mineral and vitamin levels in his diet. Your vet will put together a feeding plan (including times of meals), which is likely to include prepared foods formulated for use in the management of renal failure. If your cat's appetite is depressed, you may need to encourage him to eat.
Medication - The use of specific medications may help to resolve any associated problems such as vomiting, anemia, and lack of appetite.
Chemotherapy - This is an option for cats who are suffering from lymphoma. A cat with chronic renal failure will require treatment for life. Initially, when symptoms are mild, this may simply involve changes to his diet. As the underlying cause of his renal failure progresses, his treatment is likely to become more involved, and your vet will want to monitor his condition on a regular basis. This may involve repeated blood or other tests.

At home, you must ensure that your cat has permanent access to fresh water. Your vet may suggest adding water to your cat's food or offering him broth or even milk if he is able to digest it, to encourage his voluntary fluid intake.

You must also help your cat to lead a stress-free life, by trying to prevent him over-exerting himself and keeping him warm (but not hot). And by all means, keep your cat indoors.

Outstanding and Comprehensive Feline Renal Disease Link for Additional Information:

Feline Chronic Renal Failure Information Center

Page URL: http://www.sniksnak.com/cathealth/renal.html

Reference Resources:
Cat Doctor, Mark Evans, B Vet Med MRVCS