Kidney (Renal) Disease

Kidney (renal) disease is one of the most common causes of illness in cats but it is not just older cats that are at risk, renal failure can strike at any time and the results can be devastating. As cat owners you need to know the subtle signs that tell us your cat may be in trouble.


The kidneys play an essential part in maintaining your cat’s health by removing waste products from the blood stream, but they are responsible for so much more!

The kidneys produce three important hormones:

I. EPO, which stimulates the bones to make red blood cells.
II. Renin (REE-nin), which regulates blood pressure.
III.The active form of vitamin D, which helps maintain calcium for bones and for normal chemical balance in the body.
The kidneys also regulate the quantities of sodium, phosphorus, and potassium in the bloodstream.

When your cat’s kidneys are compromised its body is thrown into turmoil.

Kidney failure is usually separated into two categories:

 acute renal failure – which usually develops quickly over a week or a month

  With early diagnosis, acute renal failure can be detected and managed’

 chronic renal failure – the gradual deterioration of the kidneys over a prolonged period of time.

 ‘chronic renal failure is an incurable condition that mainly affects older cats'


As kidney failure is a progressive disease, you may not pick up any symptoms in your cat until it is already quite ill. However, you may notice: 

 increased thirst and urination
• Subtle weight loss
 Decreased appetite
  Bad breath – drooling (caused by mouth ulcers)
  Increased sleeping patterns

Your cat may also begin to look scruffy as it grooms itself less.

As you can see the list of symptoms is diverse and can be attributed to many other illnesses. If your cat persistently shows any of these symptoms it would be wise to get her checked out.


The causes can be as varied as the symptoms and often remain unknown.

 Kidney infection
 Advanced dental disease
 Obstructions such as kidney stones or blocked bladder which can cause; Decreased blood or urine flow to the kidneys
 Ingestion of toxic substances, such as antifreeze, pesticides, medications and cleaning chemicals
• Polycystic kidney disease- genetic predisposition to the disease
 Age older than seven years
 Feline infectious Peritonitis (FIP)
 Feeding food high in phosphorus or increased levels of protein can increase the disease’s progression

Your cat may also begin to look scruffy as it grooms itself less.

As you can see the list of symptoms is diverse and can be attributed to many other illnesses. If your cat persistently shows any of these symptoms it would be wise to get her checked out.


The first thing your vet will do after taking a detailed
history is to perform a physical examination. Apart from
evaluating the general condition of your cat, these are some of
the signs your vet will be looking for:

 Low body temperature
 Poor body condition, weight loss, shabby coat
 Excessive skin tenting and dry gums showing dehydration
 Sharp or bad breath, possibly with ulcers in the mouth
 Pale gums
 Evidence of ocular haemorrhage or blindness associated with high blood pressure (hypertension)

It may also be possible for your vet to feel irregularities in the size and shape of the kidneys.

If your vet suspects your cat has kidney disease there are several tests which will help to differentiate the symptoms from other conditions and which will indicate how severe the kidney disease is.

These tests may include:

 Complete blood count (CBC)— to determine if there is  anaemia (too few red blood cells) or an increase in white blood cells which would indicate  infection, stress or inflammation.
 Chemistry profile with electrolytes
 SDMA testing
 Urinalysis with sediment exam—Examining a urine specimen, especially, prior to any treatment, is a simple and economical way to gauge urine quality.
 Urine protein to creatinine ratio test
 Diagnostic imagingX-rays and ultrasound to identify changes in the size, shape, of the kidneys and their plumbing may show a need for emergency treatment.
 Infectious disease testing—Routine testing of all sick cats for feline leukaemia virus (FeLV) and feline immunodeficiency virus (FIV) is advisable.


Once your vet has evaluated your cat he will decide how best to approach the treatment and management of your kitty. Each kidney patient will respond differently to treatment depending on the severity of the kidney disease present.

Acute kidney failure – if diagnosed and treated early enough it is sometimes possible to reverse acute kidney failure. Immediate medical attention is required to limit the amount of permanent damage to the kidneys. Your cat will probably be hospitalized be given intravenous fluid therapy and supportive renal medication. Sadly, there are cases in which the damage to the kidneys is so severe that nothing can be done to help the patient and euthanasia is the kindest option.

Chronic kidney failure - this is commonly seen in older cats (over 7 years) and depending on the general condition of your cat may be treated with supportive medication and fluid therapy.

Good nutrition is of immense importance in the management of the kidney patient. Prescription diets are available that are formulated to assist in the control of kidney disease in cats.

‘high quality medical evidence shows that diet is important to slow chronic kidney disease ‘

‘It’s recommended that all cats 7 years and older get a “senior screening” at their annual check-up in order to determine if your cat has kidney issues.’

Although it is possible to manage most chronic kidney disease patients it remains a difficult condition to control and in the case of acute kidney failure it can leave the owner devastated and the veterinary team feeling helpless. 


47 Kenilworth Road, Cape Town
Telephone: 021-671-5018