Kidney failure is one of the most common health problems suffered by cats, particularly as they grow older.
There are two types of kidney disease:
Chronic renal failure
Chronic renal failure can occur in cats of any age, but is most commonly seen in middle to old-aged cats, and it becomes increasingly common with age. It has been estimated that around one in five cats over 15 years of age has renal failure. In general, chronic renal failure is seen about three times more frequently in cats than it is in dogs.
Acute kidney disease
This refers to sudden damage to the kidneys and is usually as a result of trauma, posioning, infection or blockages caused by lower urinary tract disease. Signs are often sudden and severe and unless immediate treament is sought, the condition can rapidly become fatal. Unfortunately acute kidney disease may often lead to chronic kidney disease.
What do the kidneys do?
The kidneys are vital organs that filter excess fluid and waste products from the body. Blood flows through the kidneys where filtering units called nephrons remove or conserve water, minerals and electrolytes from the body, keeping them in balance. The extra fluids and harmful waste products that the kidneys filter out of the blood are eliminated in the urine. The kidneys have additional important functions including the production of certain hormones and regulating blood pressure. So when a cat’s kidneys are diseased and not functioning properly, it has a great impact on overall health and well-being.
Kidney disease in cats
Kidney (renal) disease in cats is normally a gradual process that results in irreversible damage to the kidneys over time. The decrease in healthy, functioning kidney tissue leads to the loss of water and important substances the body needs, and causes accumulation of toxins and excess minerals that the body would normally get rid of.
Kidney disease is one of the most common health problems as cats age.
Causes of kidney disease
Kidney disease may be brought on by underlying causes, such as:
•Metabolic and immune disorders
•Genetic disease
•Infections or chronic inflammation
•Cancer
Regardless of the underlying cause, kidney disease tends to progress, or worsen over time, and leads to the build up of harmful waste products in the body and an imbalance of minerals, such as phosphorus.
When the kidneys do not function properly, phosphorus is not eliminated as it normally would be, resulting in increased phosphorus levels in the body. Increased phosphorus levels in the body can lead to mineral deposits in the kidneys and other organs and worsen the kidney disease. The control of phosphorus is one of the most critical factors in the ongoing management of kidney disease, helping protect the kidneys and other organs from further damage.
Symptoms of kidney disease
The signs of kidney disease are often non-specific and subtle, especially early in the disease. These symptoms are generally related to the under-functioning kidneys’ ability perform important functions such as eliminating waste products and maintaining water and mineral balance.
Cats often become dehydrated and lose weight because they lose their appetite. Changes as subtle as a drop in weight since the last visit to the vets or your cat making more trips to the water bowl or litter box may be the only initial signs of an underlying problem.
Typical symptoms of kidney disease in cats may include:
•Reduced appetite
•Increased thirst/urination
•Sleeping more
•Decreased activity
•Weight loss
Some cats may suddenly appear to become ill but have had kidney disease for some time, showing few or very subtle signs of a problem. This is why it’s so important to have your older cat regularly evaluated for normal kidney function.
Because of the tremendous reserve of the kidneys cats will not show outward signs of disease until 75% or more of the kidney function is lost
How is kidney disease diagnosed?
Kidney disease can be diagnosed through examination and testing by your vet.
To diagnosis kidney disease, urine and blood samples are taken for laboratory testing. These tests will identify if there are problems with the kidneys’ ability to concentrate the urine properly and if there are waste products building up in the blood, as well as the presence of mineral and electrolyte imbalances. Additional tests such as blood cell counts and measuring blood pressure can identify other problems related to kidney dysfunction.
Because the early signs of kidney disease are often very subtle and cats are good at hiding illness in general, it’s important to have your cat checked periodically for kidney disease and other geriatric diseases.
Ideally, cats 7 years of age or older should be screened for any early indications of kidney dysfunction on at least a yearly basis. The earlier kidney disease is diagnosed the earlier steps can be taken to improve and prolong your cat’s life.
An excellent guide which explains what a diagnosis of kidney failure means and how best to manage this. All aspects of care are discussed with information on all of the available treatment options. The case study included shows how treatment can be highly successful, even in very serious cases, with many patients living for years after a diagnosis of kidney failure is made.

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Claire