Chronic renal failure in cats - what is it?

Chronic kidney disease in cats, also called chronic renal disease or chronic renal failure (“CRF”), means that the kidneys are gradually and irreversibly deteriorating. This condition is very common in older cats and certain breeds (such as Maine Coon, Persian, Siamese, Burmese - but all breeds can be affected). CRF can occur at any age, but it is usually age related deterioration to the kidneys afflicting older cats.

There are tiny structures in the kidney called nephrons which eliminate waste products and regulate electrolytes in the body. When these nephrons lose function then CRF results and waste products and electrolytes can no longer be processed effectively. As the kidneys deteriorate anemia, electrolyte imbalances and blood pressure problems may also occur.

Functions of the kidneys

  • Filtering and removing waste products from the body (primarily creatinine and urea)
  • Regulating the amount of water in the blood as well as regulating electrolytes (potassium, calcium, sodium, phosphorus)
  • Secreting a hormone called erythropoietin which helps stimulate bone marrow to produce red blood cells
  • Production of an enzyme called renin which controls blood pressure
  • Production and concentration of urine

Symptoms of failing kidneys

  • Increased thirst
  • Excessive urination
  • Loss of appetite
  • Nausea
  • Vomiting
  • Weight loss
  • Emaciation
  • Poor hair coat
  • Constipation (secondary to dehydration)
  • Dehydration


Your veterinarian will recommend both blood and urine tests to be performed to aid in the diagnosis of CRF. A urinalysis will be performed to determine if the cat’s urine is dilute which indicates that the kidneys are not actively concentrating urine and passing waste materials. Blood tests will determine levels of creatinine and blood urea nitrogen (“BUN”) as well as assess other components in the blood. An elevated creatinine level with dilute urine is a sign of kidney function loss.


Unfortunately there is no cure for CRF but the condition can be managed for a period of time. The major factor of CRF management is to control the amount of waste products that are passing through the kidneys. This can be achieved through a combination of diet, medication and hydration therapy (diuresis).


CRF is a progressive terminal disease. With proper treatment in managing this disease, the cat may have from months to years of quality life. As the cat’s caregiver, you can determine with your veterinarian when the quality of life has deteriorated to the point at which prolonging life is no longer helpful.

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