Renal failure, especially CRF (Chronic renal failure), is a fairly common condition in older cats and dogs. The kidneys become less and less efficient at removing wastes[1] from the blood.

CRF can sometimes be mistaken for diabetes, since polyuria and polydipsia can occur in both; this may lead to incorrect treatment and progression of the renal failure[2][3].

Diabetes can affect all bodily organs. Many humans with long-term diabetes have some problems relating to the kidneys, including diabetic nephropathy. There are many people who are renal dialysis patients and on renal transplant lists who are also diabetes patients.

When CRF occurs in a diabetic pet, things can get tricky, since diabetes and CRF can complicate each other:

  • CRF and diabetes both require special dietary considerations, but they conflict[4].
  • glycosuria can lead to urinary tract infection, raising BG levels.
  • prolonged hyperglycemia can lead to diabetic nephropathy.
  • CRF can make it harder to regulate blood glucose levels.
    Insulin is metabolized mainly through the liver and kidneys[5][6]. The term used in references such as Physicians' Desk Reference and other medication information is reduced renal clearance, for the kidneys, reduced hepatic clearance for the liver.
    When the system processes insulin (and other medications) at a slower than normal rate, they remain in the system longer[7]. In the case of insulin, a previously acceptable dosage may lead to hypoglycemia, because it takes longer for the kidneys and/or liver to render it useless. Renal problems seem to affect the clearance of insulin more than disorders of the liver[8].
  • CRF and high blood pressure are both possible complications of diabetes, and of each other. See blindness.

See also urination, renal threshold, low-carb diet, medium-carb diet, urinary tract infection, kidney infection.

Further ReadingEdit





  1. FDMB--CRF/Renal Failure Discussion
  2. Polydipsia & Polyuria in
  3. Polydipsia & Polyuria in
  4. BD Diabetes-Diet & Exercise for the Diabetic Cat
  5. Metabolism of Insulin Through Liver & Kidneys
  6. Merck Veterinary Manual-Drug Clearance-Elimination
  7. Merck Veterinary Manual-Drug & Metabolite Excretion
  8. InChem-Insulin-Metabolism-6.4
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