Management Of Kidney Failure in Cats

• Introduction

• Diet

• ACE Inhibitors

• Fluid Therapy

• Other Treatments

Kidney Diets Explained

Special 'renal' diets are often prescribed for cats with chronic kidney disease (CKD). There is now plenty of good scientific evidence to show that CKD cats eating these diets live longer (on average twice as long) as those not fed the diets. The diets should be introduced gradually to encourage acceptance by the cat. Renal diets are formulated to contain:

Restricted protein
Waste products are produced by the body as protein is converted into energy. So, by reducing the amount of protein in the diet, so the amount of waste needing to be processed by the ailing kidneys can be limited or reduced. This in turn can reduce the clinical signs associated with the build up of waste products in the body (called uraemic signs), such as vomiting, loss of appetite, anaemia and lethargy. The benefits of protein restriction in reducing these clinical signs have been supported by scientific studies performed both in cats and other species.

Whether dietary protein restriction actually has any impact on the progression of renal failure in cats is still a very controversial area.

Reduced phosphorus/phosphate
Phosphorus is an important mineral usually found in nature combined with oxygen as phosphate. Whilst an important component of cells and bone in the mammalian body, too much phosphate contributes towards hyperparathyroidism (over production of  parathyroid hormone which regulates the amount of calcium and phosphorus in the body). In one scientific study looking at cats with naturally occurring renal disease, improved survival times were seen in those fed a phosphate restricted diet.

Increased potassium and vitamin B
Prescription renal diets are supplemented with potassium and water soluble vitamins (B and C vitamins) which CKD cats are vulnerable to losing in their urine. Potassium deficiency is covered in greater depth in the section: Managing potassium deficiency.

Reduced sodium
Renal diets usually have lower levels of sodium, which may help to reduce the risk of systemic hypertension (high blood pressure) from developing.

Palatability and calorie content
Increased palatability and calorie density helps CKD cats with a poor appetite to maintain a normal body weight.

Acid-base balance
Renal diets are formulated to help prevent acidosis (excess blood acidity - a common consequence of kidney disease) from developing in cats with CKD.

Additional dietary manipulations
Renal diets often have supplemented fibre which helps to reduce absorption of protein breakdown products across the bowel. Levels of fatty acids (e.g. omega 3 polyunsaturated fatty acids) are also often supplemented as this has been shown to slow the progression of renal disease in other species.