Management Of Kidney Failure in Cats

• Introduction

• Diet

• ACE Inhibitors

• Fluid Therapy

• Other Treatments

ACE Inhibitors Explained

ACE inhibitors, or Angiotensin Converting Enzyme inhibitors, to give them their full title, were first developed for use in man after it was found that they reduce excessive amounts of protein in the urine (which is thought to be toxic to the kidneys), reduce blood pressure, and increase lifespan. ACE inhibitors reduce the pressure within the glomerulus of the kidney (the kidney's filter) which is thought to slow down further damage to the kidney. One ACE inhibitor has now been licensed for use in the management of kidney failure in cats.

Cats with CKD tend to develop proteinuria (the presence of protein in the urine) and it has been found that the higher the level of proteinuria, the shorter the expected survival. ACE inhibitors have been shown to significantly reduce the level of proteinuria in cats, just as they do in humans, and treatment tends to improve survival.

Given that kidney failure cannot be cured, one of the most important aspects of treatment is to maintain the best quality of life for the patient. In clinical trials owners tended to report better quality of life in cats treated with an ACE inhibitor than those treated with just a kidney diet. Additionally appetite was often improved and, indeed, one ACE inhibitor has been shown to increase appetite, even in normal cats.

An additional benefit of ACE inhibitors is that they lower blood pressure. High blood pressure (hypertension) is found as a consequence of kidney failure in around 20% of CKD cats. 

ACE inhibitors are used to treat mild hypertension but additional anti-hypertensive drugs may be needed in CKD cats suffering from severe hypertension.