You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

The use of ACE inhibitors in the management of renal failure is regarded as controversial by many authors. However, initial studies in dogs are reported to show an improvement in proteinuria

Activation of the renin-angiotensin-aldosterone axis is a well documented in  renal failure. Angiotensin II is increased in concentrations and it causes a variety of effects * :

1. In the kidneys it has several effects including :

• Increases sodium reabsorption  
• Arterioconstriction (especially efferent vessels)
• Mesangioconstriction
• Stimulates secretion of transforming growth factor
• Stimulates secretion of prostaglandin
• Increases blood flow to juxtaglomerular nephrons 
• Induce glomerulosclerosis
• Induce infiltration/fibrosis of mesangium and tubulointerstitial tissues

     2.   Systemically :

• Vasoconstriction causing increased blood pressure
• Increases aldosterone secretion - causes retention of sodium

Many of these changes are potentially detrimental to the kidney, so preventing the conversion of angiotensin I to angiotensin II would therefore be of potential benefit. Initial studies with ACE inhibitors in dogs have shown :

• In dogs with heart failure and having increased plasma creatinine concentrations, ACE inhibitors improved glomerular filtration rate (GFR)
• Initial studies into the use of ACE inhibitors in dogs with moderate renal failure failed to produce any untoward side-effects
• In dogs with uninephrectomy and diabetes ACE inhibitors reduced proteinuria and interstitial changes
• Studies in dogs with protein-losing nephropathy have showed a tendency towards decreased proteinuria

There are two main concerns about the use of ACE inhibitors in renal failure :

1. ACE inhibitors are excreted via the kidneys so their safety in renal failure must be established
2. ACE inhibitors can cause hypotension - and there is a potential risk of inducing acute kidney injury (renal failure) in patients with existing chronic renal failure if renal perfusion falls suddenly

One ACE inhibitor (Fortekor) is licensed for use in cats (only) to reduce proteinuria - but it is essential to monitor renal function to avoid precipitation of acute kidney injury.

* After Meyer H.P. NAVC Proceedings (2000)

Updated January 2016