How to diagnose and manage Proteinuria in Feline Chronic Kidney Disease

Chronic kidney disease is commonly diagnosed in older cats. Following diagnosis, staging by serum creatinine and substaging by urine protein creatinine ratio and systolic blood pressure are important for appropriate monitoring and treatment.

Proteinuria is a negative prognostic indicator in cats with CKD and multiple studies have demonstrated that the magnitude of proteinuria is inversely proportional to survival. Identifying and managing proteinuria is therefore important. Assessment of proteinuria involves identification of its localisation, persistence and magnitude.

The origin of proteinuria can be pre-renal, renal or post-renal and it is considered persistent if detected at least three times, two weeks apart. Urine protein creatinine (UPC) ratio is the gold standard method of confirming and quantifying the magnitude of proteinuria.

Treatment is indicated in cats with a UPC>0.4 and centres on inhibition of the activated renin angiotensin aldosterone system using an angiotensin converting enzyme inhibitor (benazepril) or an angiotensin receptor blocker (telmisartan). Systemic hypertension should also be treated if present.