Urinary biomarkers of renal function in dogs and cats: a review

Kidney diseases commonly affect dogs and cats. Early diagnosis of renal impairment may be challenging even when urinalysis is used to provide additional information. Serum creatinine concentration is often used in the diagnosis, but it is a relatively insensitive marker of renal function. Particular attention is aimed at the investigation of certain molecules that may occur in urine at elevated levels as a result of glomerular or tubular dysfunction. These changes may be found before the increase of serum creatinine levels. This review article summarises reports of urine biomarkers and their utility in detecting early kidney disease in dogs and cats. Detection of multiple urinary biomarkers in diagnosis of acute kidney injury and chronic kidney disease may increase specificity and sensitivity. Early diagnosis of reduced renal functional mass allows early therapeutic interventions which may decrease morbidity and mortality.