Correlation of renal function biomarkers in the first diagnostic approach to canine chronic kidney disease

Objective. To determine the correlation of kidney function biomarkers at the first evaluation in dogs with different risk factors identified for developing chronic kidney disease (CKD). Materials and methods. A descriptive, prospective study of cases and controls of 388 animals, divided into five groups: control group (CG), and four groups of potentially kidney-diseased dogs (pCKD) was carried out. Clinical history, physical examination, body condition score (BCS), complete blood count, biochemical profile with symmetrical dimethylarginine (SDMA), urinalysis, urine protein/creatinine ratio (UPC), and systemic blood pressure were analyzed. Non-parametric statistics were used, and data were expressed as medians and percentiles; for BCS, Xi2 was used. For biomarkers, Spearman's correlation was performed. Results. For SDMA and serum creatinine (sCr), a moderate correlation was observed for pCKD (r=0.69, p<0.001). Significant differences were observed in the variables age (p=0.002) and BCS (p<0.001) between the CG and the pCKD. Animals with mild azotemia (sCr 125-250 mu mol/L) and/or with an SDMA value of 18-35 mu g/dL, with or without proteinuria, had a greater probability of presenting an increase in SDMA when the BCS was below 5/9 (OR=3.55, p=0.005). Conclusions. SDMA is a useful complementary biomarker in pre-azotemic stages and advanced stages where there is cachexia and sarcopenia. Biomarkers must be evaluated together to have a complete perspective of renal function in animals with risk factors for developing CKD.