Serum symmetric dimethylarginine, creatinine, and blood urea nitrogen at admission as predictors of survival in dogs with chronic kidney disease

Chronic kidney disease (CKD) is among the most common conditions in cats and dogs, often resulting in irreversible loss of renal function and/or structure, and increased mortality. The present study aimed to evaluate prognostic markers and long-term survival in dogs with CKD. A total of 81 dogs with CKD and 20 healthy controls were included in the study. Clinical examination, chemical analysis, hematological analysis, urine analysis, and renal resistive index were performed at admission. Dogs included in the study were classified according to the International Renal Interest Society (IRIS) criteria (2016) and monitored for 396 days. Among the CKD cohort, 63% survived while 37% died, with a mean survival time of 91.46 ± 19.57 days. Admission serum concentrations of blood urea nitrogen (BUN), creatinine (Cr), and symmetric dimeth ylarginine (SDMA) were identified as significant prognostic indicators in dogs with CKD. Survival rates were 78% for stage 1 and 15% for stage 4 CKD (odds ratio 2.22, 95% CI: 0.431–11.497). No significant difference in survival time was observed between early and advanced CKD stages, and elevated serum SDMA concentrations were not associated with sur vival duration. Increased serum concentrations of Cr, BUN, and SDMA at admission were significant in non-survivor dogs compared to survivors. However, serum SDMA demonstrated the highest discriminatory performance among the evaluated biomarkers in ROC analysis, although its ability to predict long-term survival was limited. Although the risk of death was ap proximately twofold higher in advanced CKD stages, long-term survival did not differ significantly between disease stages.