Early detection of chronic kidney disease (CKD) remains challenging, most likely due to the limited sensitivity of conventional renal biomarkers for identifying subclinical diseases. Kidney injury molecule-1 (KIM-1) is a biomarker for the detection of acute kidney injury; however, its potential role in canine CKD is unclear. This study aimed to evaluate plasma KIM-1 (pKIM-1) and urinary KIM-1-to-creatinine ratio (uKIM-1/uCr) as diagnostic biomarkers for stable CKD in dogs, with or without non-azotemic stages, and assess their correlations with conventional renal biomarkers. Ten healthy control dogs, 14 dogs with non-azotemic stable CKD, and 11 dogs with azotemic stable CKD were prospectively enrolled. Plasma and urinary KIM-1 concentrations were measured using canine-specific ELISA. Conventional renal biomarkers, including blood creatinine, blood urea nitrogen (BUN), symmetric dimethylarginine (SDMA), urine protein-to-creatinine ratio (UPCR), and urine specific gravity (USG) were also analyzed, and the diagnostic accuracy was assessed using receiver operating characteristic (ROC) curve analysis. Results showed that pKIM-1 levels and uKIM-1/uCr ratios were significantly higher in CKD dogs than that in healthy controls (P<0.05), regardless of the azotemia status. These markers showed moderate-to-strong positive correlations with conventional renal markers, including creatinine, BUN, SDMA, and the urine protein-to-creatinine ratio. The ROC curve analysis demonstrated precise diagnostic accuracy for stable CKD, including in non-azotemic dogs. In conclusion, plasma and urinary KIM-1 levels are promising biomarkers for the diagnosis of stable CKD in dogs, enabling earlier and more precise detection before azotemia development.

To Cite This Article: Yu SJ and Kim JH, 2026. Plasma and urinary kidney injury molecule-1 as early biomarkers for the diagnosis of stable chronic kidney disease in dogs. Pak Vet J. http://dx.doi.org/10.29261/pakvetj/2026.017