Diagnostic validation of the urine albumin-to-creatinine ratio for early renal disease in healthy dogs and dogs with chronic kidney disease

Importance: This paper highlights the urine albumin-to-creatinine ratio (UAC) as a valuable biomarker for the early detection of chronic kidney disease (CKD) in dogs. The UAC effectively distinguishes between healthy dogs and those with CKD, particularly in the early stages, and enhances diagnostic accuracy when used alongside other renal biomarkers.

Objective: To evaluate the utility of the UAC as a biomarker for early CKD diagnosis in dogs and examine its correlation with other renal biomarkers in a large-scale clinical study.

Methods: This study included 99 healthy dogs and 122 dogs with CKD. The UAC and other renal biomarkers were measured and evaluated in healthy dogs and those with CKD and categorized according to the staging criteria of the International Renal Interest Society (IRIS).

Results: Dogs with CKD had significantly higher UACs than healthy dogs (p < 0.05). The UAC correlated with the IRIS stages and other renal biomarkers (p < 0.05). Receiver operating characteristic curve analysis yielded an area under the curve of 0.817 (p < 0.05) for the UAC, with a cut-off value of 19.20 mg/g, showing 72% sensitivity and 71% specificity. A "grey zone" diagnostic window for early-stage CKD was introduced.

Conclusions and relevance: The UAC is effective for the early diagnosis of renal disease in dogs. The UAC can differentiate between healthy dogs and those with CKD at IRIS stage 1. The diagnostic value is enhanced when used alongside other renal biomarkers, allowing for more specific guidelines for pet owners and veterinarians. This large-scale study addresses the limitations of previous research conducted on small clinical samples.