Acute Azotemia as a Predictor of Mortality in Dogs and Cats

Background Acute kidney injury ( AKI ) has been shown to be a predictor of mortality in human medicine. Published studies in the veterinary literature evaluating relative changes in serum creatinine concentration as a prognostic factor are limited. Objective To evaluate an AKI grading system based on serum creatinine concentration to determine if it correlates with outcome prediction in dogs and cats. Animals Six hundred forty‐five dogs and 209 cats that had at least 2 serum creatinine concentration measurements measured within 7 days. Methods Retrospective study. Dogs and cats with an initial serum creatinine concentrations of ≤1.6 mg/dL and that had more than 1 concentration measured within 2, 3, and 7 days were placed into levels (0–2) based on absolute changes. Mortality then was determined at 30 and 90 days. Results Based on odds ratios calculated with a 95% confidence interval, dogs placed in level 1 within 2 days were approximately 3 times more likely to die within 90 days. Dogs placed in level 2 within 2, 3, or 7 days were approximately 3 times more likely to die within 30 or 90 days. Cats placed in level 2 within 3 or 7 days were approximately 3 times more likely to die at 30 days and 4 times more likely to die if placed in this level within 7 days. If placed in level 2 within 2 or 3 days, cats were approximately 3 times more likely to die within 90 days. Conclusions and Clinical Importance Detecting increasing severity of azotemia helps predict mortality in dogs and cats.