Creatinine-Derived Composite Indices for Improved Mortality Prediction in Dogs with Acute Pancreatitis

In dogs, acute pancreatitis (AP) is frequently associated with systemic inflammation and renal dysfunction, both of which may adversely affect outcomes. This retrospective cohort study evaluated the prognostic utility of the creatinine-to-albumin ratio (CAR), neutrophil–creatinine index (NCI), and neutrophil-to-lymphocyte ratio (NLR) for predicting in-hospital mortality. One hundred and thirty-four dogs diagnosed with AP and forty healthy controls were included. All indices were calculated from routine hematological and biochemical data obtained at admission before treatment initiation. Prognostic performance was assessed using logistic regression, receiver operating characteristic (ROC) curve analysis, and comparison of ROC curves using the DeLong test. The results showed that all indices were significantly higher in dogs with AP than in healthy controls and were further increased in non-survivors. The mortality prevalence increased significantly across CAR and NCI percentiles, whereas no consistent association was observed for the NLR. CAR (AUC = 0.747, cutoff > 0.48, OR = 5.63) and NCI (AUC = 0.747, cutoff > 26, OR = 7.08) showed the highest discriminatory ability, followed by serum creatinine (AUC = 0.734, cutoff > 1.19 mg/dL, OR = 6.08). A ROC curve comparison revealed no significant differences between creatinine and CAR (p = 0.479), creatinine and NCI (p = 0.712), or CAR and NCI (p = 0.982). However, the NCI demonstrated significantly greater discriminatory performance than the NLR (AUC = 0.619; p = 0.021). In multivariable analyses, CAR and NCI remained independently associated with the outcome after adjustment for the NLR. These findings suggest that CAR and NCI may provide useful prognostic information in dogs with acute pancreatitis. Because they are derived from routinely available laboratory parameters, they may represent practical tools for early risk stratification at hospital admission.