Background: Hyperlipasemia has been reported in dogs with acute kidney injury (AKI) but associations with AKI severity, hemodialysis (HD) treatment, and outcome have not been extensively evaluated.Objectives: Investigate the prevalence and clinical relevance of hyperlipasemia in dogs with AKI, treated with and without HD. Animals: Client-owned dogs (n = 125) with AKI. Methods: Retrospective data extraction from medical records, including signalment, cause of AKI, duration of hospitalization, survival, plasma creatinine concentration, and 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6 0 -methyresorufin) ester (DGGR) lipase activity at admission and throughout hospitalization.Results: A DGGR-lipase activity >3Â the upper reference limit (URL) was found in 28.8% and 55.4% of dogs at admission and during hospitalization, respectively, but only 8.8% and 14.9% of dogs, respectively, were diagnosed with acute pancreatitis. Hyperlipasemia >10 Â URL was observed in 32.7% of dogs during hospitalization.The DGGR-lipase activity was higher in dogs with International Renal Interest Society (IRIS) Grades 4-5 than Grades 1-3, but correlation between DGGR-lipase activity and creatinine concentration was poor (r s = .22; 95% confidence intervals [CI], 0.04-0.38). Treatment with HD was not associated with DGGR-lipase activity independent of IRIS grade. Survival to discharge and 30 days after admission was 65.6% and 59.6%, respectively. High IRIS grades (P = .03) and high DGGR-lipase activity at admission (P = .02) and during hospitalization (P = .003) were associated with nonsurvival.Conclusions and Clinical Importance: Hyperlipasemia is frequent and often marked in dogs with AKI despite only a minority being diagnosed with pancreatitis. Hyperlipasemia is associated with AKI severity but not independently with HD treatment.High IRIS grade and hyperlipasemia were associated with nonsurvival.