In the last several years, the debate over the use of hydroxyethyl starch (HES) solutions in veterinary medicine has intensified. In human patients, HES products now have a boxed warning recommending against their use in critically ill patients, based on evidence that they contribute to coagulopathy, acute kidney injury (AKI), and increased risk of mortality.1 In veterinary patients, no studies of AKI or outcome in clinical patients receiving HES have been performed. So, Hayes et al out of Ontario Veterinary College set out to determine if HES administration was associated with outcome or AKI in canine ICU patients in a study called "Retrospective cohort study on the incidence of acute kidney injury and death following hydroxyethyl starch (HES 10% 250/0.5/5:1) administration in dogs (2007-2010)." Because many of these patients would already be considered critically ill based on their admission to the ICU, a retrospective cohort study was designed with an illness severity measure included.