Blood transfusions save lives but are not without risk. Dr. Shauna Blois will test the effectiveness and safety of a blood filtration technique aimed at preventing transfusion reactions that occur in up to 13% of dogs receiving blood products. Leukoreduction (LR) removes white blood cells and some of their by-products from blood products using a special filtration set. Patients receiving LR blood transfusions may have fewer transfusion reactions including less inflammation, possibly leading to improved outcomes. This clinical trial will compare the inflammatory response of patients receiving LR to non-LR patients and monitor outcomes in critically ill dogs.