Transfusion Reactions in Dogs

This capsule is part of the WSAVA Global Edition of Clinician’s Brief.

This retrospective study of 935 transfusion events in 558 dogs sought to evaluate the effect of premedication with antihistamines or corticosteroids on transfusion reactions (TRs) within 24 hours after blood transfusions in dogs. Authors also reported on other factors associated with acute TRs. There were 144 acute TRs in 136 dogs. The most common TRs reported were fever alone (53%) and vomiting alone (18%). TRs were not associated with age, sex, weight, or premedication. Type of blood product used was significantly associated with TR, with packed red blood cells most likely associated and plasma least likely. There were significantly fewer reactions associated with transfusions administered during the perioperative period. The presence of immune-mediated disease in patients receiving transfusion was significantly associated with TRs. Six dogs died as a result of TRs (4% of reactions). Dyspnea, noted in 10 transfusions (7% of reactions), was seen in all reactions that resulted in death. Tachycardia and acute hemolysis were each noted in 3% of cases. Allergic reactions, which comprised 9% of cases, were characterized by facial swelling, urticaria, or pruritus. Overall TR occurrence was not altered with premedication, but diphenhydramine decreased acute allergic reaction incidences. Steroid premedication was not of benefit in TRs but was associated with an increased risk for dyspnea. This study reported the first possible cases of canine transfusion-related acute lung injury (TRALI, the leading cause of transfusion-associated mortality in humans) in the literature. 

With the advancement of transfusion medicine in veterinary medicine, we tend to forget 2 important facts: first, transfusions are still associated with serious side effects; second, our methods of preventing these are poorly effective and have not changed much in the past decades. This study reminds us that TR prevalence is considerable, and it clearly shows that what we are doing to prevent TRs is not enough and is rarely effective. The authors parallel their results with what has been published in human medicine and point out, correctly, future directions for research. As with any excellent paper, after reading this study, one is left with many questions. For example, as found in humans, would age of the blood products be related to TR incidence? And what about late TRs—what kind of associations could we find? These and many other questions should be addressed in future prospective studies. Lastly, the authors are to be applauded because they provided the first evidence that TRALI exists in dogs. Working in the critical care environment, I was always puzzled by the fact that TRALI has never been reported before, especially after having cases that shared similar clinical and radiological signs to those reported in humans.—Nuno Felix, DVM, MS