Introduction

Xenotransfusion is the transfusion of blood from one species to another. Despite set guidelines for transfusing blood products to cats, and the availability of allogenic feline blood (AFB), there are various circumstances when canine blood is transfused to cats. The objective of this study was to compare a group of anemic cats that received canine xenotransfusion with a group of anemic cats treated with matched AFB. The study aims to describe the clinical situations in which transfusions were used, assess acute and late transfusion-related adverse effects (TRAE), and evaluate survival and long-term outcome.

Methods

The medical records of cats treated with xenotransfusion or AFB (years 2013–2021), were retrospectively reviewed.

Results

The study included 105 cats who received xenotransfusions and 206 cats who received AFB. The most common reason for anemia in the study and control groups were hemorrhage 61/99 (62%) and hemolysis 74/200 (37%), respectively (P<0.001). Eighty percent (63/79) of cats who suffered anemia due to decreased production received allotransfusions while only 20% (16/79) received xenotransfusions (P<0.001). In the study group, 55% of cats survived to discharge vs. 73% of the control group (P=0.007). Thirty-day survival rate was 90% and 87.5% in the study and control groups, respectively (P=0.850). The most common reason for xenotransfusion was financial constraint (49%). Mean PCV following transfusion was significantly higher in the study group compared to the control (22% vs. 18%, P<0.001) and still significantly higher 48–96 hours post-transfusion (23% vs. 18%; respectively, P<0.001). Cats in the study group experienced significantly more TRAE (37.1%), compared to the control group (19.4%) (P=0.0010) and significantly more delayed hemolytic transfusion reactions (85% vs. 42.5% of TRAE, respectively, P<0.001). while the control group suffered significantly more acute transfusion reactions (60% of TRAE), compared to the study group (20% of TRAE), (P<0.001). There were no differences in survival to discharge between cats that experienced TRAE and those that did not. Non-survivors had higher creatinine concentration pre- and post-transfusion (P=0.008, P=0.037, respectively).

Conclusion

Xenotransfusions might be a life-saving procedure in emergency situations when AFB is not available. The long-term survival of cats treated with xenotransfusion and survive to discharge is excellent.

E-mail: maria.elkin@mail.huji.ac.il