Blood type and transfusion risks in cats being evaluated as blood donors at 2 italian university bllod bancks

Cats have naturally occurring alloantibodies, therefore they should be transfused with blood of the same blood type A, B, or AB to avoid major and minor transfusion reactions. The purpose of this study was to describe the blood type distribution in cats presented at 2 university blood banks in northern (Milan) and central (Perugia) Italy between September 2010 and June 2013 as potential blood donors, and to assess the risk of major and minor transfusion in this population. Blood typing was per- formed using an immunochromatographic cartridge method. A total of 357 cats belonging to 15 different breeds, 158 female (45.3%) and 191 male (54.7%), with a mean age of 3.8 years (SD`2.9) was evaluated. Of these 90.5% (322) were blood type A, 5.6% (20) type B and 3.9% (14) type AB. The majority of the cats (195; 54.6%) were European Domestic Short Hair (EDSH), of which 92.3% (180) were type A, 5.1% (10) type B and 2.6% (5) type AB, 75 (21%) were Maine Coon (MC) cats, and 100% of these were blood type A. The estimated frequencies of transfusion reactions following an unmatched transfusion between EDSH (donors and recipients), MC (donor and recipients), EDSH donors and MC recipients and MC donors and EDSH recipients were 4.8%, 0%, 0%, and 5.1% for major reactions and 7.2%, 0%, 7.7%, 0% for minor transfusions reactions. The frequencies of the 3 feline blood types in cats in this study are comparable to those previously reported, with a predominance of blood type A. All MC cats in the study were blood type A. In a population of blood donors including EDSH and MC the risk of a transfusion reaction could be in excess of 5% if the donors and recipient are not blood typed. Blood typing and cross-matching should there- fore be performed before transfusion in order to minimize the risk of transfusion reactions.