Acute hemolytic transfusion reaction in an Abyssinian cat with blood type B

After receiving a transfusion with unmatched blood, an anemic Abyssinian cat developed an acute hemolytic transfusion reaction. Similar to many other purebred cats, the recipient had type B blood with strong serum anti-A alloantibodies, whereas the donor had blood type A. Subsequent transfusions with type B blood proved effective and without adverse reactions. This case of a clinical A-B incompatibility reaction emphasizes the need for blood typing and/or crossmatching prior to transfusing cats.