What is the expected result of a blood transfusion from a type A cat to a type B cat, assuming neither has received a transfusion before?

The expected result of a blood transfusion from a type A cat to a type B cat is that an acute transfusion reaction will occur due to the presence of anti-A antibodies in the recipient's blood. Type B cats have naturally occurring antibodies against type A blood. When type B cats receive type A blood, these anti-A antibodies recognize the A antigens on the surface of the type A red blood cells as foreign and mount an immediate immune response against them. This immune response can lead to hemolysis (destruction of red blood cells), which manifests as clinical signs of an acute transfusion reaction.

Understanding blood type compatibility is crucial in veterinary medicine. Unlike in some other species where universal donors and recipients exist, cats have specific blood type systems, and mismatching can result in adverse reactions. In this case, a type B cat's immune system is primed to react negatively to type A transfusions, making it imperative to carefully match blood types prior to transfusion. This specific antibody-antigen reaction emphasizes the need for awareness of the blood type characteristics of cats to prevent transfusion-related complications.