Normally an animal will not have antibodies against antigens present on the surfaceof its own red blood cells or against blood group antigens of that species unless they have been produced following pregnancy, a previous transfusion or a vaccine reaction. | Normally an animal will not have antibodies against antigens present on the surfaceof its own red blood cells or against blood group antigens of that species unless they have been produced following pregnancy, a previous transfusion or a vaccine reaction. |