Animal erythrocytes have cell surface antigens that undergo polymorphism and give rise to blood types. Antigens from the human ABO blood group system are also found in apes and Old World monkeys, and the system traces back to the origin of hominoids. Other animal blood sometimes agglutinates (to varying levels of intensity) with human blood group reagents, but the structure of the blood group antigens in animals is not always identical to those typically found in humans. The classification of most animal blood groups therefore uses different blood typing systems to those used for classification of human blood.
Two categories of blood groups, human-type and simian-type, have been found in apes and monkeys, and can be tested by methods established for grouping human blood.
The rhesus system is named after the rhesus monkey, following experiments by Karl Landsteiner and Alexander S. Wiener, which showed that rabbits, when immunised with rhesus monkey red cells, produce an antibody that also agglutinates the red blood cells of many humans.
Data on blood groups of chimpanzees, baboons, and macaques. Two complex chimpanzee blood group systems, V-A-B-D and R-C-E-F systems, proved to be counterparts of the human MNS and Rh-Hr blood group systems, respectively. Two blood group systems have been defined in Old World monkeys: the Drh system of macaques and the Bp system of baboons, both linked by at least one species shared by either of the blood group systems.
Over 13 canine blood groups have been described. Eight DEA (Dog Erythrocyte Antigen) types are recognized as international standards. Of these DEA types, DEA 4 and DEA 6 appear on the red blood cells of ~98% of dogs. Dogs with only DEA 4 or DEA 6 can thus serve as blood donors for the majority of the canine population. Any of these DEA types may stimulate an immune response in a recipient of a blood transfusion, but reactions to DEA 1.1+ are the most severe.