Canine blood groups

There are 8 major blood groups in the dog, labeled as DEA (dog erythrocyte antigen) 1 to 8. These are illustrated in the table below. The major antigens are DEA 1.1 and DEA 1.2. Dogs can be positive for either (not both) DEA 1.1 or 1.2 or are negative for both. Naturally occurring antibodies occur in 20% of DEA 3-negative, 10% of DEA 5-negative, and 20-50% of DEA 7-negative dogs.

Acute hemolytic transfusion reactions only occur in DEA 1.1 and 1.2 negative dogs. As these dogs do not have naturally occurring antibodies, a reaction will only be seen after sensitization of the dog through exposure to DEA 1.1 or 1.2 positive blood (antibody production takes 7-10 days after exposure). The normal lifespan of compatible transfused erythrocytes in dogs is approximately 21 days. In an acute hemolytic transfusion reaction, the lifespan of incompatible transfused erythrocytes ranges from minutes to 12 hours. Although DEA 3-, 5- and 7-negative dogs do have naturally occurring antibodies to DEA 3, 5 and 7 positive red cells, these blood groups do not incite severe hemolytic reactions. Rather, transfusion of incompatible blood is hemolysed more rapidly (within 4 to 5 days) than compatible blood would be (so-called delayed hemolytic reaction). Therefore, crossmatching in dogs does not need to be done on the first transfusion. Neonatal isoerythrolysis has been reported in DEA 1 negative female dogs (previously sensitized to DEA 1 positive cells) mated to DEA 1.1 positive male dogs.

DEA group"old" namePopulation
Natural antibodyTransfusion significance
1.1A140-60%NoAcute hemolytic reaction
1.2A210-20%NoAcute hemolytic reaction
3B5-20%YesDelayed hemolysis
5D10-25%YesDelayed hemolysis
7Tr10-45%YesDelayed hemolysis
* Incidence is breed-dependent, e.g., most Greyhounds are negative for DEA 1.1 (explaining their choice as blood donors) but are positive for DEA 3, whilst large numbers of Labrador retrievers are DEA 1.1 positive.