Do dogs also have a rhesus factor?

Answer

Dear Jean Paul,

The system of blood groups is different in the dog: there are more than 12 types here, the most important are DEA 1.1, DEA 1.2, DEA 3, DEA 5, DEA 7 & Dal.

Dogs usually do not naturally have antibodies against the blood group that they do not have themselves, they must first be sensitized (& create antibodies) to be able to react against a foreign blood group.

This means that in principle a dog, if it has never undergone a blood transfusion before, can undergo a first transfusion relatively safely. In most cases (dogs rarely need a transfusion let alone multiple transfusions) blood can even be given from a non-matching donor and testing is not necessary, with some important exceptions:

• If a dog needs multiple blood transfusions (or has had one before), testing and using a matching donor is necessary.
• Of the blood groups listed, it is known from DEA 1.1 that a reaction to this type is very violent (hemolysis, etc.). DEA 1.1 is also relatively common. That is why DEA 1.1 is tested as standard. DEA 1.1-negative patients will not receive DEA 1.1-positive blood even with their first transfusion, in order to rule out all risks.
• A number of breeds (e.g. greyhounds, dalmatians,…) often have different blood group compositions within the breed than usual in the general dog population. Here, too, some extra attention is required. Dal-negative Dalmatians, for example, respond immediately to a first transfusion of unmatched blood.

Blood transfusions in dogs are possible thanks to the willing cooperation of owners of large dogs (> 25 kg, healthy, properly vaccinated, never had blood before, bitches must not have had a litter either). Either the veterinary clinic sets up its own blood bank, thanks to a pool of donors (each of whom can give blood every three months), other centers and practices have agreements with donors’ owners and can quickly summon them to take blood in an emergency and use immediately.