Blood transfusions are of importance not only in human medicine. Also animals do need blood donations. The University of Veterinary Medicine Vienna has operated a blood bank for dogs for more than a decade, but they aren't the only animals that can benefit from blood transfusions. Horses sometimes need blood donations during operations that involve high blood loss.

Blood can't be created through artificial means, but it can be transferred within a species. As with people, animals also have different blood types. Animal blood, as well as human blood, is divided into various groups based on different surface proteins found on the red blood cells. Eight different blood types have been described horses. The transfusion of an unsuitable blood type can have fatal consequences for animals; for instance, when a cat with blood type B receives type A blood, the results generally aren't favorable. For horses and ruminants, the first time transfusion of "wrong" donor blood is generally safe. With each additional transfusion, however, blood types become crucial, as the animals have produced antibodies against the foreign blood that can cause serious immune reactions.

There are various reasons for blood donations in equine medicine. These include clotting disorders of the blood, anaemia, poisonings, or serious infectious diseases, as well as perioperative blood loss. For the latter, blood is stored and kept ready for use during surgery in areas with strong blood supply, such as the nose and jaw. A blood transfusion can help sustain adequate circulation of the animal during the operation and speeds recovery.

René van den Hoven, DVM, PhD, D