Xenotransfusions – How Cats Can Receive Canine Blood in Emergencies
Time for a fascinating cat fact; did you know that in life threatening situations it is possible to give a cat a blood transfusion using canine blood?
In fact a xenotransfusion (the transfusion of blood from another species) of canine blood to cats used to be a relatively common procedure in the U.K and is still performed in countries where the availability of Oxyglobin, (a haemoglobin-based oxygen carrier solution) is scarce.
When treating an anaemic cat where compatible feline blood cannot be obtained, a vet can perform a transfusion with canine blood.
The interesting issue here is that felines do not have any naturally occurring antibodies against canine red blood cell antigens.
There have been various studies carried out regarding the practice and no severe acute adverse reactions have ever been reported. In fact, anaemic cats receiving canine blood are said to improve clinically within hours.
However, there is a somewhat serious caveat: after receiving the transfusion, the cat will very quickly produce their own antibodies against the canine red blood cells. This will occur within 4-7 days of the transfusion, leading to the destruction of the transfused canine red cells in a delayed haemolytic reaction.
The average lifespan of the transfused canine red cells is less than 4 days. Because of the rapidly produced antibodies, repeated transfusion with canine blood later than 4-6 days after the first transfusion causes anaphylaxis, which is in most cases fatal.
So it is very much a one time only procedure.
The subject of xenotransfusions is an interesting one. Early pioneers such as Jean-Baptiste Denis, attempted early blood transfusions across species with humans back in the 1600’s.
However the practice was completely abandoned following the discovery of blood groups by Karl Landsteiner in 1900.
From 2000, due to progress in xenotransplantation and the need of blood supply, it is once again being considered for humans. Pigs are so far the best potential donors.
However, the main obstacle to porcine red blood cell transfusion remains. Namely the cellular response involving macrophages or natural killer cells, i.e how to stop our bodies from automatically producing antibodies against the transfusion.