When I first heard a rumor about a cat in New Zealand whose life was saved with a transfusion of dog blood, my initial reaction was “no way.” Transfusions are tricky business, particularly in cats. Get the blood typing wrong and things can quickly go from bad to worse. But when I found and read the article about the procedure in the New Zealand Herald, I realized that I was mistaken.

The story goes something like this:

Owner finds cat (Rory) limp and howling and rushes him to the vet.

Vet determines cat has eaten rat poison and will soon die without a blood transfusion, but it is Friday night and the laboratory that can determine the cat’s blood type is closed.

Vet gets advice from animal blood bank about using dog blood essentially saying that the cat will certainly die without it and stands a decent chance of surviving with it.

The cat’s veterinarian (Kate Heller) said, "People are going to think that it sounds pretty dodgy — and it is — but hey, we've been successful and it's saved its life.'' Prior to the transfusion Rory was "really flat and gasping and howling,'' and one hour later he was sitting up, purring, and "tucked into a bowl of biscuits.''

Too cool, eh? I’m not sure if I was asleep during part of my transfusion lectures in veterinary school or if this tidbit was never brought up, but honestly it wouldn’t have even dawned on me to consider using dog blood to transfuse a cat. I did a little more research into the process of xenotransfusion (the transfusion of blood of one species to another) and I found this review article:

Published evidence in a limited number of cases (62 cats) indicates that cats do not appear to have naturally-occurring antibodies against canine red blood cell antigens: compatibility tests prior to the first transfusion did not demonstrate any evidence of agglutination or haemolysis of canine red cells in feline serum or plasma. No severe acute adverse reactions have been reported in cats receiving a single transfusion with canine whole blood. Anaemic cats receiving canine blood are reported to improve clinically within hours. However, antibodies against canine red blood cells are produced rapidly and can be detected 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. Any repeated transfusion with canine blood later than 4-6 days after the first transfusion causes anaphylaxis, which is frequently fatal.

What this means is that xenotransfusion is at best a stop gap measure. It may be successful if veterinarians can get the primary problem under control within a few days and/or make arrangements to obtain properly cross-matched blood within the same time frame, but under no circumstances can xenotransfusions be repeated.

I hope you never need to bring this possibility to your veterinarian’s attention, but it’s good information to tuck away, nonetheless.

Dr. Jennifer Coates

References

Cat saved by dog's blood. Brendan Manning. The New Zealand Herald. 7:28 PM Tuesday Aug 20, 2013.

Xenotransfusion with canine blood in the feline species: review of the literature. Bovens C, Gruffydd-Jones T. J Feline Med Surg. 2013 Feb;15(2):62-7.

Image: Ermolaev Alexander / Shutterstock