Last week, I had an appointment to give blood. While I was having breakfast I got a call from work: would Ollie be able to give blood today? So my dog and I both gave blood that morning, and while he didn’t have to fill out the same in depth questionnaire I did, and he didn’t have any tests run on his blood beyond a simple CBC, the donation process was very similar. I don’t know what happened to my blood, but I know Ollie’s was used right away to try to save another dog’s life.
I’ve mentioned before that Ollie is a blood donor. He saved one of my clients my first fall out here, and that dog went on to live for several months longer than predicted by the tumor we removed! Not all of the recipients of his blood have been so lucky – unfortunately if we’re collecting Ollie’s blood it is typically because another dog is in immediate and desperate need. Occasionally we will collect pre-emptively if we expect high blood loss in surgery (like removing a splenic tumor), but we can’t always predict high blood loss (like the first dog in Newfoundland Ollie gave blood to – a dog hit by a car. . . )
When I introduced you to Ollie I mentioned that he came into my life because he was a blood donor at my school. Technically he is retired – but when we have patients in need of blood, we unfortunately do not have a lot of options here in St John’s. It is possible to order in blood products, but they don’t keep forever and it’s not always practical to be paying for them ‘just in case’ so we don’t normally have them on hand. In an emergency we rely on staff owned animals, and being an experienced donor, Ollie is often called upon: he’s been thoroughly tested, is a known universal donor and reliably has a high red cell count. Also, he’s one of the best behaved dogs in the world and is super cooperative for collection. He lays nice and still on the table while a large needle is stuck into his jugular and a pint of blood is collected, just so long as he gets lots of cuddles and cookies before and after – and the staff is always quick with the cuddles and cookies when Ollie comes to visit!
Blood types in dogs are described by DEA (dog erythrocyte antigen), and the most significant for blood transfusion purposes are DEA 1 and it’s subsets. . . and dog may be positive or negative for these. Dogs that are DEA 1 negative are considered universal donors – this is what Ollie is! Breeds that typically are DEA 1 negative include Greyhounds, Boxers, Newfoundlanders, Great Danes, Mastiffs, and Dobermans. Breeds that tend to be DEA 1 positive include Golden Retrievers, Rottweilers, and Labrador Retreivers. Of course, there are always exceptions, and any potential blood donor would have his (or her!) blood typed. There’s several different DEA that can be checked, but 1.1/1.2 and 7 are the most important (so I’m told. . . )
A donor should be over 25kg (lean weight – aka in good body condition, not overweight!) under 8 years of age, and have a good temperament for collection. They should be spayed or neutered, and if female they shouldn’t have had any puppies. At time of donation they should be in good health with no risk for bacteria in the blood stream (in other words, those with very bad teeth need not apply until those pearly whites are indeed white again). A potential donor should never have previously received blood product, and should not be on any medications except parasite control. Potential donors at OVC are screened for a number of blood borne infectious agents, which may not be affecting the donor but would be harmful to the immune compromised recipient.
Pretty much the same system is used to collect the blood as is used in people– which is why the size requirement: at least 405 mL of blood needs to be collected to be useable (because of the anticoagulant present in the collection bag, a certain ratio needs to be maintained). A typical collection is about 450 mL. The amount of blood taken from a donor should not exceed 21 ml/kg every 21 days. . . I don’t let Ollie donate any more often than every 2 months.
In an ideal world, donor and recipient would always be cross matched. This is obviously not always possible in the veterinary world– though there are basic techniques that can be done in general practice to check for agglutination (sticking together of red blood cells), typically we have to send away for full assessment (to check if the red blood cells get destroyed when the two bloods meet), and we don’t always have time for that. If it’s the recipient’s first time receiving blood and the donor is known to be a ‘universal donor’, then you’re typically pretty safe to go. However, the transfusion is always started very slow and the recipient is monitored very carefully. High risk recipients – those who some kind of cross match should be done – include dogs who have had a transfusion in the past or have an unknown transfusion history.
So there’s Canine Tranfusion Medicine in a super basic nutshell. . . if you’re interested in learning more, here are a few websites:
Blood donor program at the Ontario Veterinary Colleg– the program Ollie was originally a part of.
Lifestream – Animal Blood Bank– where we can order products from if we want them on hand
Blood Donor Program at University of Pennsylvania – another program at a vet school, with a nice and informative website