Who, What, Why: How do dogs donate blood?

National Blood Week has been promoting human donation. But there's a very different blood drive on as well, writes Simon Fry.

As dogs have surgery and other complicated forms of medical treatment, they therefore need blood transfusions. And if dogs have transfusions, other dogs need to donate.

Pet Blood Bank UK is a national canine blood bank service. The first and only UK charity of its kind, it has been operating for eight years and has over 6,000 dogs on its books. On average it stages three blood donation sessions at veterinary surgeries weekly. Up to 22 dogs donate at each session.

To do so they need to meet certain criteria, established in a screening process. Dogs must be in good health and have normal temperature, heart rate and respiration. Dogs are weighed to check they are at least 25kg while owners must confirm the dog has not been abroad, among other requirements.

The practice is booming. In the charity's first year, fewer than 200 donors gave just under 500 units of blood in less than 100 donation sessions - a unit being about 450ml. Now almost 5,000 units are sent to UK vets annually.

As with humans, a small blood sample is taken to ensure the dog can donate. This can be drawn from the dog's cephalic vein in its leg or from the jugular vein from which the donation will be taken. Clipping of the fur prior to needle insertion is standard procedure, but if a vein can be located without clipping the donation can still proceed.

The sample is checked for total solids and red blood cells. Once the dog is cleared to donate, it and its owners go into the surgery's donation room where the dog is lifted onto the operating table and laid on its preferred side. When comfortable and calm, the vet or phlebotomist inserts a needle into the jugular vein and around 450ml of blood is collected over five to 10 minutes, the dog receiving assurance and praise throughout.

"It is not a painful procedure which is confirmed by lots of our repeat donors - many of whom have donated for a few years - bounding through the session doors to see us with their tails wagging," says Pet Blood Bank veterinary supervisor Jenny Walton. She adds that if at any time a dog shows signs of stress the donation stops.

At the end of donation, the dog is given a toy, water and a snack and time to relax, as well as a red bandana to show that it has given blood.

The sealed bag of blood is taken to the charity's centre in Loughborough, Leicestershire, for processing, which involves spinning the bag to separate its plasma and red blood cells. Both are then stored until needed by a vet - the plasma is frozen for up to five years and the red blood cells are refrigerated for up to six weeks.

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