Life blood – can you help?

Have you ever wondered what happens when an animal needs a blood transfusion?

When a dog or cat needs blood, we can use blood from another dog or cat. But when we need a bag of blood, we can't call anything like the Red Cross Blood Bank, we need to call up a donor owner and ask for a very special favour.

When might pets need blood?

The main reasons why your dog or cat could need a blood transfusion include:

• trauma (especially being hit by a car)
• rat bait toxicity (rat bait stops blood from clotting and leads to bleeding)
• immune mediated conditions (where immune cells mistake red cells as foreign and remove them)
• bleeding tumours (especially splenic tumours that can spontaneously rupture)

Hopefully, your pet will never experience any of these things. But if things do go wrong, it's reassuring to know that life-saving transfusions are available.

Do pets have blood groups?

Yes, they do.

Cats can be type A, type B or (rarely) type AB. There are no 'universal donors' when it comes to cats – type A cats can only receive type A blood and type B cats can only get type B blood. Most cats are type A. Type B cats are much less common, but some breeds are more likely to be type B such as British Shorthair. The key thing here is that we have to perform blood typing on cats before they donate or receive blood.

Dogs have rather complex blood groups. Fortunately, there is an equivalent of a 'universal donor' for dogs. This is type DEA 1.1 negative – and Greyhounds generally have this blood type.

How do pets donate blood?

Cats and dogs donate blood in much the same way as people do. A needle is placed into a vein and blood flows out through some tubing into either a bag (dogs) or a syringe (cats) that contains an anticoagulant. The main differences between people and pet donations are:

• pets donate blood under either sedation (dogs) or general anaesthetic (cats)
• blood is taken from the jugular vein in the neck rather than from an arm vein
• pets go on a drip during and after the procedure so the blood that is taken is replaced by IV fluids

And pets are rewarded with a big bag of food rather than a sandwich and a cup of tea.

The whole process takes about an hour. The actual blood donation only takes about 10 minutes – the extra time is in the preparation and recovery of the sedation/anaesthetic. Within a couple of hours, the donor is back to pretty much normal.

Pets can safely donate every 3 months. However, it would be unusual for us to call up a donor more than once a year.

Dog blood can be stored for around a month but cat blood can't be stored. When we need to give a cat a transfusion, we need to have a donor nearby. 

Can any pet donate blood?

No. For the safety and benefit of both the donor and the recipient, donors need to meet certain criteria.

For dogs to be suitable donors, they need to be:

• 25 kg or more
• healthy
• between 2 and 7 years of age
• okay with being at the vet
• (heartworm negative or on prophylaxis)

They also can't have ever received a blood transfusion or any serum/plasma product (eg snake antivenom) or have been pregnant. Basically, their blood can't have ever mixed with the blood of another dog, which could have caused antibodies to form.

Greyhounds make ideal donors because they have higher red cell counts than other breeds (ie their blood is more concentrated), they are generally the 'right' blood type and they're almost always sweet natured dogs that are easy to work with (and so need minimal sedation).

For cats to be suitable donors, they need to be:

• 5 kg or more
• healthy
• between 2 and 7 years of age
• FIV negative (we test potential donors)
• blood typed (we do this for potential donors)
• easy to handle

Cat donors also can't have ever received a blood transfusion or any serum/plasma products (eg snake antivenom) or have been pregnant.

As type B cats are uncommon, we're always on the look out. Type B cats are a special form of gold!

Could my pet be a donor?

We love you for even considering it! If you're interested in going onto a donor register, please fill out the form below. Filling it out doesn't obligate you in any way, it just means we'll give you a call to discuss things some more and go from there.