"We just don't have enough blood": Japanese clinics struggle to save dogs for lack of donors, and scientists are trying to grow red blood cells from stem cells

What happened

On 3 November 2026 the Japanese newspaper Mainichi published a Kyodo news agency report on the shortage of blood for dogs. Unlike people, dogs in Japan have no national supply system. Each vet clinic has to find its own blood for animals with severe blood loss after accidents or during operations.

Takashi Mori, director of Daktari Animal Hospital in Kyoto, says his clinic runs a blood bank and keeps a list of donor dogs who can be called in quickly, but there are just three dogs on the list. In his words, there simply isn't enough blood.

Why there's a shortage of donors

Vets often used to keep their own donor dogs, but this is getting harder for animal welfare reasons. The amount of blood a dog can give is limited by its weight, and enough time must pass between donations. When stocks run out, clinic staff sometimes bring in their own dogs to give blood. Few owners agree to have their dog sedated for blood collection.

A hard choice during surgery

The shortage forces difficult decisions. If a tumour ruptures during surgery, the blood is sometimes suctioned and returned to the dog's body. With a malignant tumour this can spread cancer cells, but Mori says it's better than a dog dying on the table for lack of blood. With dogs whose illnesses need regular transfusions, vets sometimes have to say it will be hard to keep them alive.

Why clinics can't simply share

Under Japan's pharmaceutical rules, dog blood counts as a veterinary medicine. Restrictions on transfer and sale stop neighbouring clinics sharing stocks. But Mori believes that relaxing the rules wouldn't solve the problem on its own: donors would still be few, and a large commercial blood bank is unlikely to pay its way at such volumes.

What scientists are doing

A team led by Professor Shingo Hatoya of Osaka Metropolitan University is studying whether dog red blood cells can be produced from induced pluripotent stem cells. Such cells can turn into different cells of the body. In a study announced in July, the scientists added proteins to them and grew them in the laboratory for almost a month.

What the result was

Some of the cells came to resemble red blood cells and contained haemoglobin, the key component of blood. But only about 3% of the starting cells completed the process, so the technology isn't ready for transfusions yet. Hatoya hopes dogs will one day be able to receive blood without depending on donors. But this work is still far from the clinic, and years of research are needed.

When a dog needs a transfusion

Blood is needed after accidents, for heavy bleeding during surgery, ruptured tumours (especially of the spleen), rat poison, severe anaemia and clotting disorders. Sometimes the dog needs not whole blood but just plasma or red blood cells. For many of these dogs a transfusion is a matter of life and death, and without one a vet may not dare to operate.

Blood groups in dogs

Dogs have several blood group systems, and the most important is DEA 1. A dog usually tolerates a first transfusion better than a person, but with repeat transfusions the risk of a reaction rises. So vets do a compatibility test before a transfusion. Dog blood can't be used for a cat: cats have their own blood groups, and a mistake can be fatal.

Which dogs can donate

Requirements vary by country and clinic, but a donor is usually a healthy dog aged about one to eight, weighing at least 25 kilograms, calm, vaccinated and protected against parasites, not on medication and not pregnant. Before donating, the dog is examined and has blood tests. Dogs most often give blood without anaesthesia if they're patient and used to people.

Does it hurt the dog?

The procedure is similar to a person giving blood: blood is taken from a vein in the neck, usually in 10–15 minutes. In some countries calm dogs aren't given a sedative, while in others, such as Japan, sedation is common. Afterwards the dog gets water, food and a treat, and goes home the same day. Don't overdo things with your dog that day, and keep an eye on how it's feeling. A good clinic won't hold a dog by force if it's anxious.

What's in it for the owner

In many countries donation isn't paid for, but the dog gets a free check-up and tests, and sometimes food or discounts. The main benefit is knowing your pet can save another. If your dog is suitable, ask your nearest clinic or university animal hospital whether they have a donor programme and what the rules are.

How things stand in Europe

The situation is better in Europe, but it varies. In the UK, Pet Blood Bank has long been collecting blood around the country, and elsewhere there are university and private banks. An animal blood bank opened in Strasbourg in 2025, and donations are growing, according to French media. In Heverlee, Belgium, a vet is organising a blood donation day this week.

What about cats?

Donation is harder for cats, as they tolerate the procedure calmly less often, usually need light sedation, and give very little blood. Compatibility between groups A, B and AB is stricter in cats, and even a first transfusion without testing can be fatal. So donor programmes for cats are rarer still, and many clinics keep regular donor cats among those belonging to staff.

Other research on blood

Scientists and companies are also working on blood storage and better tests. In the USA, for example, Washington State University has reported research that could help dogs with severe bleeding. New clotting tests are also appearing. Together, this work could make transfusions safer, but it won't replace healthy donors in the coming years.

What you can do in advance

1. Find out where there's an out-of-hours clinic with a blood supply.
2. Ask your vet about your dog's blood group, especially if it often has surgery.
3. Talk about donation if your dog is large and calm.
4. Keep medical records handy: this speeds up decisions in an emergency.
5. Keep poisons and rat bait out of dogs' reach.

How to prevent blood loss

Many transfusions are needed because of accidents and poisoning. Keep your dog on a lead near roads, don't leave rat poison within reach, and take older dogs to the vet regularly: a spleen tumour is often found on ultrasound before it ruptures. Pay particular attention to breeds prone to these tumours, such as German shepherds and golden retrievers.

Dogs that need regular transfusions

With some diseases, such as immune-mediated haemolytic anaemia, a dog may need several transfusions before treatment takes effect. For the owner this means a lot of stress and expense. Ask your vet about the treatment plan and the chances, find out about the clinic's stocks, and don't hesitate to ask for a second opinion if this helps you decide.

How European blood banks work

In the UK the charity Pet Blood Bank runs donor sessions around the country and supplies clinics with blood. In other countries, university and private clinics more often hold stocks. Blood is separated into components, so one donation can help several patients. This only partly solves the problem facing Japanese clinics, as regular donors and rules allowing stocks to be shared are still needed.

Why a national system matters

If Japan had a single network, blood could be moved quickly to where it's needed. At the moment even neighbouring clinics are limited by the rules. Human medicine shows that central storage and data sharing reduce waste and shortages. For animals, such systems are only starting to develop and depend on the goodwill of owners and vets.

What this means for Europe

Although Europe has blood banks, demand is growing along with the number of complex operations and older pets. Japan's experience shows how quickly a lack of donors becomes a matter of survival. Europeans should support donor programmes and think about common rules for passing blood between clinics, especially in rural areas.

When to see a vet

Take your dog to a clinic immediately if there's heavy bleeding, after an accident, or if you see pale gums, weakness, collapse, a swollen belly, or if your dog may have eaten rat poison. Phone before you set off, so the clinic can prepare and check its blood supply. On the way, keep your dog warm and as still as possible.