How Blood Transfusions Saved Two Very Poorly Cats.
Blood transfusions have long been an important part of veterinary medicine, particularly for dogs. However, transfusing cats presents some unique challenges. Careful blood typing and close monitoring are essential to help make these life-saving procedures as safe as possible.
Recently, we treated two very poorly cats, Dobby and Violet, who both arrived suffering from severe anaemia. Their stories highlight just how critical prompt diagnosis and treatment can be — and how remarkable the results of a blood transfusion can be.
Why is blood typing so important in cats?
Unlike dogs, cats naturally develop antibodies against certain blood types during the first few months of life. This means that a cat can experience a serious transfusion reaction even if it has never received a blood transfusion before.
Cats have three main blood types: A, B and AB. Type A cats generally have lower levels of antibodies against type B blood, whereas type B cats often have strong antibodies against type A blood. Giving incompatible blood can therefore cause a potentially life-threatening reaction.
For this reason, cats must have their blood type checked before every transfusion, including their first. Blood typing is a vital step in selecting compatible blood and reducing the risk of complications.
Certain infectious diseases can also affect a cat’s red blood cells and complicate the picture, making thorough investigation particularly important.
To learn more about feline blood typing, visit the Pet Blood Bank UK website.
Why might a cat need a blood transfusion?
There are three broad reasons why a cat may become severely anaemic and require a blood transfusion.
1. Blood loss
Significant blood loss can occur following trauma, including road traffic accidents, or as a result of parasites, bleeding disorders or problems with blood clotting.
For example, exposure to certain rodenticides can interfere with normal blood clotting, potentially leading to severe internal bleeding.
Cats that have been injured, have a heavy parasite burden or are experiencing unexplained bleeding may therefore need urgent assessment and, in some cases, a transfusion.
2. Destruction of red blood cells
Sometimes, red blood cells are destroyed faster than the body can replace them. This is known as *haemolytic anaemia*.
In cats, possible causes include infectious diseases such as *Mycoplasma haemofelis*, a blood-borne organism that can cause feline infectious anaemia. Feline leukaemia virus (FeLV) and other underlying diseases may also contribute to anaemia.
Toxic substances can cause serious problems, too. Everyday items that may seem harmless to us, including onions, garlic and paracetamol (acetaminophen), can be highly toxic to cats.
Treatment depends on the underlying cause and may involve supportive care, appropriate medication and, in severe cases, a blood transfusion.
3. Reduced production of red blood cells
Red blood cells are produced in the bone marrow. If the body cannot make enough new cells to replace those that are naturally lost, anaemia can develop.
This is known as *non-regenerative anaemia*. Possible causes include chronic kidney disease, certain cancers, bone marrow disorders and some viral infections, including feline immunodeficiency virus (FIV).
These conditions may be more commonly encountered in older cats, although cats of any age can be affected.
Dobby and Violet: two cats in desperate need of help …
We recently saw two cats whose presentations were particularly concerning.
Dobby, just 15 months old, was brought in after her owner reported that she had fallen. Violet, aged five, was unable to walk properly and kept collapsing.
Both cats were weak, had very pale gums and had sunken-looking eyes — worrying signs that prompted us to investigate urgently.
We took blood samples from both cats to assess a range of health indicators. Of particular concern was a measurement called the packed cell volume (PCV).
PCV tells us what proportion of the blood volume is made up of red blood cells. These cells contain haemoglobin, which carries oxygen around the body. When the PCV falls dramatically, the body struggles to deliver enough oxygen to its tissues.
A typical PCV reference range for cats is approximately 30–45%, although the precise range can vary between laboratories.
– Low PCV: Indicates anaemia and a reduced proportion of red blood cells.
– High PCV: May indicate dehydration or, less commonly, an abnormally increased red blood cell concentration.
Dobby’s PCV fell to an alarming 5%, while Violet’s was just 7%. Both values were dangerously low compared with the expected range.
At these levels, urgent treatment was essential.
A race against time
Although we had not yet established the exact cause of either cat’s anaemia, we suspected that red blood cell destruction was playing a significant role.
We decided that blood transfusions were a critical part of their immediate treatment while further investigations continued.
Both cats were started on medication, including corticosteroids to help suppress an inappropriate immune response that may have been contributing to red blood cell destruction. They were also given doxycycline, an antibiotic used to treat certain infections, including Mycoplasma haemofelis.
Because feline blood compatibility is so important, we typed each cat’s blood before obtaining a suitable blood product.
The transfusions were administered gradually over several hours, with a dedicated veterinary nurse monitoring each cat closely throughout the procedure. Careful observation allowed us to watch for any signs of a transfusion reaction and assess how they were responding to treatment.
Once a blood product has been prepared for use, it must be handled and administered according to strict storage and safety protocols. Any remaining product that cannot safely be retained must be discarded.
The remarkable difference a transfusion can make
The photographs tell the rest of the story.
Dobby’s photographs were taken three weeks after her transfusion, when she returned for repeat blood tests to check whether her red blood cell levels had remained stable. It was encouraging to see her back for that important follow-up assessment.
Violet’s photographs were taken during her transfusion — and they capture a particularly memorable moment.
Halfway through the procedure, Violet began to feel noticeably better. She started rolling around, playing and showing an interest in food again.
Seeing such a change in a cat who had arrived unable to walk properly and repeatedly collapsing was a wonderful reminder of how important timely treatment can be.
A transfusion does not necessarily resolve the underlying cause of anaemia, so continued investigation, treatment and follow-up are essential. However, it can provide vital support while the veterinary team works to address the problem.
A huge thank you to Dobby and Violet’s owners
We are incredibly grateful to both owners for seeking veterinary care and giving their cats the chance to recover.
Dobby and Violet’s cases are a reminder that anaemia can be life-threatening, sometimes developing with surprisingly subtle signs before a cat becomes critically unwell.
If your cat seems unusually weak, has pale gums, collapses or is struggling to walk, seek urgent veterinary advice.
Blood transfusions require careful preparation, compatible blood products and close monitoring, but in the right circumstances, they can make a life-saving difference.
We’re delighted to have been able to help Dobby and Violet — two very special cats whose stories show just how much a timely transfusion can matter.