If your cat were to have an accident today, would you know their blood group? Just like in humans, the blood of our cats is not universal. The feline blood group system (the AB system) classifies cats into three main types: A, B and, more rarely, AB.
Although group A is the most common, there is significant clinical concern regarding type B blood in cats.
The deadly danger of an incorrect transfusion
In an emergency situation, a blood group transfusion in cats must be carried out with extreme caution. Unlike dogs, cats possess very powerful natural antibodies against the blood group they do not have.
If a cat with type B blood receives a transfusion of type A blood, its immune system will attack and destroy the donated red blood cells almost immediately. This adverse reaction is severe and often fatal. Clinical consequences include shock, a drastic drop in blood pressure and organ failure. Of course, the reverse scenario (donating type B blood to a type A cat) is also dangerous, but the most severe and fulminant reaction always occurs in recipients with the "B factor".
Neonatal isoerythrolysis: The silent risk during birth
The danger of blood group B is not limited to veterinary emergencies; it is a critical risk in breeding. When a female with type B blood mates with a male with type A (or AB) blood, the kittens can inherit group A.
During the first hours of life, whilst suckling their mother's colostrum, the kittens ingest the mother's powerful anti-A antibodies. Once in the little ones' bloodstream, these antibodies attack their own red blood cells, causing a lethal haemolytic anaemia known as neonatal isoerythrolysis. Without warning, an entire litter can fade away in a matter of days.
Are there cat breeds with a higher risk of type B blood?
Although type B is less frequent globally, its prevalence is higher in certain breeds. There are cat breeds with high percentages of type B blood, which obliges their breeders to be on high alert. Some of the breeds with the greatest predisposition to possessing this blood group include:
- British Shorthair
- Devon Rex and Cornish Rex
- Sphynx
- Persian and Exotic Shorthair
- Scottish Fold
Note: Mixed-breed cats can also carry blood group B, so it should never be assumed that an ordinary European or mixed-breed cat has type A blood.
Genetics: The fastest and safest way to get to know your cat
Before planning a litter or facing an emergency in the dark, science can make the difference. Genetics is a fast and painless tool that can provide useful data on your feline's blood group predisposition and help detect dangerous mutations.
To evaluate the blood group system and prevent incompatibilities, we study the different mutations of the CMAH gene:
- Blood Group AB (variant 1)
- Blood Group AB (variant 2)
- Blood Group AB (variant 3)
- Blood Group AB (variant 4)
Beware of clotting disorders
In addition to blood groups, feline blood can hide other serious genetic problems that compromise health during surgeries or accidents. One of the best-known bleeding disorders is Haemophilia. For this reason, the Koko Genetics DNA test for cats also evaluates your genetics against critical hereditary diseases such as Haemophilia B (variant 1) and Haemophilia B (variant 2).
