Blood Groups - Cat

Cats and dogs have very different blood grouping systems. Cats have an A-B blood group system and inherit blood types as a simple dominant trait where by A is dominant over B.

Cat blood can be classed as Group A, B or AB. Group A which can be either A/A or A/B is the most common blood type of domestic short and long haired cats in the UK.

Group B which is always B/B is very common in Devon Rex, Persians, British Shorthair, Somali, Himalayan and Birman breeds.

Rarely cats can also be group AB.

Both the blood donor and recipient should always be blood typed prior to transfusion. This is especially important in cats due to the occurence of alloantibodies.

Group A cats have low titres of anti-B antibodies.

Group B have high titres of anti-A antibodies and giving Group B cats type A blood can result in a potentially fatal transfusion reaction.

Blood group incompatilibility in Cats

Donor Group	Recipient group	Transfusion reaction
A	A	None
B	B	None
B	A	Slight
A	B	Potentially fatal

Time is needed to determine full compatibility tests which is not always possible in the emergency situation.