Background
For cats different kinds of blood types exist, of which the AB-system is the most important one. In this system, cats can have an A, B or AB blood type.
The presence of naturally occurring high amounts of anti-A antibodies in type B cats, leads to the bursting of type A red blood cells when they get into contact with type B blood. This is for example the case in neonatal isoerythrolysis (NI). NI can occur when a queen with blood type B is bred to a tom with blood type A, giving birth to kittens with blood type A. When drinking colostrum during the first days of life, the kittens absorb the anti-type A antibodies produced by the type B queen. This will lead to the bursting of the kitten’s type A red blood cells, causing anaemia, which can be lethal. It is therefore important for breeders to test the blood type of breeding queens, to identify the risk of NI and minimizing the chances of neonatal mortality.
The genetic tests K793 and K300
Genetic test K793, available for all breeds *, identifies two types of recessive b alleles which are associated with blood type B. By analysing these two mutations together, it is possible to predict the type B blood type in cats. Since additional mutations yet have to be identified, there is a possibility that the genetic results from this test do not match the conventional blood typing results (serology).
Genetic test K300, available for Ragdolls, identifies one variant of the AB allele and is associated with type AB blood in Ragdoll cats. Since blood type AB cats from other breeds do not have the Ragdoll type AB variant which is analysed with the K300 genetic test, at least one other variant must be present that also results in type AB blood in other cat breeds. This variant has yet to be identified.
Serologic test K712
Another method to identify cat blood types, is serology. This method does not give information about the genetic background in a direct way and is therefore not suitable to use as a solely method when making breeding choices. When genetic tests (K300 and/or K793) do give an inconclusive result (type A or AB), the serologic test can be used to make a distinction between type A or type AB blood.
Serologic blood typing is mainly used for blood transfusions and can only be performed on whole blood (EDTA or Heparin).
Interpretation of results
Cats with two copies of any of the two b alleles have type B blood. Cats with one copy of any of the two b alleles and thus carrier of b have either type A or AB blood, depending on which second allele is present.
Ragdolls with two copies of the AB allele have type AB blood. Ragdolls with one copy of the AB allele and thus carrier of AB have either type A type AB blood, depending on which second allele is present.
Please note that it is not possible to distinguish between blood type A or AB with our genetic tests when only test K300 (Ragdoll only) or test K793 is performed. To make a distinction between blood type A or AB, serologic test K712 can be used. For Ragdolls it is advised to perform both K300 and K793 to receive the most accurate result.
Interpretation blood type (all breeds *) – K793
| Genetic result | Genotype | Interpretation |
|---|---|---|
| No b allele | N/N | Cat has blood type A or AB ** |
| One copy of one of the two b alleles | N/b | Cat has blood type A or AB ** |
| Two copies of any of the two b alleles | b/b | Cat has blood type B |
| Inconclusive | – | Blood type cannot be determined, cat has blood type A, B or AB. Serologic test K712 can give additional information. |
Interpretation blood type (Ragdoll) – K300
| Genetic result | Genotype | Interpretation |
|---|---|---|
| No AB alleles | N/N | Cat has blood type A or B *** |
| One copy of the AB allele | N/AB | Cat has blood type A or AB ** |
| Two copies of the AB allele | AB/AB | Cat has blood type AB |
Interpretation blood type (Ragdoll) – K300 and K793 combined
| Result K300 | Result K793 | Interpretation |
|---|---|---|
| N/N | N/N | Cat has blood type A |
| N/AB | N/N | Cat has blood type A |
| AB/AB | N/N | Cat has blood type AB |
| N/N | N/b | Cat has blood type A |
| N/AB | N/b | Cat has blood type AB |
| N/N | b/b | Cat has blood type B |
* Some breeds like Siamese, Burmese and Oriental Shorthair do not have the b allele
** Please note that it is not possible to distinguish between type A or AB blood with our genetic tests. To make a distinction between blood type A or AB, serologic test K712 can be used to give additional information.
*** Please note that is not possible to distinguish between type A or B blood with only genetic test K300 in Ragdolls, genetic test K793 can be used to give additional information.
