[The blood group distribution in domestic cats in Switzerland]

1014 Swiss housecats have been blood typed. 99.6% had blood group A and 0.4% had blood group B, with no type AB cats detected. The transfusion of blood, or the transfer of antibodies to newborn kittens through colostrum, can cause clinical signs of incompatibility. Because almost all B-cats have high naturally occurring antibody titers against the other blood group, it is the B-cat which is most likely at risk to have incompatibility reactions after a blood transfusion and it is the B-queen which has high antibody titers in the colostrum. In the contrary only about one third of the A-cats have antibodies and usually in low titers. The present investigation demonstrates that the incidence of blood type B in Swiss housecats is very low. Therefore, it can be concluded that there is a minimal risk for incompatibility reactions due to blood transfusions. The same could be said of neonatal isoerythrolysis which is unlikely to occur with the random mating of housecats.