1014 Swiss housecats have been blood typed. 99.6% had blood group A an
d 0.4% had blood group B, with no type AB cats detected. The transfusi
on 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 hav
e 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 conc
luded that there is a minimal risk for incompatibility reactions due t
o blood transfusions. The same could be said of neonatal isoerythrolys
is which is unlikely to occur with the random mating of housecats.