Background

Hereditary pyruvate kinase (PK) deficiency and AB blood type incompatibility can result in severe haemolysis.

Aims

To determine the frequency of the mutant PK allele and AB blood types in Australian Abyssinian and Somali cats.

Methods

A complete blood count, reticulocyte count, DNA PK mutation testing and blood typing were performed in all cats recruited from the Australasian breed association.

Results

Sixty cats (36 Abyssinians, 24 Somalis) were tested comprising 31 females (29 entire, 2 neutered) and 29 males (21 entire, 8 neutered). For the mutant PK allele, 3 female Somalis (2 entire multiparous and 1 neutered, 2-3 years old) were homozygous (5%), 17 cats were heterozygous (28.3%) and 40 cats tested negative (66.7%). Of affected cats, 2 had regenerative anaemias and all had reticulocytosis (range 64-390 x 10⁹/L; p< 0.001 compared to normal or carrier cats) and were alive 1.5 years after testing. The only consistent historical sign was lethargy. Pedigree analysis revealed common ancestry. The mutant allele frequency was 0.29 in the Somali group, 0.13 in the Abyssinian group and 0.19 overall. All cats had blood type A.

Conclusion

The mutant PK allele frequency is high and DNA screening of these breeds is indicated worldwide especially when there is reticulocytosis, even in the absence of anaemia or clinical signs. The risk of haemolytic anaemia from AB blood incompatibility in this population is low.