Granulocyte hyposegmentation (HG) in Australian Shepherds describes a specific change in the blood of affected dogs. HG is inherited in an autosomal recessive mode of inheritance and, as far as is known at present, is not associated with other problems. The phenotype should therefore be distinguished from human Pelger-Huët anomaly, which causes similar changes in the blood work, but can also be associated with much more severe changes. In collaboration with the University of Zurich, we have succeeded in identifying the causal genetic defect for HG, and to develop a genetic test.
