Pelger-Huët anomaly (PHA) is a rare, inherited blood condition in which the nuclei of several types of white blood cells (neutrophils and eosinophils) have unusual shape (bilobed or dumbbell-shaped) and structure (coarse and lumpy). It may also be called Pelger’s nuclear anomaly, or Pelger-Huët nuclear anomaly.
When only one defective copy of the gene is inherited (heterozygous), PHA can exist by itself with no detrimental effect to the dog. However, if a defective gene is inherited from each parent (homozygous), the disorder in dogs is typically lethal in utero or shortly after birth, leading to neonatal deaths and lower litter sizes surviving to weaning than in normal dogs