Inherited macrothrombocytopenia in a Cavalier King Charles Spaniel


The dog had a platelet count of 71 thou/uL (moderate decrease), with an MPV of 22.6 fL (increased). The platelet crit (PCT) was 0.16, which is within reference intervals, indicating a normal platelet mass (the PCT is equal to the platelet count x the mean platelet volume). The dog was not symptomatic (which is expected in these breeds with an inherited defect in beta-tubulin).