We present a case of acute erythroid leukaemia with a myeloblastic component (AML-M6) in a dog. This is the first case reported since the French-American-British classification was adopted. Cytology and electron microscopy of a bone marrow aspirate were used for the diagnosis. Flow cytometry, which is
commonly used for the immunophenotyping of canine acute leukaemias, was not suitable for the analysis of this sample, because early erythroid precursors were destroyed by the red blood cell lysis procedure.