Chronic myelogenous leukaemia with meningeal infiltration in a dog

Abstract

Chronic myelogenous leukaemia was diagnosed in a 10-year-old mixed-breed dog with marked leucocytosis and severe left shift (WBC = 160000/μl; 2% promyelocytes, 2% myelocytes, 17% metamyelocytes, 36% bands, 42% segmented neutrophils, 1% lymphocytes), non-regenerative anaemia (PCV = 18%), and splenomegaly. Treatment including splenectomy, chemotherapy, antibiotic therapy, and blood transfusions controlled the leucocytosis for 21 months, but did not resolve the anaemia nor prevent infiltration of the central nervous system. The bone marrow was hypercellular and contained 26% blasts, 68% maturing granulocytes, 6% erythroid precursors, and no megakaryocytes. Histological examination revealed neoplastic infiltration in the bone marrow, kidney, liver, and brain, and a purulent bronchopneumonia.