Polycythemia vera-related MDS in a dog

Abstract

A young male Doberman dog was presented with a short period history of anorexia and weakness. The main clinical signs were red mucous membranes, conjunctival hyperemia, dilated retinal vessels, seizures, and head extension. Laboratory findings revealed a moderate thrombocytopenia and a significant erythrocytosis, together with reticulocytosis and the presence of erythroid precursors in the blood film. Serum erythropoietin concentration was low–normal. The erythroid elements occupied the bone marrow and consisted of highly dysplastic forms. Rubriblasts constituted 8% of all nucleated cells of the bone marrow. Though megakaryocytic hypoplasia was remarkable, the megakaryocytic lineage was the other affected cellular line, with dysplastic features such as micromegakaryocytes. The granulocytic elements showed minimal dysplasia. A final diagnosis of polycythemia vera-related myelodysplastic syndrome was made. It is a highly aggressive condition, leading to death shortly after admission. Future studies on chromosome changes and specific mutations associated with the development of acute leukemias or myelodysplastic syndromes following chronic myeloproliferative diseases in animals are critical.