MDS Myelodysplastic Syndromes

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Myelodysplastic Syndromes are diverse, complicated & very rare in dogs . Any type of MDS is an acquired hematopoietic stem cell disorder in the bone marrow of dogs which prevents the proper production of healthy myeloid line of blood cells (RBCs, WBCs, platelets  but NOT lymphocytes).  MDS is sometimes referred to as pre-neoplastic syndrome or pre-leukemia as it usually develops into acute myelogonous leukemia.

The various types of MDS cause blood abnormalities including anemia (which can be non-regenerative or regenerative), neutropenia, thrombocytopenia, macrocytic (abnormally large) erythrocytes,  the release of immature erythrocytes & sometimes reticulocytosis.

A diagnosis of Myelodysplasia is made when 30% or less of cells in the bone marrow are myeloblasts. Diagnosing specific types of MDS is a complicated subject & there are many, many different terms used to describe each type. Please note: it is advisable to test for Ehrlichia infection before making a definite diagnosis as the symptoms are often quite similar to MDS.

MDS can be primary or secondary to another disease such as leukemia, AIHA, IMT, multiple myeloma, lymphoma, polycythemia vera, thrombopathia, pyometra.

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