Acute myelomonocytic leukemia with multifocal manifestation and spinal cord infiltration in a dog

Few cases of myelomonocytic leukemia associated with neurological signs have been described in dogs; none have been related to intraparenchymal spinal cord infiltration by neoplastic cells. This short communication describes a case of acute myelomonocytic leukemia subtype M4 in a dog with spinal cord infiltration. A 3-year-old male Golden Retriever was presented with a history of hyperthermia, lymphadenomegaly, leukocytosis with circulating blast cells, anemia and thrombocytopenia, and acute onset paraplegia. Immunophenotyping of peripheral blood by flow cytometry was consistent with acute myelomonocytic leukemia subtype M4. The dog was euthanized because of clinical deterioration and unfavourable prognosis. Postmortem examination revealed multi-organ neoplastic infiltration, including the spinal cord. To our knowledge, this is the first case of acute myelomonocytic leukemia subtype M4 in a dog with spinal cord infiltration. Our findings hold importance for including myelomonocytic leukemia in the differential diagnosis of patients with neurological signs due to spinal cord localisation.