Diagnosis and Management of Erythrocytosis in Companion Animals

Presentation Description / Summary: Erythrocytosis or an elevated hematocrit/hemoglobin/ RBC count is a common occurrence as a sequela to dehydration and splenic contraction and is termed relative erythrocytosis. An elevated hematocrit/hemoglobin/RBC count can also be normal in certain breeds. When erythrocytosis is persistent after rehydration, resolution of splenic contraction and is not thought to be breed related, then a diagnostic investigation is warranted to determine if the erythrocytosis is primary, meaning a disorder of the bone marrow where red blood cells are produced independently of erythropoietin or secondary due to an increase in erythropoietin due to hypoxia or neoplasia. True polycythemia vera, as defined by the presence of a JAK-2 mutation appears to be very uncommon in companion animals. Using a case example of a dog with erythrocytosis and guidance from the human literature, the differential diagnosis and diagnostic pathways for a companion animal with erythrocytosis will be outlined in a step wise manner. Treatment options for polycythemia vera and other forms of erythrocytosis will be described.

Learner Outcomes: Attendees at this presentation will be able to: 1. Define polycythemia and erythrocytosis and differentiate primary from secondary from relative erythrocytosis. 2. Understand the differential diagnosis and diagnostic pathway for dogs and cats with erythrocytosis. 3. Know treatment options available for companion animals with erythrocytosis.