Polycythemia is uncommon in dogs with chronic hypoxic pulmonary disease

Background Prolonged tissue hypoxia caused by chronic pulmonary disease is commonly regarded as an important mechanism in the development of secondary polycythemia, but little clinical data are available to support this hypothesis. Objective To study the prevalence and severity of erythrocytosis accompanying chronic hypoxic pulmonary disease in dogs. Animals Forty-seven dogs with hypoxic chronic pulmonary disease, 27 dogs with nonhypoxic chronic pulmonary disease, and 60 healthy controls. Methods Dogs with chronic pulmonary disease and chronic hypoxemia (partial pressure of arterial oxygen [PaO2] = 65%) was noted in any of the dogs. Red blood cell parameters were not associated with the severity of hypoxemia (correlation to PaO2: Erytr, r = -.14; Hb, r = -.21; Hct, r = -.14; P > .05 for all). Conclusions and Clinical Importance Polycythemia is uncommon, and usually mild if present, in dogs with chronic hypoxia caused by pulmonary disease.Peer reviewe