This report describes a case of absolute erythrocytosis (hematocrit: 74%, hemoglobin: 24.2g/dl) in a dog with transmissible cutaneous venereal tumor. Hemoglobin and hematocrit returned to normal range after the treatment with vincristine. The remission of the erythrocytosis after treatment suggests a relationship between the neoplastic lesions and the hematological abnormality.
dog; transmissible venereal tumor; erythrocytosis; erythropoietin