Abstract
6 of 13 dogs developed absolute polycythemia and became hypertensive following proprioceptor depressor neurotomy. 4 of 6 dogs developed a decrease in red cell mass and total blood vol. after extensive paravertebral sympathectomy. Dogs with persistent hypertension and absolute polycythemia were subjected to extensive paravertebral sympathectomy which resulted in a decrease in blood pressure and disappearance of the polycythemia. A case report presents the effect of extensive paravertebral sympathectomy upon a [male] with intractable polycythemia rubra vera. He is asymptomatic 39 mos. after operation. A lengthy discussion compares the above data to the physiology of red blood cell formation by the bone marrow.