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Polycythemia Vera
By David Kerr, DVM. Edited by Robin Downing, DVM, CVPP, DAAPM.
Medical Conditions
What is polycythemia vera, and what are the symptoms?
Polycythemia vera, or “true” polycythemia, is a rare disease of dogs and cats in which too many red blood cells (RBCs) are produced by the bone marrow. This is the opposite of anemia, in which there are too few red blood cells.
"Animals with thicker blood from polycythemia feel tired, sluggish, and weak and may even have seizures."
Blood is composed of cells and fluid. The cell component is a mixture of red blood cells to carry oxygen, white blood cells to fight infection, and platelets to form clots and prevent bleeding. The fluid component of blood is called plasma and consists of proteins, antibodies, electrolytes, and water. Plasma carries blood cells and nutrients to the tissues of the body. Normally, the RBCs account for 35% to 55% of the blood volume and the plasma accounts for 45% to 65%. In these proportions, blood flows easily through arteries, veins, and capillaries to all parts of the body.