Definition of Polycythemia
Polycythemia, also called erythrocytosis, refers to an increase in the number or concentration of circulating red blood cells (RBCs). Several distinct forms of polycythemia - relative, transient and absolute - occur in dogs. Relative polycythemia can be caused by anything that reduces the liquid part of blood, such as dehydration, bleeding, vomiting, diarrhea and kidney disease. Transient polycythemia is triggered by excitement, fear, anger, surprise or anything that make the spleen contract, injecting RBCs into circulation. Absolute polycythemia occurs when the bone marrow increases production of red blood cells. Dogs with any type of polycythemia can have behavioral changes, difficulty walking, nose bleeds, red or pale mucous membranes, breathing problems and impaired vision. They may become weak, disoriented and fatigued. Some develop seizures, uncontrollable shaking and other symptoms. It is important to figure out which type of polycythemia a dog has to develop an appropriate treatment protocol.