What is primary absolute polycythemia?
Primary absolute polycythemia is a chronic bone marrow disorder that leads to the overproduction of red blood cells. Basically, the blood becomes too thick, because the solid components are elevated while the fluid component remains relatively normal. Primary absolute polycythemia is uncommon in cats and dogs and the cause is unknown.
Signs of the disorder can include brick red mucous membranes, bleeding tendencies, the passing of large amounts of urine, excessive thirst, lethargy, difficulty breathing, anorexia, behavioral changes, and neurological signs such as seizures, lack of coordination, weakness, confusion and blindness. These signs can appear abruptly or come on gradually and not every pet will have every sign.
Your veterinarian will use blood and urine tests to help diagnose polycythemia. In some cases other diagnostics may be needed.
The treatment for absolute primary polycythemia is reducing the thickness of the blood by reducing the number of red blood cells through therapeutic phlebotomy. Blood is removed from one of the cat’s central veins while IV fluids are administered through another vein to prevent the patient’s blood pressure from dropping dramatically because of rapid blood loss.
Emma is a beautiful, 11 year old, snowshoe kitty. She was diagnosed with polycythemia in 2009 when she started to have neurological symptoms. Emma came to us as a patient in 2012 and we have been treating Emma every 2 to 3 months since then. Emma is a sweet girl at home and even with us if we’re just petting her, but she REALLY hates us if we try to doctor her, so Emma needs anesthesia for her treatments.
After Emma is under anesthesia she is hooked up to our monitoring equipment. We monitor her ECG, heart rate, respiratory rate and blood oxygen levels. Since anesthesia can lower body temperature she is also wrapped in a warming pad made for animals called a Hot Dog. We then draw a small amount of blood to measure the percentage of red blood cells in Emma’s blood. The test we use is called a PCV (packed cell volume). A normal PCV for a cat is roughly 30 to 45%. Emma’s starting PCV is usually around 70%.
A catheter is placed in one of Emma’s jugular veins to draw blood from and another smaller catheter is place in one of her front legs to administer IV fluids through. We slowly draw 100 mLs of blood over the course of 45 minutes to 1 hour and simultaneously give IV fluids to replace the lost fluid volume. We then measure another PCV to make sure it is within the normal range before removing her catheters and letting Emma wake up, feeling as good as new.