The packed cell volume is a simple test that helps to determine the relative amount of red blood cells that are in the body. Depending upon the age of the animal or if they are dehydrated will determine whether the PCV is high or low.
Red blood cells carry a protein called hemoglobin. It is the hemoglobin that gives red blood cells their red coloration. Hemoglobin is what carries oxygen through the body. When the PCV is low, which means there are fewer red blood cells, it is called anemia.
Anemia can be caused by external or internal bleeding, hemolysis (destruction of red blood cells) or because the body itself is not producing enough red blood cells in the bone marrow. A puppy, kitten or small dog can get anemia due to an infestation of fleas and or ticks.
In cats, the feline leukemia virus may cause anemia.
Onions, raw, cooked or dehydrated can also cause anemia. Ingestion of aspirin, zinc propylene glycol (found in some canned food) and acetaminophen, found in Tylenol can also lead to toxin reaction and blood loss.
To run a PCV, a small amount of blood is drawn and placed in a very thin tube then spun down. The veterinary assistant will usually be the one to draw the blood and run the test.
Treatment will depend upon the cause of the anemia. In some cases, a blood transfusion will be needed to increase the red blood cells in the body. IV fluids and certain medications may also need to be given to reverse the anemia.
To prevent anemia, do not give any drugs or over the counter medication unless specifically requested by the veterinarian. Remember that giving Tylenol can be fatal to both dogs and cats. There are many products on the market that will repel or kill fleas and ticks that are easy to apply. For felines, limit your cats contact with unfamiliar cats or by vaccinating for Feline Leukemia.