In describing the symptoms of various diseases in these blogs, I occasionally mention anemia. In fact, we have a whole blog dedicated to one specific kind of anemia (immune-mediated hemolytic anemia). But I recently came to the realization that I have neglected to adequately explain anemia, what causes it and what to do about it! That, friends, is about to change.
Anemia occurs when the number of red blood cells in the body fall below normal. Because red blood cells are made up of hemoglobin, which carries oxygen, when red blood cell numbers are low, so is our pet’s (or our own!) hemoglobin level. And when hemoglobin levels are low, the oxygen-carrying capacity of the blood is also low, resulting in poor oxygenation of the tissues of the body.
Anemia can be classified as regenerative or non-regenerative. These names are fairly descriptive in that with regenerative anemia, the bone marrow is working hard to pump out new red blood cells in an attempt to replace the missing ones, and with non-regenerative anemia, it’s not.
Regenerative anemia occurs either due to blood loss or an abnormal breakdown of red blood cells, called hemolysis, which happen for many reasons. The most common reason is the aforementioned immune-mediated hemolytic anemia, but other causes include blood parasites like Babesia and Mycoplasma.
Blood loss may seem obvious, but it’s not always apparent. Obviously, traumatic external injuries that cause blood loss will be easy to spot, but some conditions result in chronic, low-level internal bleeding that pet parents may not notice. Gastric ulcers that cause bleeding are a good example, as are intestinal parasites that feed on our pet’s blood. External parasites like fleas and ticks also feed on our pet’s blood and have the potential to cause anemia, especially in young pets. In many cases, the anemia only becomes apparent when it is severe enough to cause lethargy in our pets.
Non-regenerative anemia occurs when the bone marrow fails to respond to an anemic condition. Sometimes the bone marrow simply does not make red blood cells, and sometimes the red blood cells it makes are abnormal and therefore not released into circulation.
Clinical signs of anemia include pale gums, lethargy, exercise intolerance and labored breathing. The diagnosis of anemia is made by running blood tests to check the level of red blood cells, but these tests do little to determine the underlying cause of the anemia. A thorough exam coupled with other diagnostics like blood tests, X-rays and possibly bone marrow aspirates will start the ball rolling on discovering the underlying cause.
The treatment of anemia is as varied as its causes. Severe cases will require blood transfusions while other diagnostics are being performed. Once a cause is found, it may be several days to weeks before your pet is feeling back to her old self as her red blood cell levels rebound.
Anemia can be a costly condition. Even those cases with an obvious cause, like fleas, may need hospitalization for oxygen therapy or blood transfusions. The cost of possible further diagnostics only adds to the stress of an emergency visit with a sick pet. It’s at times like these that pet health insurance comes in the most handy. Without financial constraints, you can focus on the task at hand – getting your pet well.