Graphic by Artur
Dr. Palazzolo’s last three articles about anemia took a hiatus while the vet was on break. Follow the link to be directed to the last three.
Anemia is not a disease; it is a sign of a disease. Whenever we have a pet that is diagnosed with anemia, we first need to determine if it is regenerative or nonregenerative. By doing this, we narrow the list of possible causes.
Anemia in Animals, Part 1—Anatomy of the Red Blood Cell (RBC)
There are many different causes to anemia. In this article, I will discuss two of the more common ones: anemia of chronic disease, and immune-mediated hemolytic anemia.
Anemia of chronic disease occurs when another system in the body suppresses the bone marrow from making RBCs. Diseases like infections and cancer fit into this category. Probably the most common cause of anemia of chronic disease is chronic kidney disease (CKD) in cats.
Anemia in Animals, Part 2—Physiology of the Red Blood Cell (RBC)
In addition to the chronicity of the disease affecting the bone marrow, the kidneys also have a specific role in making RBCs. This is because the kidneys secrete a hormone called erythropoietin. This hormone tells the bone marrow to make RBCs; without its presence, the bone marrow does not make them. In CKD, the kidneys do not secrete enough of this hormone, and the result is nonregenerative anemia.
CKD is diagnosed based on the slow progression of the anemia, the fact that it is a non-regenerative anemia, evidence of elevated creatinine in the bloodstream, and a urinalysis.
In immune-mediated hemolytic anemia, the immune system makes antibodies against RBCs. This affects the outer membrane of the red-blood cell and effectively destroys it. This anemia tends to come on quickly, unlike the anemia of chronic deficiency. The homeostatic mechanisms in the body do not have time to adjust, and the anemia tends to be severe.
We confirm immune-mediated hemolytic anemia with a test called a Coombs test. This is how our lab describes this test. Graphic courtesy of LBAH.
The disease’s diagnosis is based on the rapid onset of the problem, the severe degree of the problem, the fact that the anemia is regenerative, and also with special tests to determine if the immune system is involved.
In the final article, I will talk about how we treat these two common causes of anemia.