The Diagnosis of Anemia in Horses
  by Robert N. Oglesby DVM

Red blood cells are essential for carrying oxygen to the cells of our horses bodies. For optimum health and performance the mass of red blood cells must be also optimized. We measure red blood cell mass by taking a whole blood sample placing a small amount in a long thin tube and centrifuging it until all the cells are squeezed to one side. Then the column of red blood cells is compared to the total column of cells and fluid. The ratio of cell column over the total column is called the packed cell volume (PCV) or hematocrit (Hct).

Anemia is a frequently diagnosed disease in horses however there are some unique features of equine physiology that complicate the accurate diagnosis of anemia. Further complicating correct diagnosis is that there are significant differences in the normal hematocrit of different breeds of horses. The result is anemia is over diagnosed, even by equine veterinarians. Caution should be applied to the diagnosis of anemia in an otherwise healthy horse.

Besides anemia as a cause of serious of decreased performance, there are serious and life threatening diseases where anemia is the main cause of disease symptoms. This article discusses the clinical signs, accurate diagnosis of anemia, and the causes in horses. Links are provided to articles on the specific causes where further treatment is discussed.