What is Immune-Mediated Hemolytic Anemia?
Immune-Mediated Hemolytic Anemia (IMHA) is a serious and often life threatening disorder in dogs and cats. IMHA results from an inappropriate immune response to the animals own red blood cells. IMHA can be classified as primary or secondary. With primary IMHA, the immune system malfunctions and begins to treat the red blood cells as if they were foreign invaders and begins to produce antibodies against the red blood cells. This response is similar to what would occur against bacteria. No underlying cause for this inappropriate reaction can be identified. With secondary IMHA, an underlying disease condition such as infection, parasites, cancer or a reaction to a drug or vaccine causes a change in the red blood cells, which in turn stimulates the immune system to attack the cells. The antibody response to the red blood cells can also cause “autoagglutination”, a condition where the red blood cells stick together like a cluster of grapes. Autoagglutination is often associated with clottin
