IMMUNE MEDIATED HEMOLYTIC ANEMIA (IMHA)
IMHA is a condition in which the dog’s immune system attacks his own red blood cells. One of the major functions of the red blood cells is to carry oxygen from the lungs to all other major organs and tissues in the body. Once the body destroys the majority of the red blood cells the body becomes starved for oxygen. IMHA can be triggered by cancer, infections, vaccines, medications or some other recent stress event, but sometimes no clear cause can be established. It is a life threatening disease and it strikes fast and hard.
Symtoms of IMHA include:
Pale or yellow tinged gums
Loss of appetite
Conventional treatment consists of immune suppression drugs and supportive care, such as blood transfusions. The most commonly prescribed medication to help control this disease is a steroid called prednisone. The medication therapy must continue until there is evidence that the anemia has resolved and there is no ongoing destruction of red blood cells. This requires frequent recheck examinations to monitor the success of therapy. In conjunction with prednisone, other medications may be required to adequately suppress the immune system and control clinical signs. Drugs like cyclophosphamide, azathioprine or cyclosporine may be recommended. These drugs can have more severe side effects than prednisone. In some dogs, the destruction of the red blood cells is so severe that a life-threatening anemia can occur. Blood transfusions may be necessary to stabilize these pets until the bone marrow can keep up with the demand for red blood cells and until the drugs suppressing the immune system have time to work.
Prognosis for the disease is highly variable and depends on the underlying cause if one is present, complications related to the disease or drug therapy, and the response to treatment. Relapses can occur months to years after the initial episode.