About Immune-mediated Hemolytic Anemia

Immune-mediated diseases result from the immune system inappropriately attacking and damaging or destroying parts of itself.  A number of important immune-mediated diseases including immune-mediated hemolytic anemia (IMHA) and immune-mediated thrombocytopenia (ITP; a disorder leading to platelet destruction and uncontrolled hemorrhage) unfortunately are common and very serious problems in pet dogs.   With IMHA, the body’s own immune system begins to hunt down and destroy its red blood cells resulting in oftentimes life-threatening anemia. IMHA can be frustrating for veterinarians and financially and emotionally challenging for pet owners. Sometimes the disease is considered primary and its cause is unknown. In other cases, it is deemed secondary, a complication of another underlying illness. Nor is treatment universal. It is not uncommon for dogs to fail to respond to the prescribed drugs or for the drugs to have unpleasant or unacceptable side effects. In other cases, dogs’ initial treatment is a success, but they then suffer a relapse. Life-saving blood transfusions and extensive diagnostic testing to determine if the IMHA is primary or secondary can also make it an expensive disease to treat for the animals’ owners. The mortality rate for dogs stricken with IMHA is 50 to 70 percent, a grim statistic that has not changed in decades.