Autoimmune Hemolytic Anemia (AIHA) In Dogs - What Actually is It?

AIHA is diagnosed by detection of autoantibodies through use of the direct antiglobulin (Coombs') test. Antiglobulin serum is added to washed RBCs from the patient; agglutination indicates the presence of immunoglobulin, generally IgG, or C3 bound to the RBCs.

AIHA is a disorder in which the survival of red blood cells is shortened because the dog's immune system targets and destroys its own red blood cells. This type of immune dysfunction in which the host develops a reaction to and damages its own tissues is termed autoimmunity. AIHA is rarely associated with ulcerative colitis, occurring in approximately 0.6 to 1.7% of cases.

AIHA is most common in middle-aged dogs, and it is more often found in females than in males. Evidence of disease ranges in severity - symptoms can be mild and hardly noticeable, or severe symptoms may come on suddenly. AIHA is now defined as a process of accelerated red blood cell destruction due to the production of autoantibodies directed against the self red cell antigens.

Dogs that spend time around other dogs, that are boarded frequently, or who attend dog shows and dog parks, may need more careful monitoring than dogs that never leave home. Regardless of circumstance, the good news is that there are ways to minimize risk.

Dogs with serious infections or cancers in their body may also develop IMHA (immune mediated hemolytic anemia). The thought for the underlying cause is that something (e.g., vaccine, cancer cells) triggers the immune system to react and to create antibodies. Dogs with this symptom may benefit from very aggressive treatment with anticoagulants and cyclophosphamide, a potent immune system inhibitor. Blood transfusions can be used in dogs with IMHA if necessary but they can make the condition worse so most vets reserve this approach for dogs that appear to be in imminent danger of dying due to severe anemia.

Veterinarians are encouraged to work with specialists in their area for referrals. Veterinarians use genetics in a prescriptive manner. That is, they may use the results of a genetic test to recommend a specific treatment or an exact dosage of a drug.