The Two Faces of IMHA

IMHA = Immune Mediated Hemolytic Anemia


In other words, for some reason, the body is attacking and breaking down it's own red blood cells (RBC's), resulting in variable levels of anemia and potentially death.


The past few weeks, I have encountered two cases of IMHA without apparent cause. I say this because we do know that sometimes, granted rarely, it can occur as a sequelae to vaccinations. This usually happens with certain vaccines and/or if there are multiple vaccines given but generally within a week or so of them being administered.


Both of the patients I am referring to had no vaccines, were not on any medications and as far as the owners know, did not get into anything.


It can be spontaneous and idiopathic (meaning we simply don't know the root cause). This is especially true in Cocker Spaniels who are over represented as a breed for this condition.


Not in my 2 cases. One was a young Chihuahua, one was a middle aged Shih Tzu.


The Chihuahua is doing great on our standard treatment of prednisone at immunosuppressive doses. We need to stop his body from attacking his own cells. We can start to wean him down and monitor his PCV (packed cell volume). He may be fine on no pred, low dose pred or may crash and relapse. There is NO predicting with this condition.


The second patient, a Shih Tzu, is not so lucky. She had 2 blood tranfusions and was put on 3 medications to help (by another animal hospital) before I even saw her. She came in with her PCV already starting to drop. She declined further by the next day and I knew she needed to get sent to the internal medicine specialists. They gave her a 20% chance with everything they could give her and a few thousand dollars. The owners felt that owed the cute little dog that much as she had been there for the young lady through thick and thin of life and love. I would have done the same - 20% is not 0%!  So far, she's with us, but it doesn't look good. 


This disease frustrates us as it is often so unpredictable, and like regulating a diabetic, often an "art" in knowing when to change dosages, etc. 


Sometimes the only symptoms are vague ones - the dog is a little off, a little "lethargic" etc. This is why I never ignore an owner's concern about changes in their pet's behavior. You shouldn't either.