IMHA/IMTP

Immune Mediated Hemolytic Anemia AND Immune Mediated Thrombocytopenia (low platelets). 

 These conditions happen when the dog or cat’s own immune system views their red blood cells and/or platelets as “foreign” and begins destroying them. 

I had two cases recently that demonstrate two different ways this occurs. The first one was in a Bulldog with no known changes to anything in his environment or habits, no recents medications, trips anywhere, etc.  This dog came in very weak and icteric (the whites of his eyes, his skin and his gums were all yellow).  This dog had both low red blood cells and platelets. 

The other case was a young to middle aged border collie mix that came because the owner had noticed the dog was just “not doing right.”  He was a bit lethargic and not eating well. His gums were still a decent shade of pink. My concern was that the previous week he had been in for vaccines. We ran the blood work in house since we were heading into a weekend.  He ended up having a low red blood cell count. 

Case #1 was hospitalized and given a blood transfusion because his level was that low. He was also put on high (immunosuppressive) doses of steroids to STOP his body from breaking his cells down. He is (so far) doing very well.

Case #2 was not as severely anemic and was sent home with steroids. In this case, it’s probable that the vaccines initiated this process. 

In both cases, we like to keep them on steroids and do rechecks of the complete blood count to determine how and when to wean down (and we do this slowly!) off the medications.  

The first case seems to be a spontaneous event. This is commonly seen in some breeds like Cocker and English Spaniels.  

There are things other than vaccines that can cause this: exposure to certain drugs or chemicals, some infectious agents and cancers. 

The prognosis varies with the underlying cause of this. Some dogs require more medications than just steroids. There also can be relapses. Often dogs are on steroids LONG term at a low dose.  I've also seen dogs need multiple blood transfusions and cases where they don't make it or have to be euthanized. 


Cats don't seem to get this as often as dogs and in cats, finding the cause can be very difficult.  Tomorrow, I'll touch on causes of anemia in cats and a weird case.