Puppy's IMHA and high WBC count? – Page 3

Keymaster

Hi Nicole,
The important values to watch are the reticulocytes.
Dec 29 2016:
% Reticulocyte 0.7
Reticulocyte 37.1

Jan 10 2017
% Reticulocyte 1.4
Reticulocyte 65.8

Reticulocytes are the immature “new” cells that the bone marrow makes in response to the body cells “asking” for more oxygen. Anemia is really that, a shortage of O2 to the body cells followed by a complex series of events that should happen when the body sends out that SOS.

In our daily lives, we destroy old worn out blood cells and replace them on a daily basis. So reticulocytes are always in small quantities in our blood. They look a bit different than mature red blood cells, with a bluish “reticular” material inside the cells. They are also a bit larger in their juvenile state. In fact, to an automated analyzer they can almost appear to look the same as white blood cells. The vet must take this into account when viewing the CBC results.

So in a healthy human or dog, as we destroy and replace our old RBC, we maintain a very specific value for reticulocytes for our everyday needs. Those values are 60,000 absolute reticulocytes or approximately 1% if the total blood elements, give or take a bit either way. Any human or dog that has anemia and has a value less than these values has bone marrow that is not responding properly. The greater the anemia (measured by a value lower than 38% hematocrit or PCV and a lower than normal amount of hemoglobin inside the RBC), the greater the response must be by the bone marrow to be considered regenerative.

So compare a hematocrit of 37% and hemoglobin of 135 in Dec with a hematocrit of 35% and hemoglobin of 126 Jan 10, what do you see that is different? Yes, the hematocrit and hemoglobin are lower. That means that the RBC have slightly less capability of carrying the right amount of O2 to the body cells, but not by much.

Now compare the two values of reticulocytes, what do you see?
Dec 29 2016:
% Reticulocyte 0.7
Reticulocyte 37.1

Jan 10 2017
% Reticulocyte 1.4
Reticulocyte 65.8

Yes, you have seen that in Dec the bone marrow was not responding well to the need for O2 and the reticulocyte values are low, less than 60,000 and 1%. Those two values should have been higher. 37% is just a very tiny anemia, not much. But there still should have been a sufficient response to return the body to normal.

In Jan we see that the hematocrit is 35%, and the hemoglobin has dropped a bit. And bingo, you see that the bone marrow has responded and now the value is 65,800 and 1.4%. For mild anemia this is a very moderate response.

What would be important to watch is if this regenerative response continues at the next CBC. Remember that once the hematocrit reaches around 37 – 38% the body accepts that as normal and it will go back to only producing about 60,000, 1% reticuloyctes to replace old RBC. So don’t expect a massive response at this point, considering how small the anemia is.

One thing of importance to factor in is that the WBC seem to have risen from one test to the next and the number of red blood cells have dropped from 5.3 million to 4.7 million.
Dec
WBC 21.5
RBC 5.3

Jan
WBC 22.3
RBC 4.7

I think, (though your vet should also confirm), that this is an errant value and that these extra white blood cells are actually those big reticulocytes mimicking WBC. They can determine if this is true by running something called a differential, that details the WBC in more detail, in that they can usually figure out if the WBC are truly high or just reticulocytes.

Reticulocytes are in the blood a short time, only 3-5 days, before they drop the reticulated RNA, and mature into true RBC. So that test was 2 days ago and by the next time you do another CBC you will see different values, make sense?

The platelets are normal, which is always a good sign.

So we may want to begin to think about looking for something called anemia of chronic disease if these WBC values continue to remain highish, despite being on antibiotics. They would be a sign of something called an inflammatory condition, not really related to anemia, but perhaps a non responsive infection or a body organ that is “complaining” about the prednisone, first to come to mind is the pancreas and second is the liver.

Right now there is no danger, the anemia is so mild that it’s hardly worth the worry. I would like to see the PCV get up to 38% at least, but many dogs never get past 37% after these conditions, so not to worry. Are the gums nice and pink, is she acting like she feels better? Busy with the household, normal pottying, eating good? Those are the kinds of signs I look for and you are an expert at your own dog, the vet can’t come close to your ability to evaluate your dog!

Remember the body is always in a state of change, no single value really remains the same from day to day or even hour to hour, even in a healthy body. When we grab a CBC, it is a tiny momentary snap shot that is dependent on many things like when the last meal was, how hydrated your dog was, was your dog stressed out by the clinic, did the tech make some critical mistakes doing the blood draw and damage the sample, did the sample sit out too long and the blood changed for the worse? I wish I could say that every vet clinic has been careful about these things, but sadly that is not true.

So having a few CBC to compare will give a better idea of what is really happening. If you have questions, please ask,
my best, patrice

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