Why Were Poikilocytes Seen In My Dog Or Cat's Blood ?













Ron Hines DVM PhD

To see what normal blood and urine values are, go here

For an explanation of causes of most abnormal blood and urine tests, go here

To see how tests are grouped, go here

Poikilocytes Seen In Your Pet's Blood Exam

Poikilocytosis describes shape abnormalities seen in your pet’s red blood cells (RBCs, erythrocytes). Red blood cells are normally produced by your dog or cat ’s bone marrow in endless look-alike clones. Since they only live a few months, untold numbers are created day after day - and one should look pretty much like the next.

When more than a few show differences in their uptake of coloring dyes (polychromasia) or appear differ in their size (anisocytosis) or, in this case, in their shapes; something is brewing.

Clinical pathologists have divided the various abnormal shapes that RBC assume into nine major groups - and probably got carried away in doing so. They are: sherocytes, leptocytes, target cells, stomatocytes, folded cells, speculated RBCs, schistocytes, acanthcytes and echinocytes.

There is a lot of overlap and guesswork as what might cause one or the other shape change - so using these shape abnormalities to diagnose what might be wrong with your dog or cat is really not very helpful.

However echinocytes can be due to too much anticoagulant in the blood collection tube, schistocytes correlate well with blood flow turbulence such as drawing the blood into the test tube to forcefully, target cells with anemia, and spherocytes with auto-immune disease.



Some Health Issues That Could Cause Poikilocytosis In General :

About one quarter of dogs that have babesiosis infections also have poikilocytosis. Poikilocytosis is also a common finding in dogs and cats treated with the anti-cancer drug, doxorubicin.

Poikilocytosis is also a feature in some cases of liver disease in cats. It can also be seen in crisis situations - like DIC (= disseminated Intravascular coagulation).

Just about anything that affects your pet's red blood cell formation in its bone marrow can be the cause of some of these abnormally shaped red cells being present.

Blood turbulence after the RBCs are formed (as in hemangiosarcoma tumors or certain heart diseases) have also been associated with poikilocytosis.

A novice technique in applying blood to a glass slide (blood smear) before submitting it to a laboratory can falsely distort the shape of dog and cat red blood cells as well (technique artifacts). Using too much EDTA anticoagulant while collecting the specimen of blood can do so as well.

Complementary Tests :

CBC/WBC and blood chemistry panel to begin with and further tests by your veterinarian based on those initial results