Kw. Hinchcliff et al., DIAGNOSIS OF EDTA-DEPENDENT PSEUDOTHROMBOCYTOPENIA IN A HORSE, Journal of the American Veterinary Medical Association, 203(12), 1993, pp. 1715-1716
When thrombocytopenia is diagnosed in horses that do not have clinical
evidence of a bleeding tendency, EDTA-dependent pseudothrombocytopeni
a should be suspected. This type of thrombocytopenia is a result of pl
atelet clumping in blood that contains EDTA. The diagnosis of EDTA-dep
endent thrombocytopenia can be confirmed by screening blood films for
platelet clumps and by comparing platelet counts of paired blood sampl
es-one sample containing EDTA and the other sample containing heparin.