Representative photomicrographs of blood smears prepared from EDTA-anticoagulated blood (with and without warming) and citrate-anticoagulated blood (with or without added EDTA) from a cat with EDTA-dependent RBC agglutination (modified Wright’s stain, bar = 50 um). (A) Substantial RBC agglutination was evident in EDTA-anticoagulated blood, however there were no other RBC morphologic features consistent with an immune-mediated hemolytic anemia. (B) Warming the EDTA-anticoagulated blood to 37C for 30 minutes did not disperse the agglutinates. (C) Agglutination was not evident in a smear prepared from citrate-anticoagulated blood. (D) Agglutination recurred when the citrate-anticoagulated blood was placed into a vacutainer tube containing EDTA.
