Errors in basophil enumeration with 3 veterinary hematology systems and observations on occurrence of basophils in dogs

Most automated hematology analyzers cannot detect canine or feline basophils. However, many veterinary laboratories continue to report basophils as part of the automated 5‐part differential leukocyte count for dogs and cats.

The study objectives were to evaluate the performance of the Sysmex XT‐2000iV, Advia 2120, and CELL‐DYN 3500 hematology analyzers in detecting basophils using blood from dogs, cats, and rabbits with basophilia and to investigate the concurrence of basophilia and other hematologic changes, sex, and breed in dogs.

One or more of the 3 hematology analyzers was used to analyze 11 canine blood samples with prominent basophilia (≥ 5%) based on a manual differential count. In addition, samples from 2 cats and 4 rabbits with basophilia were analyzed with the Advia 2120. Leukocyte cytograms were inspected for the likely location of basophil cell clusters. In a retrospective study of canine patients, reports of hematologic results that included a manual leukocyte differential count were identified using the laboratory information system and examined for the occurrence of basophilia and other hematologic changes, sex, and breed of the dogs.

Canine basophils were not detected by the Sysmex XT‐2000iV or CELL‐DYN 3500 analyzers, and neither canine nor feline basophils were detected by the Advia 2120. The Advia was able to detect basophils in rabbits. On the Sysmex cytogram canine basophils were found slightly above or together with neutrophils. On the Advia Perox cytogram canine basophils were located in upper part of the lymphocyte box and in the area of large unstained cells (LUC). Dogs with marked basophilia often had concurrent eosinophilia, and basophilia may be found more frequently in Rottweiler dogs than in other breeds. In 5 dogs with marked basophilia and without eosinophilia, marked thrombocytosis and anemia were noted.

Canine basophils were not detected by these automated hematology analyzers, and careful analysis of instrument graphical displays or increased LUC (Advia) may guide the need to examine a blood smear for basophils.