Comparative clinical study of canine and feline total blood cell count results with seven in-clinic and two commercial laboratory hematology analyzers

Abstract

Background: A CBC is an integral part of the assessment of health and disease in companion animals. While in the past newer technologies for CBC analysis were limited to large clinical pathology laboratories, several smaller and affordable automated hematology analyzers have been developed for in-clinic use.

Objectives: The purpose of this study was to compare CBC results generated by 7 in-clinic laser- and impedance-based hematology instruments and 2 commercial laboratory analyzers.

Methods: Over a 3-month period, fresh EDTA-anticoagulated blood samples from healthy and diseased dogs (n=260) and cats (n=110) were analyzed on the LaserCyte, ForCyte, MS45, Heska CBC, Scil Vet ABC, VetScan HMT, QBC Vet Autoread, CELL-DYN 3500, and ADVIA 120 analyzers. Results were compared by regression correlation (linear, Deming, Passing-Bablok) and Bland-Altman bias plots using the ADVIA as the criterion standard for all analytes except HCT, which was compared with manual PCV. Precision, linearity, and carryover also were evaluated.

Results: For most analytes, the in-clinic analyzers and the CELL-DYN performed similarly and correlated well with the ADVIA. The biases ranged from -0.6 to 2.4 x 10(9)/L for WBC count, 0 to 0.9 x 10(12)/L for RBC count, -1.5 to 0.7 g/dL for hemoglobin concentration, -4.3 to 8.3 fL for MCV, and -69.3 to 77.2 x 10(9)/L for platelet count. Compared with PCV, the HCT on most analyzers had a bias from 0.1% to 7.2%. Canine reticulocyte counts on the LaserCyte and ForCyte correlated but had a negative bias compared with those on the ADVIA. Precision, linearity, and carryover results were excellent for most analyzers.

Conclusions: Total WBC and RBC counts were acceptable on all in-clinic hematology instruments studied, with limitations for some RBC parameters and platelet counts. Together with evaluation of a blood film, these in-clinic instruments can provide useful information on canine and feline patients in veterinary practices.

Figure 1

Bland-Altman plots for analytes and instruments with high numbers of flagged samples, differentiating between flagged (○) and unflagged (●) samples. The graph on the upper left shows WBC counts from the CELL-DYN 3500 for canine samples. Discrepant results are flagged. The graph on the upper right shows WBC counts from the CELL-DYN for feline samples. Most discrepant results are flagged. The graph on the lower left shows PLT counts from the Scil Vet ABC for feline samples. Many discrepant results, as well as many accurate results, are flagged. The graph on the lower right side shows PLT counts from the QBC VetAutoread for canine samples. Many discrepant results, as well as many accurate results, are flagged.